Development of mathematical model for prediction of adulteration levels of cow ghee with vegetable fat using image analysis.

The present study was undertaken to develop a protocol for acquisition and analysis of images of ghee samples to derive mathematical parameters related to adulteration of cow ghee with vegetable fat and to develop a model to predict the adulteration levels. The images acquired using a flatbed scanner were quantified in terms of their pixel intensity, colour, morphological, textural and skeleton parameters using ImageJ software. The selected parameters were measured for images of pure cow ghee and compared with that obtained for ghee adulterated with 5%, 10%, 15% and 20% vegetable fat. The parameters were assessed for their ability to detect the fixed adulteration levels on a discrete scale was assessed using discriminant analysis and the adulteration levels of the samples were correctly classified to the extent of 92.2%. An equation for predicting adulteration levels on a continuous scale using regression analysis (adjusted R 2 value 0.94) was developed, tested and further validated using a fresh data set including a commercially popular market sample of ghee giving a good fit (R 2 value of 0.85).

Quality attributes of dahi prepared from milk fortified with omega-3 fatty acids, phytosterols and polydetxrose.

In the present study, dahi prepared using milk fortified with omega-3 fatty acids (flaxseed oil), phytosterols and soluble fibre (polydextrose) through an oil-in-water emulsion was evaluated for the physico-chemical and sensory quality. The levels of fortificants in fortified dahi were also estimated. Fortification process did not affect the degree of fermentation in terms of pH and acidity. Sensory scores of fortified and control dahi did not differ significantly. Fortified dahi had lower viscosity, firmness and consistency, and higher water holding capacity (WHC) compared to control; however, significant differences were not observed in firmness and consistency values. Storage study indicated that pH, acidity, %WHC, firmness and consistency values and lactic acid bacterial counts did not differ significantly throughout storage period in both the dahi samples and recorded good sensory acceptability during storage. Fortified dahi provides 282.53 mg, 415.92 mg and 1.019 g of α-linolenic acid, total phytosterols and polydextrose, respectively per 100 g of product. Moreover, no loss in the initial content of ALA, phytosterols and polydextrose had occurred after 8 days of storage period. The present study suggests the feasibility of adding flaxseed oil, phytosterols and polydextrose as functional ingredients in the form of water soluble emulsion to milk, which could be converted to dahi with acceptable properties and enhanced nutritional and therapeutic potency.

Effect of flaxseed oil and flour on sensory, physicochemical and fatty acid profile of the fruit yoghurt.

The objective of this study was to incorporate flaxseed oil, flaxseed flour and fruits for the preparation of fruit yoghurt and analysed for their sensory, physicochemical and fatty acid profile. Overall acceptability of sensory scores indicates that fruit yoghurt (20% fruit and sugar mixture) with incorporation of flaxseed oil up to 2% and flaxseed flour up to 1% in combination can be used for preparation of fruit yoghurt with acceptable sensory attributes. The scores drastically reduced for yoghurt samples wherein 2% flaxseed flour was incorporated. The mixture of sugar and fruits diluted the milk composition and resulted in lower values in the fruit yoghurts. The increase in fat, protein, carbohydrate, minerals content in the yoghurt was mainly contributed by the flaxseed oil and flour. The addition of flaxseed oil did not show any affect on the water activity of the yoghurt samples. The yoghurt had dietary fiber content of 1.24%. The fresh control fruit yoghurt showed the acidity value of 0.88% LA, while the corresponding value for experimental samples varied between 0.85 and 0.88% LA. TBA values increased with increased incorporation of flaxseed oil and flaxseed flour. The fatty acid analysis revealed that alpha linolenic acid (ALA) content increased from 0.45% of ALA in control sample to 22.80% of ALA in the final product.

Cultural conditions for the production of bacteriocin by a native isolate of Lactobacillus delbruecki ssp. bulgaricus CFR 2028 in milk medium.

The effect of growth parameters and the molecular basis for antibacterial activity by a natural isolate of Lactobacillus delbruecki ssp. bulgaricus CFR 2028 was studied. The inhibition was tested against a toxigenic strain of Bacillus cereus F 4810. When grown in milk medium, the activity was highest at an incubation temperature of 37 degrees C in 48 h. The antibacterial activity appeared to be produced between late logarithmic and early stationary phases. The active principle was proteinaceous in nature (bacteriocin) and stable to low pH (3.8-5.0) and heat (75 degrees C for 30 min). There was also the possible role of hydrogen peroxide in bringing about inhibition. The strain of Lact. delbruecki ssp. bulgaricus CFR 2028 revealed the presence of plasmid DNA bands of 9.4 and 6.5 kbp, respectively, in agarose gel electrophoresis. The above strain has the potential to be used as a biopreservative in popular Indian fermented foods.