K. Jayaraj Rao

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.

Correlations among instrumental textural characteristics, sensory score and solids content of Dahi – An Indian fermented milk product

The relationship among total solids content, textural and sensory parameters of dahi was investigated and reported here. The total solids (TS) content of fresh skim milk was adjusted to 9, 12, 15, 18, 21 and 24% using spray dried-skim milk powder. Dahi was prepared from these milks with adjusted TS and were chilled to 5°C. Firmness, consistency and viscosity index of dahi samples, measured by texture analyzer, showed a general increasing trend with increasing %TS in milk. Sensory scores were the highest at 15% TS. The TS content, texture and sensory quality were interdependent and instrumental texture parameters highly influenced the sensory scores. By univariate analysis, sensory score showed a linear relation with consistency and firmness exhibiting low RMS values. Relationships were much better with multivariate analysis as indicated by multiple regression involving consistency, firmness, viscosity index and their products indicating that the sensory acceptance of dahi is dependent on more than one textural parameter.