Abstract: Dietetic and diabetic Rosogolla was manufactured by using low-fat cow milk. Twelve different combinations viz., type of chhana, cooking medium (double refined cane sugar syrup and sorbitol solution) and two different concentrations (40° and 50° Brix). All of the experimental samples and control samples were then analyzed for physico-chemical, textural and sensory properties. A 40° Brix concentration irrespective of the type of cooking medium was preferred to give a highly acceptable Rosogolla. The average composition of dietetic and diabetic Rosogolla is, moisture-49.83 and 52.20%, fat-4.66 and 4.46%, protein-11.85 and 12.78%, sucrose/sorbitol-32.41 and 29.66% and ash-0.90 and 0.89%, respectively. The hot Rosogolla of both types were packed in polyethylene terepthalate (PET) jars and stored for 40 days and 6 days at refrigerated (7±2°C) and room (26±2°C) temperature respectively. During storage pH of dietetic, diabetic and control Rosogolla, decreased, while free fatty acids, 5-hydroxy methyl furfural and soluble nitrogen content increased with the advancement of the storage irrespective of the storage temperature. Total viable count and yeast and mould count increased slowly in the samples stored at 7±2°C, but very sharply when stored at 26±2°C. Coliform count in both temperatures was observed to be zero.
INTRODUCTION
Indigenous dairy products have played an important role in socio-economic life of Indians since time immemorial and they account for over 90% of all dairy products consumed (Aneja et al., 2002; Singh et al., 2007). About 45 to 50% of milk produced in the country is converted into indigenous products and the consumption is likely to grow at an annual rate of more than 20% and the demand for Rosogolla may increase up to 6000 metric tones by the year 2009 (Mishra, 2000; Kumar et al., 2005). Traditionally, preparation of Rosogolla involves manufacturing of Chhana, a co-precipitate obtained by heat and acid precipitation of milk, kneading it into smooth paste, forming it into small balls of about 6 to 7 g each, cooking the balls in boiling sugar syrup (50 to 55° Brix) followed by its soaking in sugar syrup (35 to 40° Brix) for overnight. Various types of Rosogolla are available in the market viz., ordinary, sponge, canned and diabetic Rosogolla, which may be further classified as small, normal and large categories depending on size of balls and ingredients used. Diabetic Rosogolla is specially made for people who are suffering from diabetes. Here instead of sucrose, alcoholic sugar such as sorbitol is used (Adhikhari et al., 1992; Natarajan and Balachandran, 2006; Pal and Londhe, 2006; Karunaithy et al., 2007; Sachdeva and Reuter, 2007; Sahu and Jha, 2009; Bandyopadhyay et al., 2005, 2008). It is estimated that the raw material cost of Rosogolla is 33% of the sale price, while that for western dairy products are relatively much higher varying from 77 to 80% (Chandan et al., 2002). In India 29.66% people eat out frequently and about 48.14% of the population consumes high-fat diet (Chatterjee, 2007). This habit along with no exercise has created a situation in which every ninth individual is suspected for having cardiovascular diseases (CVD). It is estimated that the death caused due to CVD may rise to 40% by the year 2015. Rosogolla faces a problem of high sugar content (i.e., about 50%), as diabetic people cannot enjoy the sweet. Nonetheless, consumers who want the taste of sweetness without added energy may select non-nutritive sweeteners to assist in the management of weight, diabetes and CVD (Arora et al., 2006; George et al., 2006; Kroger et al., 2006). Hence for diabetic and health conscious consumers reformulation of Rosogolla is required. This offers an opportunity for the development and commercial manufacture of Dietetic and Diabetic Rosogolla that could fit easily into the dietary guidelines of diabetic and patients suffering from cardio vascular diseases. The present investigation was carried out with the objectives of studying the technological aspect of manufacture of Chhana from milk with a low-fat and evaluate their performance on quality of Rosogolla, effect of replacement of sucrose with Sorbitol and non-nutritive sweetener for cooking and or soaking purpose, physico-chemical and sensory characteristics and the cost effectiveness.
MATERIALS AND METHODS
The present investigation was carried out in the Department of Dairy Technology, S.M.C. College of Dairy Science, Anand in the year 2007-08. The fresh raw cow milk (4.5% fat, 8.5% MSNF and 0.16% acidity) was obtained from the Live Stock Research Station, Anand Agricultural University, Anand. Raw cow milk was preheated to 65°C and separated to obtain skim milk (0.1% fat, 8.9% MSNF and 0.17% acidity) for carrying out experimental trials. Raw cow milk and skim milk were filtered through muslin cloth and immediately pasteurized at 72°C for 15 sec and stored at 4°C for 2-3 h. Double refined cane sugar was obtained from the local market of Ahemdabad and sorbitol (70% liquid), was supplied by Darshan Chemicals, GIDC, Anand. Aspartame was procured from Nutrasweet-12 USA. PET jars were obtained from Anand market, which were sterilized using 100 ppm available chlorine solution.
Preparation of Chhana and Rosogolla
Experimental chhana and Rosogolla was prepared by the method
as shown in Fig. 1 which was modified from the methods as
reported by various scientists (Aneja et al., 2002;
Arora et al., 1996; Bandyopadhyay
et al., 2005) while Control Rosogolla (C) was prepared in
the same manner, except that the milk fat was standardized to 4% and coagulation
was carried out at 70 to 72°C. Three replications were carried out and chhana
made from milk containing 1, 2 and 3% milk fat were coded as F1,
F2 and F3 respectively. Rosogolla made from F1
chhana and cooked in Double Refined (DR) cane sugar syrup of 40 and 50°
concentration were coded as LF41 and LF51, respectively,
similarly when sorbitol was used as cooking medium they were coded as SF41
and SF51. In the same manner Rosogolla made from F2
chhana were coded as LF42 and LF52, SF42 and
SF52 when DR syrup and sorbitol were used as cooking medium.
| Fig. 1: | Flow diagram for preparation of diabetic and dietetic rosogolla |
Similarly, LF43 and LF53, SF43 and SF53 code were given for Rosogolla cooked in DR syrup and sorbitol made from F3 chhana. Dietetic Rosogolla (DTR) and Diabetic Rosogolla (DBR) were soaked in 40° Brix of DR cane sugar syrup and sorbitol added with 14.3 g aspartame, respectively.
Physico-Chemical Analysis
All the fresh and stored Rosogolla samples were subjected for physico-chemical
analysis by Indian Standards Institution (ISI: 4079, 1967),
textural, sensory evaluation and microbial count. 5-Hydroxy Methyl Furfural
(HMF) content was determined as suggested by Keeney and
Bassette (1959) and expressed as μmol/100 g. Free Fatty Acids (FFA)
content expressed as % oleic acid, was determined by the method suggested by
Deeth and Fitz-Gerald (1976). The soluble nitrogen (Soluble
N) content was determined by the procedure outlined by Kosikowski
(1982) and expressed as per cent. Total Viable Count (TVC) and coliform
count were determined by using the procedure as mentioned in ISI (IS 4079, 1967)
and yeast and mould as mentioned in by Indian Standards Institution
(ISI) (IS 5403, 1969). Yield (g L-1 of milk) of Rosogolla
was calculated by taking the difference of weight of Rosogolla after
soaking of the chhana ball.
Texture Analysis
Textural properties were determined using a Universal Testing Instrument,
Model-LRS Plus (Lloyd Instruments, England) equipped with a 50 N cell. Cylindrical
samples (20 mm diameter, 15 mm height) were drawn using a cork borer at 20°C
and were compressed at speed of 1 mm sec-1 upto 25% of its original
height.
Sensory Evaluation
Rosogolla samples were evaluated by a panel of five judges from Department
of Dairy Technology. The score card used for judging contained 45 marks for
body and texture, 35 marks for taste and smell and 20 marks for color and appearance.
Consumer Preference
A consumer preference study was carried out with DTR, DBR and market sample
(Haldiram Brand) by serving to 200 consumers, from three different places (i.e.,
100 from Anand and 50 each from Baroda and Nadiad), representing different segments
of society for their liking of Rosogolla. A nine-point Hedonic scale
was used for the preference study. In order to known the percentage of acceptance
regardless of age and place, the results obtained were arranged using a frequency
distribution technique.
Cost Estimation
Cost of Rosogolla was estimated upon the quantity obtained from 100
L of standardized milk (2% milk fat). Yield of DTR and DBR was 85 and 81 kg,
respectively.
Experimental Design
The data obtained during investigation was analyzed using Completely Randomized
Design (CRD), Factorial Completely Randomized Design (FCRD) (Steel
and Torrie, 1980).
RESULTS AND DISCUSSION
Physico-Chemical Characteristics of Rosogolla
The mean values for fat, protein, sugar (sucrose/sorbitol), ash and moisture
content are presented in Table 2.
Fat and Protein Content of Rosogolla
The average fat content of Rosogolla made from F1,
F2 and F3 chhana was 2.35, 4.75 and 6.81%, respectively
whereas; same Rosogolla had 16.41, 12 and 11.33% protein content (Table
1). An increasing trend in fat content and decrease in protein content of
Rosogolla was observed with the increasing fat content of milk used
for chhana making. The results obtained for the experimental samples are in
full agreement for good acceptability with those reported values of fat as 4.2
to 4.6% by Gangopadhyay et al. (2005) and Bandyopadhyay
et al. (2008), but in contradiction with those reported by Desai
et al. (1993). Minimum fat and protein level permitted by ISI (IS
4079, 1967) is 5.0% and it is observed that the values for LF42 and
SF42 Rosogolla are well below for fat and above for protein
content.
Moisture and Sucrose/Sorbitol Content of Rosogolla
The average moisture content of Rosogolla made from F1,
F2 and F3 chhana was 50.73, 52.69 and 43.60%, respectively.
For the same Rosogolla, sucrose/sorbitol content was 30.03, 29.62 and
36.61%, respectively (Table 1). The moisture content of C
was statistically lower as compared to LF52 and SF52 and
higher to those obtained from F3 chhana. The moisture and sucrose/sorbitol
content of all the experimental samples was well below the maximum level permitted
by ISI (IS 4079, 1967) which is 55 and 45%, respectively and in agreement with
those reported by Sahu and Jha (2009).
| Table 1: | Physico-chemical characteristics and yield of Rosogolla |
| NS: Non-significant | |
| Table 2: | Textural properties of Rosogolla |
| NS: Non-significant, Hard: Hardness, Coh: Cohesiveness, Spr: Kpringiness, Gum: Gumminess, Chew: Chewiness, Frac: Fracture force, Adhe: Adhesiveness, Stiff: Stiffness | |
Ash Content of Rosogolla
Use of 50° Brix concentrated cooking medium was found to give significantly
higher ash content in 40° Brix concentrated syrup (Table 1).
Ash content of all the samples was in full agreement with those reported by
Desai et al. (1993), Mathur
and Singh (2001) and Haque et al. (2003).
Yield of Rosogolla
Type of chhana had a significant effect on the yield of Rosogolla
(Table 1). Yield of Rosogolla made from F2
and CR chhana was significantly higher than F1 and F3
(Table 2). Yield of Rosogolla for all the experimental
samples were far lesser than 690 g L-1 of milk.
The interaction effect of FxM, FxL, MxL and FxMxL was found to be non-significant for all the physico-chemical properties but significant for yield. FxMxL showed a significant effect for protein content of Rosogolla.
Texture Analysis of Rosogolla
The quality of product is monitored not only by the sensory properties
but also by their rheological/textural profile.
Hardness
Hardness for C sample was significantly lower than all the experimental
Rosogolla samples which varied from 5.88 to 13.69 N. Type of chhana had
a significant effect while an increasing trend was observed with the increasing
fat content of milk used for chhana making (Table 2).
Cohesiveness
The cohesiveness of control Rosogolla was found to be at par with
those of experimental Rosogolla which varied from 0.41 to 0.61 (Table
2). Rosogolla made from F1 chhana had higher cohesiveness
value followed by F2 and F3 (Table 2).
According to report available the results were well in accordance with those
reported by Desai et al. (1993) and Patil
(2002).
Springiness
Springiness of all experimental samples varied from (5.36 to 6.06 mm) and
non-significantly different from that of Control (Table 2).
The springiness of Rosogolla made from F1 and F2
chhana was higher than those Rosogolla made from F3 but lower
than Control Rosogolla (Table 2). The results were
as like that of Control sample and were well above 3.82 to 5.0 mm as reported
by Adhikhari et al. (1992), Patil
(2002), Bandyopadhyay et al. (2005, 2008)
and Karunanithy et al. (2006).
Gumminess
It can be seen from Table 2, that the treatments applied
had shown a significant effect on gumminess of Rosogolla. The value of
gumminess for Control sample was 2.5 N, which was significantly lower than (LF51,
SF41, LF52, SF42, SF52, DF43,
SF43 and SF53) the experimental Rosogolla samples
and in accordance within the range 2.98 to 4.69 N reported by Desai
et al. (1993), 3.62 N by Adhikhari et al.
(1992).
Chewiness
Chewiness of experimental samples varied from 18.92 to 29.75 Nmm and was
significantly higher than control Rosogolla (Table 2).
The recorded values were higher than the values (5.80 to 18.00 Nmm) reported
by Adhikhari et al. (1992), Patil
(2002) and Karunanithy et al. (2006). The
possible reason for higher chewiness might be the high moisture and protein
and low fat content.
Fracture Force
The value of fracture force was affected by the treatments applied (Table 2). An increasing trend in fracture force, with the increase in fat content of milk from 2 to 3% used for chhana making was observed.
Adhesiveness
From the Table 2, it is clear that adhesiveness of Rosogolla
was significantly affected by the type of chhana and Rosogolla made from
F1, F2 and F3 chhana had significantly lower
adhesiveness than the Control (Table 2).
Stiffness
The value of stiffness of all the experimental Rosogolla samples
were significantly higher than control sample (Table 2).
The interaction effect of FxL, MxL and FxMxL were found to give a significant effect on hardness, fracture force of Rosogolla. In case of gumminess is only significant for MxL while adhesiveness is only significant for FxL, FxMxL. None of the interactions significantly affected the cohesiveness, springiness and chewiness of Rosogolla.
Sensory Evaluation of Rosogolla
Body and Texture Score
A non-significant effect of the treatment applied during making of experimental
Rosogolla was observed (Table 3). The Control sample
scored an average of 39.05, which was higher than experimental sample (except
LF42 and LF43).
| Table 3: | Sensory evaluation of Rosogolla$ |
| $Average of three replications, NS: Non-significant | |
Taste and Smell Score
It can be seen from Table 3, that the treatments showed
a significant effect and the score of control was statistically similar to all
of the experimental Rosogolla samples and SF43 scored the
lowest amongst all.
Color and Appearance Score
Cooking of chhana balls markedly alters the color and appearance of the
Rosogolla. All of the experimental Rosogolla and were statistically
similar to Control Rosogolla except SF41 and SF43
(Table 3).
Overall Acceptability
The overall acceptability score of Rosogolla was found to be influenced
significantly by the treatments given during the study (Table
3). Overall acceptability scores experimental Rosogolla varied from
71.38 to 91.38 and except SF41 all were statistically at par with
Control.
From the results delineated in Table 3, it is evident that the interaction effect of MxL caused a significant effect on all the sensory properties except body and texture. Similarly, the interaction effect of FxM, FxL and FxMxL was found to be non-significant.
Changes in Physico-Chemical Properties of Rosogolla During Storage pH
The change in pH of Rosogolla are depicted in Table
4. The pH of DTR and Control are higher than the pH of DBR during all storage
period at both temperature as reported by Arora et al.
(1995, 1996) and Singh et
al. (2007).
Free Fatty Acids (FFA)
The FFA content of DTR and Control are higher than the FFA of DBR irrespective
of storage temperature at all storage periods (Table 4). Such
an increase has also been reported by Arora et al.
(1995, 1996) and Singh et
al. (2007). The interaction effect of TXP was found significant (p≤0.05).
5-Hydroxymethyl Furfural (HMF)
HMF content of all the samples irrespective of storage temperature and type
was found to increase with duration of storage (Table 5).
The observations are well supported by the findings of Arora
et al. (1995, 1996) and Singh
et al. (2007).
| Table 4: | Influence of treatment and storage period on pH and FFA (% oleic acid) of Rosogolla |
| P: Storage period, -: Days, DTR: Dietetic Rosogolla, DBR: Diabetic Rosogolla, NS: Non-significant | |
The increase in HMF content was in order C>DTR>DBR after 40 days and DTR>C>DBR after 6 days of storage at 7±2°C and 26±2°C, respectively.
Soluble Nitrogen (Soluble N)
The soluble N content was found to increase with increase in storage period
irrespective of storage temperature and type (Table 5). The
results are in conjunction with the observations made by Arora
et al. (1995, 1996) and Singh
et al. (2007). The interaction effect of (TXP) for storage at refrigeration
temperature was found to be significant (p≤0.05), while non-significant in
the case of room temperature storage.
Effect of Storage on Sensory Attributes of Rosogolla
Body and Texture Score
The body and texture scores of Rosogolla declined with the advancement
of storage period regardless whether it was stored at refrigeration or room
temperature (Table 6). The keeping quality wise the product
followed pattern of DTR>DBR>C for storage at 7±2°C and 26±2°C.
| Table 5: | Influence of treatment and storage period on HMF (μmol/100 g) and soluble N (%) of Rosogolla |
| P: Storage period, -: Days, DTR: Dietetic Rosogolla, DBR: Diabetic Rosogolla, NS: Non-significant, S.N: Soluble N | |
| Table 6: | Influence of treatment and storage period on body and texture and taste and smell |
| P: Storage period, -: Days; DTR: Dietetic, Rosogolla DBR: Diabetic Rosogolla NS: Non-significant; B and T: Body and Texture, T and S: Taste and Smell | |
Taste and Smell Score
During storage, Rosogolla undergoes various physico-chemical and
microbial changes which tends to affect the taste and smell of the product.
The taste and smell score of Rosogolla during storage, regardless of
temperature decreased (Table 6).
Color and Appearance Score
DTR, DBR and C Rosogolla were found to score more than 60% marks
for (i.e., 12.00 out of 20) and were acceptable on 40th day of storage but in
case of those stored at 26±2°C scored below rejection point after
6 days (Table 7).
Overall Acceptability
The overall acceptability score decreased with the increase in storage,
regardless of temperature (Table 7). DTR and DBR scored well
above the rejection point (60.00 out of 100) after 40 days of storage. While
all the samples stored at 26±2°C failed to score above the rejection
point.
Changes in Microbiological Quality of Rosogolla During Storage
Total Viable Count (TVC)
Total viable count at both refrigeration and room temperature were found
to increase with the increase in storage period (Table 8).
Such increase in TVC is also reported by Singh et al.
(2007), but was in contrast with those reported by Arora
et al. (1995, 1996).
Yeast and Mould Count
The yeast and mould count of Rosogolla during storage increased with
the progress of storage (Table 8). DTR, DBR and C Rosogolla
were free from yeast and mould up to 10 days of storage at 26±2°C
but were apparent after further storage. Such increase in yeast and mould was
also reported by Singh et al. (2007).
Coliform Count
Rosogolla samples stored at 7±2 and 26±2°C temperature
were found to be free from coliform at the end of 40 days and 6 days of storage.
The interaction effect of (TXP) for storage at 7±2°C was found to be significant for increase in TVC and yeast and mould count.
| Table 7: | Influence of treatment and storage period on color and appearance score and overall acceptability of Rosogolla |
| P: Storage period, -: Days, DTR: Dietetic Rosogolla, DBR: Diabetic Rosogolla, NS: Non-significant, C and A: Colour and Appearance, OA: Overall acceptability | |
| Table 8: | Influence of treatment and storage period on total viable count and yeast and mould (log cfu g-1) of Rosogolla |
| $: Average of three replications, P: Storage period, -: Days, NS: Non-significant, TVC: Total Viable Count, Y and M: Yeast and Mould | |
| Table 9: | Estimated cost of production of dietetic Rosogolla (DTR), diabetic Rosogolla (DBR) and control Rosogolla |
Cost Estimation
The total production cost was found to be Rs. 4250 and Rs. 2993 for LFSR
and LFDR respectively (Table 9). The raw material cost constitutes
88.12 and 83.79% of product cost for LFSR and LFDR, respectively. The packaging
and processing cost for both the Rosogolla constitutes 11.88 and 16.21%,
respectively. Cost of production of Control Rosogolla was Rs. 38 per
kg.
CONCLUSION
Dietetic and diabetic Rosogolla with acceptable quality can be prepared using chhana made from cow milk standardized to 2% milk fat. Chhana can be prepared by coagulating at 60°C, employing 1% citric acid maintained at same temperature and a final pH 5.4, followed by straining. Well kneaded chhana balls can be cooked and soaked at 40° Brix double refined sugar solution to obtain dietetic Rosogolla. Whereas, 40° Brix Sorbitol solution is required for cooking of diabetic Rosogolla followed by soaking in 40° Brix sorbitol solution containing 14.3 g L-1 aspartame. When packed in polyethylene terepthalate jars and stored at refrigeration temperature they gave a shelf-life of more than 40 days and not more than 6 days at room temperature. Acceptance of dietetic and diabetic Rosogolla decreased with increase in storage period which might due various physico-chemical and microbial change, affecting the textural and thereby the organoleptical properties. The cost of DTR and DBR is Rs. 50/- and Rs. 37/, respectively. The cost of DTR was less by Rs. 1/-, while that of DBR was more by Rs. 12/- as compared to control Rosogolla (Rs. 38 kg-1).