Colocasia leaves are high in nutrients and other phytochemicals but their utilization remains limited due to a lack of awareness. Higher content of anti-nutritional factors like oxalic and tannic acid in Colocasia leaves limit nutrient availability. In the present study, the effect of four household procedures viz. soaking (8–12 h), microwave heating (2–6 min), cooking (30–60 min), and blanching (1–3 min), followed by sun drying, was studied on the nutritional, antinutritional and functional properties of Colocasia leaves. A significant increase in crude fibre (25.7%–29.65%), and protein (4.33–15.6%) content was found in all the treatments except for the microwave treatment. A significant decrease in fat (5.7–31.4%), ash (20.34–28.22%), oxalic acid (27.07–35.32%), and tannic acid (up to 96%) was also found in various treatments. Among the minerals, a significant increase was reported for calcium (up to 16.38%), and iron (up to 5.9%). The highest mineral retention was found in soaked samples. The soaked and cooked samples also had a higher Ca: Mg ratio. A significant change in functional properties was also found. FTIR peaks suggested no significant qualitative effect occurred on phytochemical or physicochemical characteristics. Cluster analysis showed that cooking was second to soaking in terms of overall quality which were most comparable to the control. Cooking efficiently reduced the antinutritional factors, however, a significant loss of nutrients and functional properties was also observed. Therefore, the soaking of Colocasia leaves for 8–10 h is recommended as the best practice before their food applications.

Bottle gourd pomace, a waste from vegetable processing industry was used to prepare instant kheer (dessert) mix. In this study, the bottle gourd was procured from the farm, washed, grated, steam blanched and the grits were further divided into two parts. One part of grits was dried without juice extraction (BGFD- Bottle gourd fresh dried), while, the other half (BGPD- Bottle gourd pomace dried) was dehydrated after extraction of juice. The dehydrated grits were used for the preparation of kheer mix and the recipe was optimized using RSM Central Composite Design (CCD). The variables were BGFD and BGPD ranged 3–7 g. The other ingredients with the fixed quantities were milk powder (50 g), sugar (15 g), and small cardamom (1 g). The product was selected based on sensory responses like taste, colour, flavour, texture, and overall acceptability (OAA). The software suggested a kheer mix prepared using 7 g BGFD and 3 g BGPD will produce the best sensory scores. The prepared kheer mix had a moisture, TSS, carbohydrates, reducing sugars, total sugars, titratable acidity, crude protein, and crude fat content of 7.9%, 27 °B, 72.21%, 10.79%, 16.75%, 0.896% CA, 10.76%, and 7.63%, respectively. The product was rich in energy (400.55 kcal/100 g), total phenols (4.99 mg/100 g), and exhibited strong antioxidant activity (46%). The total plate count on the product on nutrient agar medium was 4.3 × 10⁶ CFU/g. The kheer could be prepared by adding 140 mL of water to 70 g of water to kheer mix and cooking it for 10 min. Further, to see the credibility and obtain more clearer patterns, the Canonical Correlation Analysis (CCA) and Principal Component Analysis (PCA) were applied. The overall variation of the BGFD and BGPD on the sensory parameters based on canonical correlation analysis was 92.5%. The sum of Principal Components PC1 and PC2 explained a very high variability (98.2%) among the studied treatments.