Fig. 3.1 Ultrafiltration Plant

proved to be the most useful parameter for the characterization of whitening ability. The L* a* b* value in coffee were 52.19, 4.12 and 19.32 for standardized LFDW, 49.61, 5.01 and 17.85 for LFDW and 44.79, 7.83 and 26.35 for market sample respectively, having equal total solid (3%) content as shown in (Table 4.8). In terms of whiteness standardized LFDW found significantly superior (P<0.01) than LFDW and market sample in coffee. Standardized LFDW exhibited more whiteness which was undesirable in coffee (Fig. 4.9). Table 4.8: Whitening ability of LFDW with and without simplesse in coffee S (2%) LFDW MS CD Value L* 52.21 a 49.61 c 44.79 c 0.17** a* 4.12 c 5.01 b 7.83 a 0.29** b* 19.32 b 17.85 c 26.35 a 0.33** abcd Different letters within the same row indicate significantly different means; Values with same letters are statistically at par with each others ** significant at p<0.01 4.9 EFFECT OF DIFFERENT LEVEL OF MILK SOLIDS ON SENSORY CHARACTERISTICS OF STANDARDIZED LFDW IN COFFEE Standardized LFDW exhibited more whiteness. To overcome this problem standardized LFDW was evaluated for sensory attributes at different levels (3%, 2.5% and 2.0%) of milk solids (MS) added to coffee concoction (Table 4.9 and Fig. 4.10). Aim of the study was to explore the possibility of decreasing the whiteness. Study demonstrated that in terms of sensory attributes like flavour, mouthfeel, whiteness and overall acceptability 2.5% MS level found significanty better (p<0.05) than other two levels in coffee.the most intense effect was on whiteness as revealed by judges. 2.5% MS level was observed to be optimum by judges in coffee. Hence the optimized level of milk solids to be added to coffee was 2.5%. 69

Table 4.9: Effect of different level of milk solids on sensory characteristics of standardized LFDW in coffee DW (2%) DW (2.5%) DW (3%) CD Value Flavor 6.75 c 7.83 a 7.08 b 0.521* Mouthfeel 6.75 c 8.17 a 7.5 b 0.595* Whiteness 6.75 c 7.25 b 7.58 a 0.988* Appearance 7.17 7.83 7.33 0.837 Sweetness 7.17 a 7.33 a 7.01 b 0.235* Overall Acceptability 6.83 b 7.58 a 7.08 b 0.424* abcd Different letters within the same row indicate significantly different means; Values with same letters are statistically at par with each others * significant at p<0.05 4.10 WHITENING ABILITY OF STANDARDISED LFDW AT DIFFERENT LEVELS IN COFFEE Standardized LFDW and LFDW were analyzed for colour parameters i.e. L*, a*, b* values using Hunter Lab tristimulus spectrophotometer and were compared in coffee concoction with market sample at 3% 2.5% 2% level of MS (Table 4.10 and Fig. 4.11). Table 4.10: Whitening ability of standardised LFDW at different levels in coffee LFDW 3% LFDW 2.5% LFDW 2% CD Value L* 51.45 a 47.87 b 45.02 c 0.91** a* 5.02 5.22 5.05 0.96 b* 18.96 19.40 19.89 0.70 abcd Different letters within the same row indicate significantly different means; Values with same letters are statistically at par with each others ** significant at p<0.05 70

9 8 7 6 5 4 DW (2%) DW (2.5%) DW (3%) Sensory Score 3 2 1 Flavor Mouthfeel Whiteness Appearance Sweetness O A Fig. 4.10: Effect of different level of milk solids on sensory characteristics of standardized LFDW in coffee 71

60 55 50 45 40 35 30 25 20 15 10 5 0 L* a* b* Fig. 4.11: Whitening ability of standardised LFDW at different levels in coffee 72 LFDW 3% LFDW 2.5% LFDW 2%

The L* a* b* value in coffee are 51.45, 5.02 and 18.96 for 3% MS, 47.87, 5.22 and 19.40 for 2.5% MS and 45.02, 5.05 and 19.89 for 2% MS. LFDW with 3% of MS showed over whiteness which was undesirable in coffee. 2.5% MS level, imparted significantly (P<0.01) better whitening ability as compare with other samples in coffee. This led to the possibility of saving 0.5% MS per cup of coffee as compared to market sample. 4.11 SENSORY CHARACTERISTICS OF STANDARDIZED LFDW IN TEA Standardized LFDW was evaluated for various sensory attributes with respect to market sample in tea. The scores are given in Table 4.11.In terms of flavour market sample displayed significantly superior score (P<0.05) than standardized LFDW but standardized LFDW showed highest overall acceptability as compared with LFDW and market sample as shown in fig 4.12 Table 4.11: Sensory Characteristics of standardized LFDW in tea LFDW LFDW+S 2% MS CD Value Flavor 6.92 b 7.42 a 7.58 a 0.43* Mouthfeel 6.67 b 7.50 a 7.42 a 0.66* Whiteness 7.33 b 7.75 a 6.92 b 0.37* Appearance 7.75 a 7.83 a 7.17 b 0.55* Sweetness 7.17 7.08 7.08 0.40 Overall Acceptability 6.67 b 7.67 a 7.33 a 1.03* abcd Different letters within the same row indicate significantly different means; Values with same letters are statistically at par with each others * significant at p<0.05 4.12 WHITENING ABILITY OF STANDARDIZED LFDW IN TEA Standardized LFDW and LFDW were analyzed for colour parameters i.e. L*, a*, b* values using Hunter Lab tristimulus spectrophotometer and were compared in tea with market sample at 3% level of MS (Fig. 4.13). The L* a* b* value in tea were 46.24, 9.64 and 23.13 for standardized LFDW, 44.1, 8.68 and 22.86 for LFDW, 42.62, 8.72 and 23.62 for market sample respectively, having same total solid (3%). Standardized LFDW showed significantly more whiteness (P<0.01) than LFDW and market sample. 73