Moringa leaves have been considered as a valuable source of β-carotene, potassium, iron, calcium, protein and vitamin C1,2. The calcium content in Moringa oleifera is more than that in milk and the micro-nutrient content is more concentrated in dried leaves. About 17 times the calcium of milk, 9 time the protein of yoghurt3. Moringa has been found to be a good source of polyphenols and antioxidants.
Its reported to be anticancer activities, prevention of cardiovuscular diseases and liver diseases4. Moringa oleifera leaves considered as a safe supplement because it is not toxic. In the recent days Moringa has gained much importance to its multipurpose and benefits to industry and agriculture and it plays a role in fighting malnutrition some parts of Africa.
Mukunzi et al.5 reported that Moringa oleifera can be used to improve the nutritional and sensory evaluation of food by incorporating its extract into food products.
Furthermore, interest has grown in the utilization of Moringa oleifera in production of innovative foods by implementation of new product with cost reduction.
Several researches had been done to produce dairy products using dry leaves of Moringa oleifera suchas yoghurt6, labneh7, cottage cheese8 and soft cheese9.
The aim of this study is production of soft white cheese using Moringa oleifera dry leaves powder as a suitable functional ingredient for improving nutritional and sensory evaluation of soft white cheese.
MATERIALS AND METHODS
Fresh buffalos milk was obtained from the herd of the faculty of Agriculture, Cairo University, Giza.
Moringa oleifera leaves obtained from Moringa laboratory at National Research Centre. It contains 27-1/100 g protein, 2-3/100 g fat, moisture 7.5%, carbohydrate 38.2%/100 g and fiber 19.2/100 g.
Preparation of Moringa: Moringa leaves dried and made in powder by rubbing them over a sieve and the leaves powder stored in plastic container.
Preparation of soft white cheese: Buffaloes milk was divided into five portions.
First was applied as control and second, third, fourth and fifth were incorporating with 1, 1.5, 2 and 3%, respectively with Moringa leaves powder after coagulate; soft white cheese was manufactured according to Fahmi and Sharara10.
The resultant cheese was analyzed for chemically and organoleptically properties fresh and during cold storage at (5±1°C) for (2, 4 and 6 weeks).
Preliminary study: Resultant soft white cheese with different ratios of Moringa oleifra leaves (1, 1.5, 2 and 3%) were evaluated by apanel of staff members at dairy laboratory N.R.C. for sensory evaluation to choose best ratio. The best ratio was analyzed fresh and during cold storage at (5±1°C) for (2, 4 and 6 weeks).
Analytical methods: Total solids, soluble nitrogen, total protein were determined according to AOAC11. The pH values were measured using a digital laboratory pH meter (H1 93/400, Hanna instruments) with glass electrode. Total Volatile Fatty Acids (TVFA) content was determined according to Kosikowski12. Soluble tyrosine and tryptophan were determined according to Vakaleris and Price13, total amino acids according to Marino et al.14.
Colour change was measured using a spectrocolorimeter (Tristimulus color Machine) with CJE lab color scale (Hunter, lab scan XE-Restos VA, USA) in the reflection mode. The color was expressed in terms of L, a and b where, L value represents darkness from black (0) to white (100), a value represent yellow (+) to blue (-).
Sensory evaluation: Cheese samples were sensory evaluated by the method described by Scott15.
Statistical analysis: Statistical analysis was carried out using SAS16 software and probability of (p>0.05) was used to establish statistical significance.
RESULTS AND DISCUSSION
Table 1 shows thatcontrol had gained ahighest score for appearance, body and texture and flavour than other treatments followed by treatment with 1% of Moringa oliefera leaves powder. Finally with 2 and 3%, respectively. Preliminary study show that soft white cheese manufactured by 1% Moringa oliefera leaves powder was a best ratio and had a good appearance, body and texture and flavour than other treatments furthermore the best treatments was storage and analyzed chemically and organoleptically fresh and during cold storage.
Table 2 indicated that controls had a higher score than treatment for sensory evaluation during cold storage at 5±1°C.
|Table 1:|| Sensory evaluation of resultant cheese
|MOLP: Moringa oleifera leaves powder|
Sensory evaluation of soft white cheese manufacturing by using 1% Moringa oliefera leaves powder fresh and during cold storage at (5±1°C)
Dissimilar superscripts at the same row (for treatments) and the same column (for storage periods) are significantly differed (p>0.05)
Chemical composition changes of soft white cheese with Moringa oleifera
dry leaves fresh and during cold storage (5±1°C)
|Each value is a mean of 3 replicates (Table 2), Ts: Total solid, TP: Total protein, DM: Dry matter|
Scores for appearance gradually decreased during storage until 6 weeks. Also, body, texture and flavour took the same trend of appearance.
Statistical analysis shows that there is a significantly different between control and treatment fresh and during cold storage at p>0.05.
Figure 1 shows pH of soft white cheese with Moringa olifera dry leaves fresh and during cold storage. The pH is higher in control than treatment either fresh as during cold storage (5±1°C) .This may be due to the Moringa oleifera dry leaves. The pH gradually decreased during cold storage until 6 weeks either in control or treatment.
||pH of soft white cheese with Moringa oleifera dry leaves fresh and during cold storage at (5±1°C)
|Fig. 2:||Acidity of soft white cheese with Moringa oleifera dry leaves fresh and during cold storage at (5±1°C)
Acidity took an opposite trend of pH (Fig. 2). These results are in agreement to Hassan et al.6 and Salem et al.7.
Table 3 indicates total solids percentage of soft white cheese (control and treatment) fresh and during cold storage. Total solids are higher in treatment than control fresh and during cold storage. This may be due to the composition of Moringa oliefera dry leaves. Total solids increased gradually during storage until 6 weeks either control or treatment.
Total protein/dry matter and fat/dry matter are took the same trend of total solids either fresh as during cold storage until 6 weeks. These results are in agreement to Khalifa and Wahdan17. Statistical analysis shows that significantly differed between control and treatment and during cold storage at (5±1°C) at p>0.05 for total solids, total protein/dry matter and fat/dry matter.
Table 4 illustrate soluble nitrogen/total nitrogen (%), total volatile fatty acids as 0.1 mL of Na OH/100 g cheese, tyrosine and tryptophan mg/100 g cheese. It is clear that the best ratio (1%) had a higher soluble nitrogen/total nitrogen than control during cold storage.
The SN/TN percentage gradually increases during cold storage until 6 weeks in case of control and treatment.
||Soluble nitrogen/total nitrogen percentage, total volatile fatty acids, tyrosine and tryptophan of soft white cheese with Moringa oleifera dry leaves fresh and during cold storage at 5±1°C
|Each value is a mean of 3 replicates (Table 2), SN: Soluble nitrogen and TN: Total nitrogen
Colour changes of soft white cheese with Moringa oliefera leaves powder fresh and during storage period at 5±1°C
C: Control, T: Treatment, L*: Darkness from black (0) to white (100), a: Colour ranged from red (+) to green (-), b: Value represent yellow (+) to blue (-). Dissimilar subscribes at the same row (for treatments) and the same column (for storage periods) are significantly differed (p<0.05). Each value is a mean of 3 replicates
These results are in the same to Khalifa and Wahdan17 and Ismail et al.18 who reported that increasing soluble nitrogen throughout the ripening period may be due to the protein breakdown occurred by activities of microflora or proteolysis with proteolysis enzyme.
Table 4 shows total volatile content in control and treatment. Control had a lower content of TVFA than treatment in fresh and during cold storage. The TVFA increased gradually during cold storage until 6 weeks in both control and treatment. These results are in the same line with Abd El-Gawad19.
Table 4 shows that control had lower content of tyrosine (mg/100 g cheese) and tryptophan (mg/100 g cheese) than treatment fresh and during cold storage. Tyrosine and tryptophan gradually increased during cold storage until 6 weeks as a result of proteolysis.
These results are in agreement to Abd El-Gawad and Hassan20. Statistically analysis show that a significantly differed between control and treatment at (p>0.05) and during cold storage at 5±1°C for soluble nitrogen total nitrogen, total volatile fatty acids, tyrosine and tryptophan.
Table 5 shows colour change of control and treatment of soft white cheese. Control had a higher whiteness (L) than treatment either fresh or during cold storage at 5±1°C values of whiteness (L) gradually decreased during cold storage until 6 weeks.
These results were agreement to Hassan et al.6 who found that yoghurt manufactured by using 0.5% Moringa olifera leaves powder had a change of colour during cold storage. b represent yellow (+) to blue (-) had ahigher value in treatment than control. Values gradually increase during cold storage until 6 weeks. a represent colour ranged from red (+) to green (-) had ahigher value in control than treatment either fresh or during cold storage. Values of a gradually increased during cold storage at (5±1°C) until the end of storage. Saricoban and Yilmaz21 reported that change of colour in treatment which fortified with Moringa due to increase of dietary fiber of Moringa. Statistical analysis show that differences in L values between control and treatment significantly fresh and during cold storage at (p<0.05). Table 6 illustrate the amino acids content in soft white cheese manufacture with (1%) Moringa oleifera leaves powder. It is clear that soft white cheese had a highest content of glutamic acid (8.67%) followed by proline (4.05%) and leucine (3.75%) whereas it had a lowest content of methionine (0.99%), glycine (0.81%) and histidine (1.17%). Resultant cheese had a higher content of amino acids than that in leaves of dried Moringa.
Sanchez-Machado et al.22 reported that the variations in the amino acids composition could be influenced by protein quality and the origin of the plant (Cultivated or Wild). Also, it is shown that leucine in leaves having highest value of (0.75%) which is lower than our findings (1.97%).
Moringa leaves and resultant soft white cheese had 17 amino acids which is the same findings of Hassan et al.6 and differ from the findings of Foidl et al.23 and Sanchez-Machado et al.22 who reported 18 and 16 amino acids, respectively.
About 1% Moringa oleifera leaves powder was a suitable functional ingredient for improving nutritional and organoleptic properties of soft white cheese. Resultant soft white cheese was preferred and was more acceptable than control.
Moringa oleifera leaves powder led to increase the nutritional value of resultant cheese.