Storage stability of soy protein isolate films incorporated with mango kernel extract at different temperature

This research investigated the storage stability of antioxidant films made from waste and by-products which are soy protein isolate (SPI) and mango kernel extract (MKE) stored at room temperature (25 °C), refrigeration temperature (4 °C) and frozen temperature (−18 °C) for 90 days. The thickness of the films was maintained from 0.050 to 0.058 mm until the 90th day. The colour properties of SPI films incorporated with MKE (SPI + MKE) were generally not significantly affected by time and temperature except for the b value. All the films turned darker over the storage time. There was no dominant factor between temperature and time for the mechanical properties; all the films showed an increase in tensile strength and Young's modulus, and a decrease in elongation. The antioxidant activity of the films was determined by the total phenolic content and radical scavenging activity of DPPH and ABTS. SPI + MKE film at 25 °C showed the highest antioxidant activity as compared to films stored at 4 °C and −18 °C in all the analyses, with the result being significant in DPPH and ABTS analyses. The film stored at 25 °C showed 26 to 50% higher (p > 0.05) TPC than films stored at 4 °C and −18 °C, respectively and had the highest antioxidant activity (54%) in ABTS analysis (p < 0.05). SPI + MKE film stored at 25 °C also showed only 1% depreciation of radical scavenging activity (RSA) throughout the storage time. The highest decrease (4%) in antioxidant activity was recorded for SPI + MKE film stored at −18 °C, although it was considered very low. This shows that the antioxidant activity of the films is stable for 90 days of storage

Functional and antioxidant properties of protein-based films incorporated with mango kernel extract for active packaging

This research is focused on developing active packaging by using food industries’ by-products. Soy protein isolate (SPI) and fish gelatin (FG) were used as the sources of biopolymers and different concentrations of mango kernel extracts (MKE) from 1 to 5% were added as natural antioxidants. Thicker and more translucent films (p < 0.05) were produced when a greater concentration of MKE was incorporated in both films. The mechanical test revealed that the addition of MKE increased the tensile strength of both films (p < 0.05), with higher tensile strength recorded in FG films than in SPI films. The incorporation of MKE significantly (p < 0.05) decreased the water solubility up to 22 and 33%, in FG and SPI films, respectively. The water vapor permeability (WVP) of SPI with the incorporation of MKE improved up to 10%. In contrast, FG films incorporated with MKE showed higher WVP in comparison with the control. The antioxidant activity increased with a greater concentration of MKE incorporated in both antioxidant films (p < 0.05) with more impact in SPI films compared to FG film in DPPH, FRAP and ABTS analysis. DPPH analysis on SPI films revealed the highest antioxidant activity (89%) with the inclusion of 5% MKE extract. Though both films were found to have the potential to be developed as antioxidant films, yet the overall observations revealed that SPI outperformed FG as active packaging films

Development of biodegradable protein-based films incorporated with mango kernal extract for active packaging of mayonnaise

Active packaging is a novel idea in which active substance such as antioxidant is incorporated into the packaging to prolong the shelf-life and maintain the quality of food product. This research was focused on developing active packaging by using food industries’ by-products. In the first objective, soy protein isolate (SPI) and fish gelatin (FG) were used as the source of biopolymers and different concentration (1, 3 and 5%) of mango kernel extracts (MKE) were added as natural antioxidants. The addition of MKE produced thicker and more opaque films (p < 0.05), increased the tensile strength (p < 0.05) and antioxidant activity (p < 0.05) but decreased the water solubility (p < 0.05). The overall observations revealed that SPI outperformed FG as active packaging films. In the second objective, the storage stability of antioxidant films was studied at 25°C, 4°C and -18°C for 90 days. The temperature and time did not have significant effect (p > 0.05) on thickness and colour. All the films showed an increase in tensile strength, decrease in elongation and increase in Young’s modulus (p < 0.05). The highest decrease in antioxidant activity was only 4% throughout the storage time. This shows that the antioxidant activity of the films is stable for the 90 days of storage. In the third objective, the mayonnaise packaged in control and SPI+MKE films turn significantly (p < 0.05) darker and the pH values significantly (p < 0.05) increased after 6 weeks of storage. The SPI+MKE films were able to slow down the lipid oxidation by 30% in peroxide value analysis, 44% in TBARS analysis, 38% in anisidine value analysis and 65% in total oxidation analysis. Therefore, the usage of the SPI+MKE films could maintain the quality of mayonnaise for a longer time

Development of fish gelatin coatings incorporated with lemon peel extracts as antimicrobial packaging to extend the shelf life of Flammulina velutipes

Antimicrobial coatings based on fish gelatin with lemon peel extract (LPE) were developed to extend the shelf life of mushroom (Flammulina velutipes). Fish gelatin coatings incorporated with LPE successfully reduced up to 20% microbial growth on the mushroom on the 12th day of storage as compared with control. Lower temperature (4ºC) maintained the quality of mushrooms better than the higher temperature (25ºC) for all analyses. The sensory evaluation revealed that browning became prominent only on 8th day onwards at both temperatures. The overall acceptability showed that the coated mushroom sample is still acceptable even after the 8th day