Biochemical parameter
During the 90 days of the storage period, the biochemical parameters of papaya-tomato blend chutney differed significantly in each treatment, as shown in Table 1. TSS, Acid: Brix ratio, Total sugars and reducing sugars were increased. At the same time, Titratable acidity and Ascorbic acid decreased significantly.
The TSS of the chutney has increased throughout the storage period from 2.78 -7.37%. A higher per cent of the increase was observed in T2 (95: 05) with 7.37% and a lesser increment was observed in T7 (50:50) with 2.78%. The increase in TSS is because of the hydroxylation of the polysaccharides into the monosaccharide and soluble disaccharides, or because of the conversion of starch and other insoluble carbohydrates into sugars
(Luh and Woodroof, 1975). A similar trend of TSS was found in other research, like in aonla-papaya chutney
(Sachin. 2017). However, in the case of acidity, the trend decreased from the range of 23.91-7.25%. Here higher tomato pulp contributed to the higher acidic level in each treatment. A maximum of 23.91% decrease is found in T2 (95: 05) and a minimum in T7 (50: 50) with 07.25%. The decreased trend in acidity level resulted from the hydrolysis of polysaccharides and non-reducing sugars. In contrast, acid is employed to convert them to hexose sugars or reducing sugars. The same was observed in the case of Guava- Papaya blend chutney
(Kumar et al., 2020).
The data clearly illustrates the significant increasing pattern from 9.82-29.52% in the acid: Brix ratio. Throughout the storage period, the maximum percentage of the increase in acid: Brix ratio was found in T2 (95:05) and the minimum increase % was in T7 (50:50). This is due to a chutney’s increasing TSS and decreasing acidity level. The strawberry processed products also observed a similar trend
(Khan et al., 2014). At the same time, the Ascorbic acid of blended chutney reduced dramatically from 9.52-3.24%. The decrease was maximum in T1 (100:00) with 9.52% and minimum in T7 (50: 50) with 3.24%. This decreasing trend is due to trapped oxygen accumulated within the glass bottle. When ascorbic acid reacts with oxygen, it produces a volatile and unstable dehydro-ascorbic acid
(Nayak, 2012; Jakhar et al., 2013) and then further broken down into keto-gluconic acid
(Kuchi et al., 2014). The same was observed in Guava-Jamun
(Bhardwaj et al., 2016) and Gongura chutney
(Kowsalya et al., 2018). The percentage of total sugars and reducing sugars were increased over a storage time. Among the treatments, total sugar percentages ranged from 42.40 to 46.36% and reduced sugars from 4.65 to 10.46%. The percent of the increase was maximum in T1 (100:00) and minimum in T7 (50: 50) in the case of both parameters. The conversion of insoluble polysaccharides into simple sugars led to a gradual rise in the sugar content.
(Policarpo et al., 2007; Menezes et al., 2011) The same was observed in Bael-mango chutney
(Sharma et al., 2019).
Sensory evaluation
The sensory parameters showed a considerable drop in chutney, as recorded in Table 2. The varying colour of the prepared papaya-tomato blend chutney was recorded by matching the colour with the Royal Horticultural society’s Colour Chart
(Wilson 1938). the colour varied differently for each storage interval. Comparatively, less colour change was observed in T5 (50:50) and maximum variation occurred in T1 (100:00) from 40 A-40B (vivid reddish-orange). In the case of flavour, texture and consistency, T6 (55: 45) and T7 (50: 50) were most acceptable. At the same time, T1(100:00) and T2 (95:05) were the least acceptable due to more significant changes. The appearance of the chutney ranged from glossiness and opaqueness to dullness. T5 (65: 35), T6 (55: 45) and T7 (50: 50) showed the same appearance of opaqueness, but T1(100:00) and T2 (95:05) showed dullness on the 90th day of the storage period.
The overall acceptability rating was considered based on all the parameters. The pattern of overall acceptability rating declined considerably from 8.93 to 5.89 as the storage time progressed but varied with different treatments. The changes like appearance, flavour texture and consistency are due to chemical changes or enzymatic and non-enzymatic variations in its composition. For example, a low temperature slows reactions such as oxidation, caramelization and enzymatic activity, leading to a loss of colour, look, texture and taste. A similar result was also seen in Guava- Papaya blend chutney
(Kumar et al., 2020) and wild pomegranate chutney
(Thakur et al., 2018).
Regarding biochemical parameters, the maximum variation was noticeable in T1 (100:00) and the minimum variation was noticeable in T7 (50: 50). These biochemical variations ultimately affected the sensory changes in the chutney. Hence due to lesser changes acceptance rate was higher in T7 (50: 50).