Subscribe Now Subscribe Today
Abstract
Fulltext PDF
References
Research Article
 

Effects of Vacuum-packaging on the Microbiological, Chemical, Textural and Sensory Changes of the Solar Rack Dried Sardines During Chill Storage



Ogongo Bernard Ochieng, Odote Peter Michael Oduor and Mlanda Mwangemi Nyale
 
ABSTRACT

Solar dried clupeid sardine fishery storage along the Kenyan coast has always been carried out unhygienically using gunny bags kept under ambient conditions. Shelf life changes of the vacuum-packaged solar rack dried sardines during chill storage were therefore examined, to determine the occurring microbiological, chemical, textural and sensory changes in the gunny bag (GBP), control air (CAP), experimental air (EAP) and Experimental Vacuum Packaged (EVP) samples. Pouches (size: 15×22 cm) made of 12 μ-polyester laminated with 300 gauge low-density polyethylene were used for packaging. After packing, all the packs were iced with flake ice in the ratio of 1:1 and stored maintained in an insulated cooler box at 0-2°C. Thereafter, samples were analyzed periodically for chemical, microbiological, textural and sensory characteristics quality changes. Staphylococcus aureus, Enterobacteriaceae and Feacal streptococci counts were also determined at the packaging time and at sensory rejection time. Ambient stored Gunny bag and polythene air packaged samples had a shelf life of 14 and 30 days, respectively; chilled polythene air-packaged 45 days and chilled vacuum-packaged 90 days. Thus, vacuum-packaging in combination with chilling was found to be the best in delaying spoilage and thereby significantly extending dried fish products shelf life in tropical environments.

Services
Related Articles in ASCI
Similar Articles in this Journal
Search in Google Scholar
View Citation
Report Citation

 
  How to cite this article:

Ogongo Bernard Ochieng, Odote Peter Michael Oduor and Mlanda Mwangemi Nyale, 2015. Effects of Vacuum-packaging on the Microbiological, Chemical, Textural and Sensory Changes of the Solar Rack Dried Sardines During Chill Storage. Bacteriology Journal, 5: 25-39.

DOI: 10.3923/bj.2015.25.39

URL: https://scialert.net/abstract/?doi=bj.2015.25.39
 
Received: August 15, 2015; Accepted: October 22, 2015; Published: November 06, 2015

INTRODUCTION

Fish is perhaps among the most vulnerable world resources that its freshness which is considered a synonym for quality deteriorates rapidly (Ogongo et al., 2015; Dewi et al., 2011; Khan and Khan, 2001). This spoilage vulnerability coupled with the increasing demand for high quality fresh seafood, has intensified the search for methods and technologies for better fresh fish utilization. One of such major developments in food packaging anticipated for fulfilling fresh fish utilization challenges in stored products is packaging under vacuum or modified atmosphere conditions (Sivertsvik et al., 2002). This vacuum-packaging method represents a static form of hypobaric storage widely used in food industries because of its effectiveness in reducing oxidative reactions in the product at relatively low cost (Gopal et al., 1999). It can therefore supplement ice or refrigeration in delaying spoilage, extending shelf life, maintaining higher product quality, assuring product safety and reducing economic loss of stored fish and fishery products.

Texture being a manifestation of the rheological properties (Belton, 2003; Gallegos et al., 2004) of a food differs widely among different food types. As a result, fish texture differs widely from that of meat because it contains less connective tissue and the cross-links formed between collagen molecules are weaker thus resulting in a more tender structure. In addition, since many fish species do not have a strong flavour, texture becomes very important for consumer acceptability (Thybo and Martens, 2000; Ashie et al., 1996). Imitative tests that attempt to imitate (with instruments) the conditions to which the food is subjected in the mouth or on the plate have therefore been developed for texture measurement analyses. Thus, a more comprehensive description of fish texture is obtained using Texture Profile Analyses (TPA) methods described by Fisher et al. (2007), Mezger (2006), Bourne (1978), Breene (1975), Friedman et al. (1963) and Johnson et al. (1981).

Fresh seafood spoilage is mainly impacted by the Psychrotropic bacteria type of microorganisms (Adams et al., 1964) which antimicrobial agents such as sodium acetate have been used to prevent their growths in foods and improve food shelf life under different storage conditions (Kim et al., 1995). Sodium acetate is an approved United States Food and Drugs Administration (USFDA) flavouring and pH controlling agent. Zhuang et al. (1996) observed that it is effective in controlling natural microbial floral growth on refrigerated catfish fillets. However, temperature abuses on commercial vacuum packaged, or modified atmosphere-packaged fresh fillets, have resulted in rapid growth of Clostridium botulinum type E spores during refrigeration storage in between 1-4°C. This is because the organism is non-proteolytic and can grow and produce toxins at a very low temperature of 3.3°C. Although the incidence of botulinum from consumption of refrigerated food is exceedingly low, there have been several reported outbreaks mainly involving type E toxin associated with the consumption of fresh vacuum packed fish products (Huss, 1981).

Therefore, taking into consideration that collective works on various quality aspects including chemical, microbiological, textural and sensory of refrigerated vacuum-packaged stored fish products is scarce within the tropical region, this study undertook to report the effects of vacuum packaging on shelf life of the solar rack dried sardines assessed by chemical, microbiological, textural and sensory parameters during chill storage.

MATERIALS AND METHODS

Packing and storage of the solar rack dried sardines: This packing and storage study was carried out for a period of seven months beginning from August, 2014 to February, 2015 at Kenya Marine and Fisheries Research Institute (KMFRI) Mombasa, Kenya. Fresh sardine fish samples were obtained in bulk from the local Jasini artisanal fishermen in Vanga (S 04°40'16.11", E 039°13'36.96"), Kenya. They were then quickly transferred to large insulated cooler boxes containing crushed ice and transported to the processing sites where the solar rack dryers were installed in Jasini-Vanga next to the landing site. At the processing site, the fish samples were dried for five consecutive days using raised open rack dryers (consisting of an ivory mesh net, raised 0.30 m from the ground to allow for air movement). The dried samples were then divided into four lots. Lot I packed in gunny bag (GBP) and lot II which was polythene air-packed (CAP) and stored in ambient laboratory conditions were the controls. Lots III and IV contained experimental chilled samples for polythene air-packed (EAP) and vacuum-packed (EVP), respectively.

Pouches (size: 15×22 cm), made of 12 μ-polyester laminated with 300 gauge low-density polyethylene, were used for packaging of the dry sardine fish samples. Physical properties of the packaging material, such as heat-seal strength (ASTM., 1972), tensile strength and elongation at break, were determined in the machine direction and in the cross-direction as per, IS 2508 (1984). Oxygen transmission rate (ASTM., 1975) and water vapour transmission rate as per ASTM. (1987) were also determined. Dried sardine fish samples weighing between 200±5 g were placed in each pouch. Lot I samples were sealed by tying the gunny bags using sisal strings wound round their mouths. Lots II and III samples were sealed using an impulse heat-sealing machine whereas Lots IV samples were vacuum-packed at -1 bar pressure. A vacuum sealing machine-Model QS 400 VD supplied by M/s. Sevanna Electrical Appliances Pvt. Ltd., Kerala, India, was used for vacuum packing. Immediately after packing, all the packs were iced with flake ice in the ratio (1:1) fish: ice in an insulated cooler box and transported back to Kenya Marine and Fisheries Research laboratory for storage at chilling temperatures of between 0-2°C. Re-icing was done after draining off the melted ice every day to supplement the melting loss. Samples were thereafter drawn in triplicates from each lot at regular intervals and analyzed mean values for chemical, microbiological, textural and sensory parameters recorded.

Reagents and media: Chemicals used for the experiments were of Sigma brand, Analar grade or guaranteed reagent grade. Dehydrated bacteriological media, such as Plate Count Agar (PCA) (BBL Difco), Baired Parker agar (BP, Himedia), Kenners Faecal (KF) Agar (BBL Difco) and Violet Red Bile Glucose Agar (VRBGA, Oxoid) were used.

Chemical analysis: Proximate composition was determined by AOAC (1998) method. pH was determined according to APHA (1998) using a digital pH meter (Cyber scan 510, UK) after homogenizing 10 g of the fish sample with the same amount of distilled water. Total volatile base nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) were estimated by micro diffusion method (Conway, 1950). Thiobarbituric acid (TBA) value of the fish sample was estimated spectrophotometrically (Tarladgis et al., 1960).

Microbiological analysis: Twenty-five grams of fish were aseptically weighed and homogenized with 225 mL sterile 0.85% normal saline for 1 min in a Stomacher 400 lab blender (Seward medical, London, UK). The homogenized sample was serially diluted using 9 mL sterile saline for bacteriological analysis. Counts of Staphylococcus aureus (AOAC., 2002), Faecal Streptococci (USFDA., 1995) and Enterobacteriacea (Koutsoumanis and Nychas, 1999) were determined for fresh fish and for fish at the time of sensory rejection. Total Viable Counts (TVC) were determined in Plate Count Agar by the spread plate method (AOAC., 2002). Fish samples were tested for the presence of C. botulinum toxin as per FDA (2001).

Texture analysis: Texture Profile Analysis (TPA) was measured with a universal testing machine (Lloyd instruments LRX plus, UK), as described by Anderson et al. (1994), equipped with a load cell of 50 N. Dried sardine fish samples were cooked in 1.5% brine for 10 min, drained well and cooled to room temperature. Thereafter, texture profile analysis was performed on these cooked samples that have been compressed twice by a cylindrical probe of 50 mm diameter at a test speed of 12 mm min–1. The principle behind the usage of the cylindrical probe is that, as the probe is forced into the specimen, a shearing force acts, which causes the sample to deform or rupture.

Table 1: Sensory scores for taste panel studies

This produces a load showing curve resulting from the deformation. Hardness, cohesiveness, springiness and chewiness were calculated as defined in the texture analyzer user manual and TPA results tabulated using Nexygen software.

Sensory evaluation: Sensory analysis is the most used traditional method for fish quality judgments. Thus, various sensory characteristics such as appearance, texture, odour and flavour were evaluated by five trained panelists and scores based on a nine-point hedonic scale as described by Amerine et al. (1965). Taste panel scoring of the test fish samples was conducted after boiling the packaging polythene dressed samples in 1.5% brine for 10 min. A sensory score of 4 was taken as the acceptability borderline (Table 1).

RESULTS AND DISCUSSION

Test samples proximate composition and physical properties of the packaging material: Proximate composition of freshly landed test samples showed 75.7% moisture, 3.04% crude fat, 20.3% crude protein and 0.98% ash. The physical property of the used packaging material was also as presented in Table 2.

Chemical assessment
Changes in Thiobarbituric Acid (TBA): Changes in TBA value, which is a measure of oxidative rancidity of the product, were as presented in Fig. 1. The values respectively increased from an initial 0.08-0.5, 0.35, 0.32 and 0.25 mg malonaldehyde kg–1 of fish in GBP, CAP, EAP and EVP samples on the 90th day of storage. The results indicated an increasing trend in all of the samples during storage. Similar observations have been previously observed by Huang et al. (1994), Josephson et al. (1985) and Nolan et al. (1989). All polythene air (CAP and EAP) and vacuum packed (EVP) samples exhibited lower TBA values than the gunny bag packed control sample. On the same note, chilled samples exhibited even lower values than the polythene air packed (CAP) sample stored in ambient laboratory conditions. This TBA value reduction during chill storage is in agreement with Rajesh et al. (2002) observations. The rate of fat oxidation which has been observed to increase during cold storage was however reduced by vacuum-packing and icing as stated in the works of Baldrati et al. (1982) and Varga et al. (1980). All of the samples TBA values were also found to be within the acceptability limit range of 1-2 mg malonaldehyde kg–1 of fish sample (Lakshmanan, 2000) throughout the storage period.

Changes in pH: Variations in pH values during storage were as depicted in Fig. 2. The initial pH value was 6.5 and on storage, the value increased gradually in GBP. In CAP, EAP and EVP samples, the value decreased initially and then increased.

Fig. 1:
Changes in TBA values of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Fig. 2:
Changes in pH of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Table 2: Physical properties of the packaging material
MD: Machine direction, CD: Cross-direction

The observed slight decreases in pH values may be attributed to the dissolution of CO2 in the fish muscle. Similar observations were made by McMeekin et al. (1982) who reported a decline in pH of vacuum packed sand flat head fillets stored for 6 days at 4°C. Several authors have also reported decreasing pH values with increases in the concentration of atmospheric CO2 (Lannelongue et al., 1982; Tiffney and Mills, 1982). The increases observed in the pH values may also be attributed to the production of volatile base compounds such as ammonia through spoilage bacterial activity (Cann et al., 1983; Reddy et al., 1995).

Fig. 3:
Changes in TVB-N values of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Fig. 4:
Changes in TMA-N values of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Changes in Total Volatile Base Nitrogen (TVB-N): The TVB-N in fish is mainly composed of ammonia, primary, secondary and tertiary amines (Beatty, 1938). A level of 35-40 mg TVB-N 100 g–1 of fish muscle is usually regarded as spoilt (Lakshmanan, 2000). Increased TVB-N value change during storage were as shown in Fig. 3 where TVB-N contents increased from an initial value of 5.6-33.5 mg % in GBP, 30.5 mg % in CAP, 22.5 mg % in EAP and 19.5 mg % in EVP on the 90th day of storage. Values were found to be lower in the case of chilled experimental sample packs (EAP and EVP) than in the ambient sample control packs (GBP and CAP). Similar results have been reported by Shalini et al. (2000) during refrigerated storage of sodium acetate-treated vacuum-packed L. lentjan fillets. Low levels of TVB-N in treated samples were due to either a reduced bacterial population or decreased capacity of bacteria for oxidative deamination of non-protein nitrogen compounds or both (Banks et al., 1980). However, even though all samples were within the acceptability limits throughout the storage period, both control samples nearly reached the lower rejection limit target of 35 mg TVB-N 100 g–1 of fish muscle.

Changes in trimethylamine nitrogen (TMA-N): TMA-N changes which are also used as fish freshness deciding quality index (Parkin et al., 1982) were as shown in Fig. 4.

Fig. 5:
Changes in total viable counts (20°C) of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Fig. 6:
Changes in total viable counts (37°C) of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

All samples showed an increasing trend in their TMA-N values with slightly higher increments observed in both the control packs (GBP and CAP). The TMA-N contents increased from an initial 1.4-7.4 mg % in GBP, 6.8 mg % in CAP, 6.3 mg % in EAP and 5.7 mg % in EVP during the whole period of storage. The present study’s result are in agreement with those of Ishida et al. (1976) and Lakshmanan et al. (1996) who both reported that TMA-N formation slows down noticeably in low refrigeration temperature storage conditions above 0°C. This slowing down of TMA-N in reaching 10-15 mg 100 g–1 in fish muscle that is considered as the limits of acceptability for human consumption in chilled fish (Connell, 1975), might be attributed to the inhibitory effect of the lower temperatures on bacterial growth. Similar observations had also been previously reported by both Shalini et al. (2000) and Rajesh et al. (2002).

Microbiological analysis
Changes in Total Viable Counts (TVC): The initial TVC of dried sardines at 20 and 37°C were 4.98 and 4.94 log10 CFU g–1, respectively. Dried sardines’ TVC changes at 20 and 37°C during the study were as shown in Fig. 5 and 6, respectively. In the 20°C GBP, CAP and EAP experiment samples, TVC rose continuously and reached about 107 CFU g–1 on the 14th, 30th and 45th days of storage when the fishes were, respectively deemed spoilt based on sensory scores. The rise may be attributed to the bacterial growth increases when still using the trapped airs inside the packaging materials before exhaustion. It has also long been known that fish microbiological count determinations at between 20-25°C are always much higher than those determined at 37°C (Castell et al., 1948; Liston, 1957) as exhibited by the present study (Fig. 6). The study results also confirmed the earlier findings of Leung et al. (1992), Huang et al. (1994), Lyon and Reddmann (2000) and Ozogul et al. (2000, 2004) that bacteria grows more quickly in fish stored in air than when Vacuum-Packed (VP) at 0°C.

Changes in counts of Enterobacteriaceae, S. aureus and feacal streptococci: The initial dried sardines’ Enterobacteriaceae counts were 2.81 log10 CFU g–1 and by the end of storage, a 0.2 log increase was noticed in EAP and EVP samples whereas 0.4 log increases was observed in CAP samples. This was in agreement with the works on temperate marine fish (Drosinos et al., 1997; Koutsoumanis and Nychas, 1999) and temperate fresh water fish work of Savvaidis et al. (2002) where S. aureus count was 1.2 log10 CFU g–1. All samples registered a 0.2 log reduction counts on the day of sensory rejections which were all within the prescribed limits for fresh dried fish recommended by ICMSF (1986). Thus, the study results indicate good microbiological quality of the dried sardine samples stored at 0-2°C.

Clostridium botulinum: Clostridium botulinum toxin was not detected in any of the samples throughout the storage period indicating that there was no temperature abuse during storage. This negative C. botulinum toxin result assay is in accordance with the vacuum-packed fish fillets work reported by Lilly Jr. and Kautter (1990) and that for modified atmospheric packed salmon fillets by Reddy et al. (1997).

Texture analysis
Changes in Hardness 1 and Hardness 2: Generally, since hardness normally refers to the peak force during the compressive part of the test, hardness 1 therefore, refers to the peak force during first compression whereas, 2 refer to the peak force during the second compression. Hardness 1 and 2 were found decreasing in all the samples during storage with their changes being represented in Fig. 7 and 8, respectively. Hardness 1, decreased respectively from the initial 1.99-1.86, 1.60, 1.54 and 1.4 kgf in GBP, CAP, EAP and EVP samples by the 90th day of storage. The values of both the experimental chilled air (EAP) and vacuum (EVP) packed samples were found to be comparatively lower than those of control ambient gunny bag (GBP) and air packed (CAP) samples. Hardness 2 values for GBP, CAP, EAP and EVP samples decreased respectively from the initial 1.77-1.59, 1.3, 1.24 and 1.09 kgf on the 90th day of storage. In CAP, EAP and EVP samples were also found to have lower Hardness 2 values than GBP samples. These Hardness 1 and 2 value decreases might be attributed to the weakening of connective tissues of the fish muscles during storage.

The results were in agreement with those of Sato et al. (1997) who demonstrated that sardine pericellular tissue weakening was correlated with softening. On the other hand, Azam et al. (1989) who studied the killing method effect on rainbow trout quality during storage on ice also observed a similar significant softening of both raw and cooked fillets during storage using instrumental measurement (Steven’s Compression Response Analyzer, SCRA) method. This was further confirmed by Ando et al. (1991) in addition to similar observations being made also by Hatae et al. (1985) who reported a softening of the texture in several fish species stored at 4°C using General Foods (GF) texturometer.

Fig. 7:
Changes in hardness 1 values of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Fig. 8:
Changes in hardness 2 values of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Changes in cohesiveness, springiness and chewiness: Cohesiveness being the ratio of work done during the second compression divided by work done during the first compression is an indication of the materials’ viscoelasticity. A value of 1 indicates total materials’ elasticity whereas 0 indicates that the sample did not recover at all. The study’s cohesiveness value changes were as depicted in Fig. 9 in which respective slight decreases from the initial 0.34-0.22, 0.20, 0.18 and 0.16 were observed in GBP, CAP, EAP and EVP samples at the end of 90 days of storage. This indicated that there was no much change in the internal bonding of the fish muscles during storage.

Springiness (the elastic or recovering property of the fish muscle during compression) changes of the dried sardine samples during the study period were as contained in Fig. 10. In general, a decreasing trend was observed in all test samples during storage. The values respectively decreased from the initial 1.01-0.92, 0.82, 0.72 and 0.70 mm in GBP, CAP, EAP and EVP samples during storage. The values indicated that the fish muscles lost their elasticity during storage.

The values of chewiness that refers to the work done were also as represented in Fig. 11 in which chewiness was found to have decreased in all the samples indicating that the fish muscles became soft during storage.

Fig. 9:
Changes in cohesiveness of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Fig. 10:
Changes in springiness values of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Fig. 11:
Changes in chewiness of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

Sensory analysis: Changes in sensory scores were as presented in Fig. 12 in which there were significant declines in the GBP, CAP and EAP sample packs with increasing storage period.

Fig. 12:
Changes in overall sensory scores of dried sardines packed differently and stored in a condition of between 0-2°C. Bars represent ±Standard errors

This resulted in fish spoilages giving rise to the subsequent development of strongly fishy, rancid and putrid odours that made the taste panelists to clearly reject the fishes for human consumption by assignment of sensory scores that were lower than 4. Sensory scores in general however declined respectively from the initial pH value of 8.6-3.2, 2.8, 2.4 and 6 in cases of GBP, CAP, EAP and EVP samples. Thus, GBP, CAP, EAP and EVP samples were, respectively acceptable for up to 14, 30 and 45 days whereas, EVP samples remained in good condition up to the 90th day making chilled vacuum-packaging to safely extend the dried sardine samples shelf life for up to 90 days at 0-2°C.

CONCLUSION

The results of the study revealed that polythene air packaging with chilling would not be of much use in prolonging the dried samples shelf life beyond 45 days of storage. Therefore, since several authors have also successfully demonstrated the multiple barrier technology or hurdle concept in which several factors are combined or superimposed at sub-inhibitory concentrations that can effectively control micro organisms in refrigerated seafood’s the study results clearly suggest that a combination of different factors such as polythene, vacuum-packaging and storage at refrigerated temperature could be used to prolong the dried sardines’ shelf life to a great extent. It should however be emphasized that this chilled polythene vacuum-packaging success is completely dependent on the initial quality of the processed fish and on adequate temperature control throughout the storage period.

ACKNOWLEDGMENTS

We are grateful to World Bank funded Kenya Coastal Development Project (KCDP)-Grant Agreement Number:-KE 4801 for funding the study. Thanks also go to Raymond Ruwa, Maurice Omega, James Emuria, Christine Migwi, Winnie Atieno and Winnie Jefwa for their assistance with laboratory work during the project. Special thanks also go to the Director and the entire Kenya Marine and Fisheries Research Institute (KMFRI) staff for providing laboratory space and good will for the accomplishment of the study.

REFERENCES
AOAC., 1998. Official Methods of Analysis. 16th Edn., Association of Official Analytical Chemists, Washington, DC., USA.

AOAC., 2002. Official Methods of Analysis of AOAC International. 17th Edn., Association of Official Analytical Chemistry, USA.

APHA., 1998. Standard Methods for the Examination of Water and Wastewater. 20th Edn., American Public Health Association, Washington, DC., USA., ISBN-13: 9780875532356, Pages: 1220.

ASTM., 1972. Standard Method of Test for Peel or Stripping Strength of Adhesive Boards. American Society for Testing and Materials, Philadelphia.

ASTM., 1975. Standard Method of Test for Gas Transmission Rate of Plastic Film Sheeting. American Society for Testing and Materials, Philadelphia.

ASTM., 1987. Standard Operating Procedure for the Determination of Water Vapour Transmission Rate of Packaging Materials. American Society for Testing and Materials, Philadelphia, USA., pp: 96-80.

Adams, R., L. Farber and P. Lerke, 1964. Bacteriology of spoilage of fish muscle. II. Incidence of spoilers during spoilage. Applied Microbiol., 12: 277-279.
Direct Link  |  

Amerine, M.A., R.M. Pangborn and E.B. Roessler, 1965. Principles of Sensory Evaluation of Foods. 2nd Edn., Academic Press, New York, Pages: 602.

Anderson, U.B., A.N. Stomsnes, M.S. Thomassen and K. Steinsholt, 1994. Fillet gaping in farmed Atlantic salmon. J. Agric. Sci., 8: 165-179.

Ando, M., H. Toyohara, Y. Shimizu and M. Sakaguchi, 1991. Post-mortem tenderisation of rainbow trout (Oncorhyncus mykiss) muscle caused by gradual disintegration of the extracellular matrix structure. J. Sci. Food Agric., 55: 589-597.
CrossRef  |  Direct Link  |  

Ashie, I.N.A., J.P. Smith, B.K. Simpson and N.F. Haard, 1996. Spoilage and shelf‐life extension of fresh fish and shellfish. Crit. Rev. Food Sci. Nutr., 36: 87-121.
CrossRef  |  Direct Link  |  

Azam, K., I.M. Mackie and J. Smith, 1989. The effect of slaughter method on the quality of rainbow trout (Salmo gairdneri) during storage on ice. Int. J. Food Sci. Technol., 24: 69-79.
CrossRef  |  Direct Link  |  

Baldrati, G., P. Pirazzali, E. Broglia, F. Ambroggi and I. Incerti, 1982. Effect of freezing method and cold storage on quality of Sardines (Clupea pilchardus). Ind. Conserv., 57: 260-271.

Banks, H., R. Nickelson II and G. Finne, 1980. Shelf-life studies on carbon dioxide packaged finfist from the gulf of Mexico. J. Food Sci., 45: 157-162.
CrossRef  |  Direct Link  |  

Beatty, S.A., 1938. Studies of fish spoilage: II. The origin of trimethylamine produced during the spoilage of cod muscle press juice. J. Fish. Board Can., 4: 63-68.
CrossRef  |  Direct Link  |  

Belton, P.S., 2003. The Molecular Basis of Dough Theology. In: Bread Making: Improving Quality, Cauvain, S.P. (Ed). CRC Press, Boca Raton, USA.

Bourne, M.C., 1978. Texture profile analysis. Food Technol., 32: 62-66.
Direct Link  |  

Breene, W.M., 1975. Application of texture profile analysis to instrumental food texture evaluation. J. Texture Stud., 6: 53-82.
CrossRef  |  Direct Link  |  

Cann, D.L., G.L. Smith and N.G. Houston, 1983. Further studies on marine fish stored under modified atmosphere packaging. Ministry of Agriculture Fisheries and Food, Torry Research Station, Aberdeen.

Castell, C.H., G.W. Anderson and H. Pivnick, 1948. Relation of bacterial counts to quality of cod fillets. J. Fish. Board Can., 7: 378-388.
CrossRef  |  Direct Link  |  

Connell, J.J., 1975. Control of Fish Quality. Fishing News Books Ltd., UK., pp: 137.

Conway, E.J., 1950. Microdiffusion Analysis and Volumetric Error. 3rd Edn., Crosby Lokswood and Sons, Ltd., London, Pages: 391.

Dewi, R.S., Nurul Huda and R. Ahmad, 2011. Changes in the physicochemical properties, microstructure and sensory characteristics of shark dendeng using different drying methods. Am. J. Food Technol., 6: 149-157.
CrossRef  |  Direct Link  |  

Drosinos, E.H., K. Lambropoulou, E. Mitre and G.J. Nychas, 1997. Attributes of fresh gilt-head seabream (Sparus aurata) fillets treated with potassium sorbate, sodium gluconate and stored under a modified atmosphere at 0±1°C. J. Applied Microbiol., 83: 569-575.
CrossRef  |  Direct Link  |  

FDA., 2001. Clostridium Botulinum Toxin Formation. In: Fish and Fish Products Hazards and Controls Guidance, FDA (Ed.). 3rd Edn., Food and Drug Administration, Washington, DC., pp: 167-190.

Fisher, D.T., S.A. Clayton, D.V. Boger and P.J. Scales, 2007. The bucket rheometer for shear stress-shear rate measurement of industrial suspensions. J. Rheol., 51: 821-831.
CrossRef  |  Direct Link  |  

Friedman, H.H., J.E. Whitney and A.S. Szczesniak, 1963. The texturometer-a new instrument for objective texture measurement. J. Food Sci., 28: 390-396.
CrossRef  |  Direct Link  |  

Gallegos, C., J.M. Franco and P. Partal, 2004. Rheology of Food Dispersions. In: Rheology Reviews 2004, Binding, D.M. and K. Walters (Ed.). The British Society of Rheology, Aberystwyth, pp: 19-65.

Gopal, T.K.S., J. Joseph and K.K. Balachandran, 1999. Development of Fish Products Employing Hurdle Technology. In: Preservation of Food by Hurdle Technology, Gopal, T.K.S., J. Joseph and K.K. Balachandran (Ed.). DFRL, Mysore, pp: 93-103.

Hatae, K., S. Tamari, K. Miyanaga and J. Matsumoto, 1985. Species difference and changes in the physical properties of fish muscle as freshness decreases. Bull. Jpn. Soc. Sci. Fish, 51: 1155-1161.
CrossRef  |  Direct Link  |  

Huang, Y.W., R.T. Lovell and R.A. Dunham, 1994. Carcass characteristics of channel and hybrid catfish and quality changes during refrigerated storage. J. Food Sci., 59: 64-66.
CrossRef  |  Direct Link  |  

Huss, H.H., 1981. Clostridium botulinum type E and botulism. M.Sc. Thesis, Technical University, Lyngby, Denmark.

ICMSF, 1986. Microorganisms in Foods 2: Sampling for Microbiological Analysis: Principles and Specific Applications. 2nd Edn., University of Toronto Press, Canada, ISBN-13: 978-0802056931, Pages: 448.

IS 2508, 1984. Specification for Low-Density Films. 2nd Edn., Bureau of Indian Standards, New Delhi.

Ishida, Y., T. Fuji and H. Kadota, 1976. Microbiological studies on salted fish stored at low temperature-I. Chemical and microbial changes of salted fish during storage. Bull. Jpn. Soc. Sci. Fish, 42: 351-358.
CrossRef  |  Direct Link  |  

Johnson, E.A., M. Peleg, F.M. Sawyer, R.A. Segars and A. Cardello, 1981. Mechanical methods of measuring textural characteristics of fish flesh. Refrigeration Sci. Technol., 4: 93-103.

Josephson, D.B., R.C. Lindsay and D.A. Stuiber, 1985. Effect of handling and packaging on the quality of frozen whitefish. J. Food Sci., 50: 1-4.
CrossRef  |  Direct Link  |  

Khan, M.A.A. and Y.S.A. Khan, 2001. Insects infestation and preventive measures in dry fish storage of Chittagong, Bangladesh. J. Biol. Sci., 1: 963-965.
CrossRef  |  Direct Link  |  

Kim, C.R., J.O. Hearnsberger, A.P. Vickery, C.H. White and D.L. Marshall, 1995. Extending shelf life of refrigerated catfish fillets using sodium acetate and monopotassium phosphate. J. Food Protect., 58: 644-647.
Direct Link  |  

Koutsoumanis, K. and G.J.E. Nychas, 1999. Chemical and sensory changes associated with microbial flora of mediterranean boque (Boops boops) stored aerobically at 0, 3, 7 and 10°C. Applied Environ. Microbiol., 65: 698-706.
Direct Link  |  

Lakshmanan, P.T., 2000. Fish Spoilage and Quality Assessment. In: Quality Assurance in Seafood Processing, Lyer, T.S.G., M.K. Kandoran, M. Thomas and P.T. Mathew (Eds.). Society of Fisheries Technologists, Cochin, India, pp: 26-40.

Lakshmanan, P.T., P.D. Antony and K. Gopakumar, 1996. Nucleotide degradation and quality changes in mullet (Liza corsula) and pearlspot (Etroplus suratensis) in ice and at ambient temperatures. Food Control, 7: 277-283.
CrossRef  |  Direct Link  |  

Lannelongue, M., M.O. Hanna, G. Finne, R. Nickelsen and C. Vanderzant, 1982. Storage characteristics of finfish fillets (Archosargus probatocephalus) packaged in modified gas atmospheres containing carbon dioxide. J. of Food Protect., 45: 440-444.
Direct Link  |  

Leung, C.K., Y.W. Huang and M.A. Harrison, 1992. Fate of Listeria monocytogenes and Aeromonas hydrophiia on packaged channel catfish fillets stored at 4°C. J. Food Protect., 55: 728-730.
Direct Link  |  

Lilly, T.Jr. and D.A. Kautter, 1990. Outgrowth of naturally occurring Clostridium botulinum in vacuum-packaged fresh fish. J. Assoc. Off. Anal. Chem., 73: 211-212.
PubMed  |  Direct Link  |  

Liston, J., 1957. The occurrence and distribution of bacterial types on flatfish. Microbiology, 16: 205-216.
CrossRef  |  PubMed  |  Direct Link  |  

Lyon, W.J. and C.S. Reddmann, 2000. Bacteria associated with processed crawfish and potential toxin production by Clostridium botulinum type E in vacuum packaged and aerobically packaged crawfish tails. J. Food Protect., 63: 1687-1696.
Direct Link  |  

McMeekin, T.A., L. Hulse and H.A. Bremner, 1982. Spoilage association of vacuum packed sand flathead (Platycephalus bassensis) fillets. Food Aust., 34: 278-282.
Direct Link  |  

Mezger, T.G., 2006. The Rheology Handbook: For Users of Rotational and Oscillatory Rheometers. Vincentz Network GmbH & Co. KG, Hannover, Germany, ISBN: 9783878701743, Pages: 299.

Nolan, N.L., J.A. Bowers and D.H. Kropf, 1989. Lipid oxidation and sensory analysis of cooked pork and turkey stored under modified atmospheres. J. Food Sci., 54: 846-849.
CrossRef  |  Direct Link  |  

Ogongo, O.B., O.P.M. Oduor and M.M. Nyale, 2015. Biochemical and nutritional quality of dried sardines using raised open solar rack dryers off Kenyan coast. J. Food Resour. Sci., 4: 33-42.
CrossRef  |  Direct Link  |  

Ozogul, F., A. Polat and Y. Ozogul, 2004. The effects of modified atmosphere packaging and vacuum packaging on chemical, sensory and microbiological changes of sardines (Sardina pilchardus). Food Chem., 85: 49-57.
CrossRef  |  Direct Link  |  

Ozogul, F., K.D.A. Taylor, P. Quantick and Y. Ozogul, 2000. Chemical, microbiological and sensory evaluation of Atlantic herring (Clupea harengus) stored in ice, modified atmosphere and vacuum pack. Food Chem., 71: 267-273.
CrossRef  |  Direct Link  |  

Parkin, K.L., M.J. Wells and W.D. Brown, 1982. Modified atmosphere storage of rockfish flllets. J. Food Sci., 47: 181-184.
CrossRef  |  Direct Link  |  

Rajesh, R., C.N. Ravi Shankar, T.K. Srinivasa Gopal and P.R.G. Varma, 2002. Effect of vacuum packaging and sodium acetate on the shelf life of seer fish during iced storage. Packaging Technol. Sci., 15: 241-245.
CrossRef  |  Direct Link  |  

Reddy, N.R., H.M. Solomon, H. Yep, M.G. Roman and E.J. Rhodehamel, 1997. Shelf life and toxin development by Clostridium botulinum during storage of modified-atmosphere-packaged fresh aquacultured salmon fillets. J. Food Protect., 60: 1055-1063.
Direct Link  |  

Reddy, N.R., H.M. Villanueva and D.A. Kautter, 1995. Shelf life of modified-atmosphere-packaged fresh tilapia fillets stored under refrigeration and temperature-abuse conditions. J. Food Protect., 58: 908-914.
Direct Link  |  

Sato, K., M. Ando, S. Kubota, K. Origasa and H. Kawase et al., 1997. Involvement of type V collagen in softening of fish muscle during short-term chilled storage. J. Agric. Food Chem., 45: 343-348.
CrossRef  |  Direct Link  |  

Savvaidis, I.N., P. Skandamis, K.A. Riganakos, N. Panagiotakis and M.G. Kontominas, 2002. Control of natural microbial flora and Listeria monocytogenes in vacuum-packaged trout at 4 and 10°C using irradiation. J. Food Protect., 65: 515-522.
PubMed  |  Direct Link  |  

Shalini, R., G.I. Jasmine, S.A. Shanmugam and K. Ramkumar, 2000. Sodium acetate and vacuum packaging to improve shelf life of refrigerated Lethrinus lentjan fillets. Fishery Technol., 37: 8-14.
Direct Link  |  

Sivertsvik, M., W.K. Jeksrud and J.T. Rosnes, 2002. A review of modified atmosphere packaging of fish and fishery products-significance of microbial growth, activities and safety. Int. J. Food Sci. Technol., 37: 107-127.
CrossRef  |  Direct Link  |  

Tarladgis, B.G., B.M. Watts, M.T. Younathan and L. Dugan Jr., 1960. A distillation method for the quantitative determination of malonaldehyde in rancid foods. J. Am. Oil Chem. Soc., 37: 44-48.
CrossRef  |  Direct Link  |  

Thybo, A.K. and M. Martens, 2000. Analysis of sensory assessors in texture profiling of potatoes by multivariate modelling. Food Qual. Preference, 11: 283-288.
CrossRef  |  Direct Link  |  

Tiffney, P. and A. Mills, 1982. Storage trials of controlled atmosphere packaged fish products. Technical Report No. 191, Sea Fish Industry Authority, October 1982.

USFDA., 1995. Bacteriological Analytical Manual. 8th Edn., United States Food and Drug Administration, USA.

Varga, S., R.A. Keith, P. Michalik, G.G. Sims and L.W. Regier, 1980. Stability of lean and fatty fish fillets in hypobaric storage. J. Food Sci., 45: 1487-1491.
CrossRef  |  Direct Link  |  

Zhuang, R.Y., Y.W. Huang and L.R. Beuchat, 1996. Quality changes during refrigerated storage of packaged shrimp and catfish fillets treated with sodium acetate, sodium lactate or propyl gallate. J. Food Sci., 61: 241-244.
CrossRef  |  Direct Link  |  

©  2019 Science Alert. All Rights Reserved
Fulltext PDF References Abstract