ABSTRACT
The study reveals effect of pre-treatments, i.e., partial drying (PD), partial drying + freezing (PDF) and freezing (F) on physico-chemical, structural and sensory quality of vacuum fried papaya chips (100 °C for 28 min at 13.33 kPa). Pre-treatments significantly (p < 0.05) influenced the quality parameters of vacuum fried papaya chips. Partial drying pre-treated sample showed significantly (p < 0.05) higher reduction in oil uptake, i.e., 19.61% (d.b.) besides retaining significantly (p < 0.05) higher total phenolics content (394.07 mg/100 g gallic acid equivalent) as compared to other samples. Ascorbic acid content was retained significantly (p < 0.05) high in untreated control samples (209.81 mg/100 g). Freezing pre-treatment was found better in retaining total flavonoids, total carotenoids and antioxidant activity. The SEM micrographs of papaya chips showed dense and shriveled structure due to partial drying pre-treatment, however, more porous structure was observed in freezing pre-treated sample as compared to control. Freezing pre-treated samples were also rated high on hedonic scale for their sensory parameters, i.e., colour, crispness, taste, mouth feel, appearance and overall acceptability, which were in agreement with instrumental CIE colour values, firmness and microstructural characteristics of samples. The percent moisture, fat, protein, total carbohydrate, and ash content of freezing pre-treated vacuum fried papaya chips was found to be 1.51 ± 0.13%, 23.68 ± 0.12%, 3.42 ± 0.14%, 67.64 ± 1.78% and 3.75 ± 0.08%, respectively.
ABSTRACT
Rice bean (Vigna umbellata) is grown in South and Southeast Asia, and the bean has gained importance due to its nutritional strength in terms of dietary fiber, quality protein and minerals. In current study, the nutritional and functional components, cooking and thermo-gravimetric properties of eleven rice bean varieties from NE India were investigated. Results revealed that the major nutrients among the varieties ranged as follows: 54.21-60.49% carbohydrates, 15.64-21.60% protein, 1.22-2.3% fat, 5.53-6.56% crude fibre, 3.34-3.8% ash; while the functional, anti-nutritional factors and mineral were present as 1189.32-1645.8 mg gallic acid equivalent (GAE)/100 g polyphenols, 205.38-432.14 mg/100 g phytic acid, 23.14-34.12 mg/100 g oxalate, 690.7-1589.5 mg/100 g saponins, 49.90-158.17 µg/100 g hydrocyanide, 111.51-168 calcium, 5.50-10.44 zinc, 3.72-8.37 iron. Principal component analysis revealed that varieties with higher calcium, iron and ash content had lower cooking time, swelling ratio, and cooked grain hardness. It is also revealed that varieties with higher weight loss at sixth stage in thermogravimetric graph had lower carbohydrate and higher protein content. Nagadal variety had higher fat, potassium, magnesium, calcium, sodium, iron, copper and chromium content and better cooking quality as compared to the other varieties. The study revealed that Nagadal variety was superior to other varieties with respect to mineral content, cooking and thermal properties and hence have better potential in the development of value added products.
