EVALUATION OF SELECTED TECHNOLOGICAL PARAMETERS FOR THE MANUFACTURE OF CHHASH
Loading...
Date
2003
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
AAU, Anand
Abstract
The present study was planned and conducted to evaluate certain technological parameters of Chhash manufacture. The experiment was divided into four phases. In the first phase, preliminary trials were conducted to screen various starter cultures (HST + LBW (1:1), MD2 + D3+ MD8 (1:1:1), MD2+ LBW (1:1), D3 + LBW (1:1), MD8 + LBW (1:1) and Wisbee) used for dahi making and Streptococcus thermophilus (HST) and Lactobacillus delbruckii sub sp.bulgaricus (LBW) in the ratio of 1:1 at a rate of 2.0% (v/v) of milk was found to give a good quality dahi. This was followed by selection of optimum level of TMS (5.0, 6.0 and 7.0%) and level of acidity (levels 0.5, 0.6 and 0.7% L.A.) in Chhash. For preparing Chhash, curd was stirred, mixed with equal amount of pasteurized water, heated to 60°C, homogenized at 100 Kg/cm2 and cooled to below 7°C. From the nine combinations tried, Chhash made with 7.0% TMS and 0.6% LA. was most preferred. During the second phase, selection of type and concentration of stabilizer, added to Chhash before thermal processing, for improving the body and texture characteristics and to prevent / minimize whey separation during processing and subsequent storage was attempted. From the stabilizers evaluated (viz. CMC, sodium alginate and guar gum all were employed at 0.05 and 0.1% (w/v) of Chhash), sodium alginate @0.05% was found to bring about significant improvement in the sensoric quality of Chhash followed by guar gum (0.05%), both were statistically at par. The stabilizers did not significantly affect the flavour of Chhash. The higher levels employed were found to affect body and texture score adversely. The preference order was observed as sodium alginate (0.05%) > guar gum (0.05%) > sodium alginate (0.1%) > guar gum (0.1%) > Control > CMC (0.05%) > CMC (0.1%). Chhash possessing viscosity in the range of 15 to 20 cP was preferred by the judging panel. Though, CMC provided viscosity in this range, the product was found to score less than the Control mainly because of slight coarse texture. In the third phase, heat treatment of Chhash was attempted by using batch as well as continuous method like HTST with a view to improve its shelf life. In the batch method Chhash was heated to 65°, 70° and 75°C for 5 min, while in HTST the same temperatures for 16 sec were tried; up stream homogenization was followed during this study. The Control (homogenized at 60°C and cooled immediately), and all experimental samples were stored at 37± 2°C and 7±1°C till their spoilage. During storage, a marginal increase in acidity and decrease in pH were observed in both samples of Chhash, which were heat treated either in batch or continuous method. The FFA content (μ equi. /ml) also tended to increase during storage. Both of these changes were found to proceed faster at the higher temperature of storage. The soluble nitrogen content (%) increased during storage, but the increase was found to proceed at a faster rate at lower temperature of storage, which may be attributed to the enzymes elaborated by surviving obligatory psychotrophs in Chhash. All the chemical changes were restricted by the thermal treatments employed and were minimum in case of Chhash thermally processed at 75°C for 5 min in case of batch method and 75°C for 16 sec in case of continuous method. Thermal treatment caused reduction in lactic count of 1.03 and 4.0 log cycles in case of Control and all experimental samples (Viz. CB65, CC65, CB70 CC70, CB75 and CC75) respectively. The reduction in SPC were 0.64, 1.97 (1.957), 1.98 (1.97) and 1.99 (1.99) log cycles respectively in Control, CB65 (CC65), CB70 (CC70), and CB75 (CC75). The lactic organisms and SPC were found to increase during storage and the rate of their growth was higher at the higher temperature of storage. The storage changes were foynd to be restricted by increasing the intensity of heat treatment. Yeast and mold were found to appear in Chhash during extended storage indicating post heat treatment contamination of the product, while the coliforms were observed to be absent in fresh as well as stored product. The shelf life of Control, CB65 (CC65), CB70 (CC70) and CB75 (CC75) stored at 37±2°C was found to be 2, 3, 4 and 5 days respectively. The corresponding values at 7+1 °C were 4, 8, 10 and 12 days respectively. The flavour and colour and appearance characteristics were affected during extended storage of the product. In the final phase of the experiment incorporation of whey. Cumin and common salt into Chhash were tried. Among the different whey types (i.e. Cheddar, Chhanna and Shrikhand whey) and levels (10, 20 and 30% (v/v) of dahi) tried, whey irrespective of its type up to a level of 20% (v/v) of dahi did not affect the sensory qualities of Chhash. However, Cheddar cheese whey preferred over other two types of whey. Cumin (Jira) was added in two different forms (roasted and non roasted form) at three different levels (0.3, 0.4 and 0.5% (w/v) of Chhash). Roasted Jira most preferred at a level of 0.4% (w/v). Salt was also tried at 0.3, 0.4 and 0.5% (w/v) of Chhash and 0.5% level improves the sensory characteristics (flavour) of Chhash. Further, Cumin and salt extended the storage life of CB75 (75°C for 5 min) by two more days i.e. 14 days against 12 days without Cumin and salt. The approximate cost of Chhash (CB75 with additives) was found to be Rs.0.92 per 200 ml sachet.
Description
Keywords
DAIRY TECHNOLOGY, DAIRYING, EVALUATION