No abstract

Copper nanocomposite containing edible bilayer pouch was fabricated from a heat sealable casein protein layer laminated with sodium alginate–pectin, and the developed pouch was used to package the coconut edible oil. The copper nanocomposite was synthesized by using heat treated and NaBH4 treated methods. The synthesized nanocomposites were incorporated in the bilayer film. Effect of incorporation of copper nanocomposite on mechanical, barrier, and antimicrobial properties of the film was then investigated. Addition of nanocomposite improved the tensile strength (TS), light barrier properties but reduced the % elongation at break. Thermal stability of the bilayer was improved after the addition of nanocomposite. Antimicrobial property of heat treated nanocomposite containing film (zone of inhibition 11 mm) was higher than to the film containing NaBH4‐treated nanoparticles (inhibition zone 4 mm) against the growth of Escherichia coli. Lower WVTR and less transparency of the film made it suitable to reduce the rate of oxidation of coconut oil during storage. Rate of increase in oxidation of coconut oil was significantly less (i.e., 14 meqiv. kg−1 after 90 days of storage) when stored in nanocomposite containing edible pouches. Practical applications Usages of plastic packaging material have a number of drawbacks like generation of waste associated with the materials used to package foods; tearing of the package for the use of the oil is little bit difficult for the consumer and left over after use may get waste. Edible packaging prepared from natural sources may be an effective alternative to avoid the problem of disposing of packaging material. Single‐layer edible packaging is not so acceptable for commercial packaging due to poor barrier properties, and therefore, in the present investigation, lamination of pectin–sodium alginate and casein was used for the fabrication of bilayer edible pouches. Synthesized copper nanocomposite was incorporated in pectin layer to improve the antimicrobial properties of the film. In present investigation, the developed pouch was used to package the edible coconut oil and the oxidative stability of oil during storage was also studied.

Quality of bamboo shoots gets deteriorate rapidly during storage and transportation due to enzymatic browning and microbial attack. Therefore, effect of blanching temperature (75, 85 and 95°C) and time (5, 10, 15, 20, 25 and 30 min) on different physic-chemical properties of bamboo shoot cubes were assessed. Blanching time and temperature have significantly influenced the nutrients like protein, carbohydrate and reducing sugar contents. The highest changed in values of protein, carbohydrate and reducing sugar were reported from 3.42 to 2.24, 4.08 to 2.25, 1.33 to 0.87 g/ 100 g, respectively. The influence was less on ash and crude fiber. Retention of ascorbic acid, total phenolics and antioxidants were higher in 75°C and/or short time blanching (5-10 min) which were gradually reduced at 85 and 95°C and/or long time blanching (20-30 min). The higher blanching temperature decreases in lightness value and long time blanching deteriorate the texture of bamboo shoot. Low temperature short time blanching was shown to result in better product quality with respect to physical properties besides nutrient retention.

The impact of heat-moisture treatment (HMT) and annealing (ANN) on morphology, crystallinity, pasting, and thermal properties of sohphlang starch are determined. Heating of starch with 20%, 25%, and 30% moisture at 100 °C for 16 h is done for HMT while ANN is done for 24 h using 70%, 75%, and 80% moisture levels at 50 °C. Both HMT and ANN result in a rough surface structure and decreased birefringence at the center. The 1047/1022 ratio and crystallinity increase on modification but the A-type polymorph remains unchanged. Hydrothermal treated starches have significantly increased pasting temperatures and reduced pasting viscosity; HMT starches no longer possess pasting profiles because of lack of trough viscosity; hence no breakdown and setback. Annealed starches show higher final viscosity than native starch (NS) and HMT starches. Both HMT and ANN improve the thermal properties by elevating gelatinization temperatures and gelatinization enthalpy. Moisture levels have a significant impact on the properties of NS, HMT, and ANN starches. Though annealing with 80% moisture alters the sohphlang starch properties, the effect is found to be lesser when compared to heat moisture treatment with 30% moisture. Thus, overall results convey that HMT and ANN can be used as modification techniques of sohphlang starch to modify the properties that can be useful in food applications.

No abstract