Development of an Indicator Film Based on Cassava Starch-Chitosan Incorporated with Red Dragon Fruit Peel Anthocyanin Extract

Effect of using biodegradable film constituting red grape anthocyanins as a novel packaging on the qualitative attributes of emergency food bars during storage

This study presents a novel packaging film based on whey protein isolate/κ-carrageenan (WC) with red grape pomace anthocyanins (RGA) to investigate its impact on some qualitative attributes of emergency food bars (EFBs) for 6 months at 38°C. Increasing the RGA dose in WC films from 5% (WCA5) to 10% (WCA10) reduced hydrogen bonding between polymers and polymer homogeneity in the matrix according to FTIR and SEM. Tensile strength slightly declined in WCA5 from 7.47 ± 0.26 to 6.97 ± 0.12, while elongation increased from 27.74 ± 1.36 to 32.36 ± 1.25% compared to WC film. The maximum weight loss temperature (TM) increased by incorporating 5 wt% RGA from 182.95°C to 244.36°C, whereas TM declined to 187.19°C in WCA10 film. WVP and OTR slightly changed in WCA5 (from 7.83 ± 0.07 and 2.57 ± 0.18 to 8.41 ± 0.03 g H2O.m/m2.Pa.s × 10-9 and 1.79 ± 0.32 cm3 O2/m2.d.bar, respectively), but significantly impaired in WCA10 compared to WC film. WCA5 and WCA10 films had high AA%, 68.77%, and 79.21%, respectively. WCA10 film presented great antimetrical properties against Staphylococcus aureus with an inhibition zone of 6.00 mm. The light transmission of RGA-contained films in the UV spectrum was below 10%. The WCA5 film effectively restrained moisture loss and hardness increment until the end of the storage period, which were 14.33% and 28.76%, respectively, compared to day 0. Antioxidant films provided acceptable resistance against oxidation to EBF treatment. Sensory panels scored WCA5 and WCA10 higher in overall acceptance with 5.64 and 5.40 values, respectively, while complaining about the hardness of OPP treatment. The results of this investigation demonstrated that incorporating RGA, preferably 5 wt%, into WC-based film effectively improved the qualitative properties of EFB during the 6-month shelf life. This film might be a promising alternative for packaging light and oxygen-sensitive food products.

Fabrication of freshness indicators based on methylcellulose-containing color indicator solutions for monitoring the quality of coconut water

This is the first study to apply intelligent packaging to coconut water. The purpose of this study was to determine the best color indicator solution for making freshness indicator labels based on methylcellulose along with the color change profile of coconut water during storage at room temperature. Three color indicator solutions were used, namely phenol red, bromothymol blue, and methyl red, which were then continued with the fabrication of freshness indicator labels based on methylcellulose from each of these color indicator solutions and applied to coconut water at 25 °C room temperature storage for 24 h with observations every 4 h in the form of pH, total dissolved solids, total acid, turbidity, total microbes, CO2 gas, O2 gas, and freshness indicator label color changes. The values of pH, total soluble solids, and O2 gas decreased with storage time, whereas the values of total acid, turbidity, total microbes, and CO2 gas continued to increase. The methylcellulose-based phenol red freshness indicator label provides the best color change profile that matches the freshness condition of coconut water, namely purplish red (fresh), orange (immediately consumed), and yellow (damaged) so that it can be used as intelligent packaging to monitor the quality of coconut water.

Development of alginate-based film incorporated with anthocyanins of red cabbage and zinc oxide nanoparticles as freshness indicator for prawns

The objective of this study was to develop pH-sensitive film indicators for intelligent food packaging by incorporating red cabbage anthocyanins (RCA) and zinc oxide nanoparticles (ZnO NPs) into an alginate (Alg) film, aiming to mitigate the risk of foodborne illnesses. The films were fabricated using a solvent-casting method and crosslinked with a calcium chloride (CaCl2) solution. Thorough evaluations of the films' physical, mechanical, and structural properties demonstrated significant improvements in elastic modulus and UV/vis light barrier characteristics, reduced water vapor permeability (WVP), and moisture content attributed to integrating RCA and ZnO NPs. The resulting film displayed discernible color changes when exposed to various pH buffer solutions and ammonia vapor, indicating heightened sensitivity to pH fluctuations due to the presence of ZnO NPs. Visual assessment using prawns as test specimens revealed a color shift from violet (indicating satisfactory condition) to blue-greenish (indicating spoilage), corroborated by colorimetric analysis. Moreover, the Alg/ZnO/RCA film exhibited antioxidant and antibacterial properties, demonstrated biodegradation activity, and showed no toxic effects on RSC96 cells, further underscoring its potential as an effective freshness indicator for food products.

Development of Indicator Film Based on Cassava Starch-Chitosan Incorporated with Red Dragon Fruit Peel Anthocyanins-Gambier Catechins to Detect Banana Ripeness

Banana ripeness is generally determined based on physical attributes, such as skin color; however, it is considered subjective because it depends on individual factors and lighting conditions. In addition, improper handling can cause mechanical damage to the fruit. Intelligent packaging in the form of indicator film incorporated with anthocyanins from red dragon fruit peel has been applied for shrimp freshness detection; however, this film has low color stability during storage, necessitating the addition of gambier catechins as a co-pigment to increase anthocyanin stability. Nevertheless, the characteristics of films that contain gambier catechins and their applications to bananas have not been studied yet; therefore, this study aims to develop and characterize indicator films that were incorporated with red dragon fruit peel anthocyanins and gambier catechins to detect banana ripeness. In this study, the indicator films were made via solvent casting. The films were characterized for their structural, mechanical, and physicochemical properties, and then applied to banana packaging. The results show that the film incorporated with anthocyanins and catechins in a ratio of 1:40 (w/w) resulted in better color stability, mechanical properties, light and water vapor barrier ability, and antioxidant activity. The application of the indicator films to banana packaging resulted in a change in color on the third day of storage. It can be concluded that these films could potentially be used as an indicator to monitor banana ripeness.

Characterization and qualitative evaluation of cassava starch-chitosan edible food wrap enriched with culinary leaf powders for eco-friendly food packaging applications

Cassava starch-based edible food wraps were prepared by incorporating leaf powder from Indian curry leaf and Malabar bay leaf, reinforced with different (0.2, 0.4, 0.6, 0.8) wt.% of chitosan. Eleven combinations of films were prepared and their sensory acceptability, physical properties, Fourier-transform infrared spectroscopic (FTIR) spectrum, and scanning electron microscopy (SEM) image, were evaluated. The thickness of the films ranged from 0.198  ±  0.12 to 0.372  ±  0.27 mm. Tensile strength was reported to be the highest (40.71  ±  1.21 MPa) in the curry leaf powder incorporated sample. Maximum elongation at break was reported by bay leaf powder incorporated (5.8  ±  1.59%) sample. The Young's modulus values were observed to be increasing along with the concentration of chitosan. Maximum seal strength values were reported by curry leaf powder incorporated film with 0.8% chitosan (2.93  ±  0.22 N/mm). The leaf powder incorporated samples reported a higher flavonoid content compared to the control. The color analysis (L*, a*, b*) of the films was identical to the natural leaf color. The SEM images indicated a rough texture for the leaf powder incorporated films. The FTIR evaluation confirmed the presence of the respective functional groups. The statistical evaluation done by statistical package for social sciences software showed that all the data were significantly different (P ≤ 0.05.). The study demonstrated the potential of incorporation of leaf powder and chitosan to enhance the properties of starch-based edible packaging.

Dragon Fruit Peel Extract Enriched-Biocomposite Wrapping Film: Characterization and Application on Coconut Milk Candy

Bio-based film is an eco-friendly alternative to petroleum-based packaging film. The effects of biocomposite wrapping film enhanced with dragon fruit peel extract (0, 2% w/v, respectively) and currently used commercial packaging film (polypropylene; PP) on coconut milk caramels during storage (30 °C, 75% RH, nine days) were studied. Both 0% and 2% DPE-enriched biocomposite films were thicker and had higher water vapor permeability and solubility than the PP film but poorer mechanical characteristics. In addition, the 2% film possessed antioxidants and antioxidant ability. A FESEM micrograph revealed the rough surface and porous path of the biocomposite films. Over the storage time, the moisture content, water activity, and springiness of the coconut milk caramel candy wrapped in the PP and all DPE-enriched biocomposite films were not significantly altered. However, the lipid oxidation as the thiobarbituric acid reactive substance (TBARS) and hardness of all coconut caramels were significantly (p < 0.05) increased during storage. Furthermore, the hardness of coconut candy covered in the control (0% DPE) biocomposite film was more pronounced on day nine of storage. However, the changes in quality characteristics of the coconut candy wrapped in each film type need to be better established. The investigating factors influencing the quality deterioration of coconut milk candy should be further identified to mitigate their effects and extend the shelf-life of the coconut candy.