Physico-chemical and color parameters to distinguish cow ghee from buffalo ghee.

Ghee production form one of the largest segments of the milk consumption and utilization pattern in India. Recently, cow ghee has become more popular and fetching premium over buffalo ghee as there are innumerable health benefits credit to cow ghee since they contain an important array of nutrients and therapeutic principles. Therefore, the present investigation was conducted to differentiate and characterize cow ghee from buffalo ghee using physico-chemical parameters viz. BR reading, RM value, Polenske value, Kirschner value and different color values. Pure cow and buffalo ghee samples were prepared using creamery butter method. Pure ghee samples (cow and buffalo) and cow ghee samples admixed with buffalo ghee @ 5%, 10%, 15% and 20% were analyzed for above mentioned physico-chemical parameters and different color parameters. The results revealed that BR reading, RM value, Polenske value and Kirschner value of pure cow ghee ranged from 41.87-43.62, 27.5-31.13, 1.30-1.90 and 20.74-24.14 and in buffalo ghee these values ranged from 40.01-43.23, 31.91-39.99, 1.10-1.50 and 26.84-33.96, respectively. The color values i.e. lightness (L), redness(a), yellowness (b), yellowness index (Y) and whiteness index (W) of pure cow ghee ranged from 70.17-81.56, - 14.04 to - 28.96, 59.68-79.31, 74.25-88.92 and 16.07-28.85 and of buffalo ghee ranged from 71.89-83.71, - 1.07 to - 11.92, 1.39-9.61, 5.21-22.46 and 68.74-84.61. BR reading, RM value, Polenske value and L, a, b and Y of cow ghee adulterated with buffalo ghee up to 20% falls within the range of different pure cow ghee samples but whiteness index (W) and Kirschner value of admixed cow ghee (23.91 and 34.86) were having significantly higher values than the pure cow ghee (21.07 and 25.45, respectively). Kirschner Value and whiteness index (W) can be used to distinguish cow ghee from buffalo ghee.

Colouring properties and stability of black carrot anthocyanins in yoghurt.

Among the natural pigments anthocyanins have potential to be applied as natural colourants besides exhibiting wide range of bioactivity. Colouring potential and storage stability of black carrot concentrate (BCC) containing anthocyanins in yoghurt was determined in present investigation. The instrumental colour (CIELAB) values were altered by the addition of BCC in yoghurt in which the L* and b* values decreased, while a* value increased with increasing levels of BCC. Maximum sensory scores were observed for yoghurt with 1.5% BCC, as it was similar to strawberry in colour and appearance. Enhancement in the total anthocyanin, total phenolics and DPPH antioxidant activity was observed with increasing levels of BCC in yoghurt. L* value remained same during storage in both yoghurts, but a* value increased slightly. Similar trend was also noticed in BCC yoghurt for anthocyanins and antioxidant activity. The total phenolic content got enhanced in control, but decreased significantly in BCC yoghurt. Sensory evaluation revealed that scores decreased during storage but the product was acceptable up to 15 days. Our study further confirmed that higher stability and better colouring properties of black carrot concentrate in fermented milk system was due to higher degree of acylation.

Application of image analysis technique to determine cleaning of ohmic heating system for milk.

Cleaning of equipment is one of the major areas of concern in food industry. Image analysis technique was used to assess the cleaning effectiveness and optimize the CIP protocol for ohmic heating setup. Process parameters selected for optimization of cleaning were caustic concentration (1.0, 1.5, 2.0 and 2.5%), caustic temperature (70, 75, 80 and 85 °C), acid concentration (0.00, 0.25, 0.5 and 0.75%), and acid temperature (40, 50, 60 and 70 °C). Time for caustic treatment was varied from 5 to 20 min at an interval of 5 min, while time acid treatment was kept at a constant of 10 min. Taguchi orthogonal array design was used generate different combinations of acid and alkali concentration and temperature. Images of ohmic heating plates were taken before and after the cleaning procedure. MATLAB program was developed to analyze and extract Gray-Level Co-occurrence (GLCM) matrix properties from the image. Optimized combination was selected based on the highest value of desirability factor among all the experimental set of trials. Treatment with 1.5% caustic concentration at 70 °C for 5 min followed by 0.5% nitric acid concentration at 60 °C was found optimum effective CIP of the heating plates used in ohmic heating setup. GLCM properties correlation, cluster prominence, cluster shade, entropy, homogeneity and inverse difference moment normalized were found suitable for analysis of cleaning effectiveness and optimization of the CIP protocol.