Phenotypic and genotypic characterisation of Lactobacilli isolated from camel cheese produced in India

Thirty‐two Lactobacilli strains were isolated from four samples of camel cheese collected from Bikaner, India. These isolates were identified based on phenotypic and genotypic characteristics. Sequencing of 16S rDNA was performed for species identification and diversity analysis. Lactobacillus delbrueckii and Lb. fermentum were found to be dominant species followed by Lb. plantarum and Lb. casei. On evaluation of technological properties of these isolates, 20 isolates were observed to be good acid producers, eight were found positive for citrate utilisation and 11 showed presence of Prtp gene. Isolates obtained can be potential for development of defined strain starter for camel cheese.     

Ionizing Radiation Effects on Starch as Shown by Staudinger Index and Differential Thermal Analysis

SUMMARY— Corn starch in the form of raw granules at commercial moisture was irradiated at two levels: 3 × 10⁵ and 6 × 10⁶ rad from a Co⁶⁰ source. The irradiated samples were completely dissolved in alkali, indicating there was no cross linking induced in the starch molecules by irradiation. Viscosity determinations of starch solution diluted with distilled water exhibited the ion charge effect generally observed in other macromolecules.
The Staudinger indices of unirradiated, irradiated at 3 × 10⁶ rad and 6 × 10⁶ rad were 42, 22 and 16 respectively, which were an indication of depolymerization of starch macromolecules with increasing irradiation. The differential thermal analysis of the three samples also showed the depolymerization of the polymer with irradiation.
It is suggested that these two simple techniques–the Staudinger index and D.T.A.–could be usefully employed to characterize small differences in starches.     

Nutritional Evaluation of Accelerated Ripened Cheddar Processed Cheese

Accelerated ripened Cheddar cheese was prepared by blending two parts of shredded curd made from standardized cow's milk with one part of 5.2% NaCl solution and ripening at 30°C for 8 days. On a dry matter basis, protein and fat of accelerated ripened cheese were similar to that of conventionally ripened Cheddar cheese, while lactose and total ash were greater. Similar observation was made for processed cheese samples. No change in vitamin A or in riboflavin but a fourfold increase in folic acid was observed during accelerated ripening. Protein efficiency ratio, net protein utilization and digestibility coefficient by rat tests were slightly but significantly higher for conventionally ripened processed cheese. However, no difference in biological value was observed.     

Estimation of sugars in milk by HPLC and its application in detection of adulteration of milk with soymilk

A high-performance liquid chromatography method is described for the detection of adulteration of milk with soymilk, based on separation of sugars on NH₂ column and their detection by refractive index detector. Sugars were extracted with 20% acetonitrile in the presence of Carrez solutions and quantified. Recovery of added raffinose to soymilk was 96.3%. Owing to relative high concentration of lactose in milk or adulterated milk, lactose peak was very broad and spread to retention time corresponding to sucrose and raffinose. However, stachyose peak remained well separated. Presence of stachyose peak in milk can be used for the detection of adulteration of milk with soymilk and the method can detect upto 5% soymilk in milk.     

A COMPUTATIONAL ALGORITHM FOR THE SENSITIVITY ANALYSIS OF POSYNOMIAL AND SIGNOMIAL GEOMETRIC PROGRAMMING PROBLEMS

In this paper we present a computational algorithm which can be used to carry out the sensitivity analysis of posynomial and signomial geometric programming problems, both for changes in the values of the cost coefficients and for changes in the values of the exponents of the unknown variables. Computational experience of using this algorithm to study the sensitivity analysis of some test examples is also presented.     

Studies on physicochemical and antioxidant properties of strawberry polyphenol extract–fortified stirred Dahi

The addition of bioactive polyphenolic compounds to dairy products is linked to improve their antioxidant potential. The aim of the present investigation was to evaluate the effect of strawberry polyphenol on physicochemical properties, total phenolic and antioxidant activity of stirred dahi. Strawberry polyphenol extract was used to fortify stirred dahi (0.5 mg/mL). This fortification resulted in a sevenfold increase in the antioxidant activity of polyphenol‐enriched stirred dahi, while pH, acidity, water‐holding capacity and viscosity remained comparable with the control. Sensory analysis indicated that the product was acceptable up to 2 weeks when stored at 7–8 °C with no significant difference (P > 0.05) in the antioxidant activity and total phenolic content.