Iranian Food Science and Technology Research Journal

Abstract The aim of this study was to develop and characterize carboxymethylated agar (CMA) based films crosslinked with citric acid, polyethylene glycol (PEG), and β-cyclodextrin for sustainable food packaging applications. The inherent brittleness, high hydrophilicity, and limited thermal stability of native agar films, which restrict their practical use in food packaging systems were considered as the aim of performing this study. Five distinct film formulations were prepared using different combinations of crosslinking agents, and their physicochemical, morphological, and thermal properties were systematically evaluated. The degree of substitution (DS) of carboxymethyl agar was determined to be 0.69, indicating successful chemical modification. Water contact angle analysis revealed that the CMA-P-β-A film exhibited the highest hydrophobicity, with a contact angle in the range of 80–89°, compared to approximately 67° for the control CMA film, demonstrating enhanced moisture resistance. Differential scanning calorimetry showed a significant increase in glass transition temperature (Tg), reaching 82.08 °C for the CMA-P-β-A formulation, compared to 52.54 °C for CMA, confirming the formation of a highly crosslinked polymer network. FTIR and XRD analyses confirmed successful carboxymethylation and crosslinking, accompanied by reduced crystallinity and improved structural flexibility. SEM micrographs revealed smooth and homogeneous surfaces with interconnected polymer networks. Overall, the integrative carboxymethylation crosslinking strategy effectively enhanced the hydrophobicity, thermal stability, and structural integrity of agar-based films, highlighting the CMA-P-β-A formulation as the most promising candidate for environmentally friendly food packaging applications. These findings provide valuable insights into the design of advanced biopolymer-based packaging materials.

Abstract Increasing concerns about human health have increased demand for functional bioactive compounds, such as vitamins E and C. However, their inherent instability and susceptibility to environmental conditions have restricted their direct application in food systems. Encapsulation strategies offer an effective approach to protect these vitamins from degradation and enable controlled release. This study aimed to develop a stable encapsulation system for vitamins E and C using a whey protein concentrate–chitosan (WPC–CS) complex through spray drying, enabling simultaneous delivery of hydrophilic and lipophilic vitamins. Response surface methodology (RSM) was applied to optimize the formulation with the objective of maximizing encapsulation efficiency while minimizing moisture content and hygroscopicity. The optimal microcapsule exhibited encapsulation efficiencies of 93.83% and 93.6% for vitamins E and C, respectively, with a low moisture content (3.17%) and controlled hygroscopicity (13.18%). Release studies demonstrated a phase-dependent behavior: vitamin C showed negligible release in simulated mouth fluid (0.07% after 10 min) but a substantial cumulative release in simulated gastric fluid (85.74% after 120 min). In contrast, vitamin E exhibited a slower and sustained release profile, with 31.45% released after 120 min in simulated gastric fluid and no detectable release under mouth conditions. Scanning electron microscopy (SEM) analysis revealed that the microcapsules had a predominantly spherical morphology with a wrinkled surface, characteristic of protein–polysaccharide matrices formed during rapid drying. Fourier transform infrared spectroscopy (FTIR) confirmed successful encapsulation of both vitamins through interactions between WPC and CS. These findings indicate that WPC–CS complexes produced via spray drying provide an effective co-encapsulation and controlled-release system, enhancing vitamin stability and offering promising applications in functional foods and pharmaceutical formulations.

Abstract The consumer trend toward safe and healthy food has spurred research and application of natural colors in traditional biscuit products to improve quality and sensory value. Perilla frutescens (L.) Britton is a member of the Lamiaceae family and is widely found in East Asian regions, where it is used as both a spice in cooking and in traditional medicine. It is rich in anthocyanins, a class of polyphenolic compounds that act as natural colorants and possess strong antioxidant properties. This study aimed to evaluate the extraction process of perilla leaf for enriching the total anthocyanin content, which is applied in coloring butter biscuits. The investigated factors included the sample-to-water ratio for extraction (1:10, 1:15, 1:20, and 1:25 g:mL), extraction temperatures (60°C, 70°C, 80°C, and 90°C), and extraction times (20, 25, 30, and 35 minutes). The obtained extract was analyzed for anthocyanin content using the pH differential method. The findings suggested that a sample-to-water ratio of 1:20 g:mL, an extraction temperature of 90°C, and an extraction duration of 30 minutes were the most suitable extraction conditions to achieve a high total anthocyanin content (1.70 mg.g^-1 DW). The addition of perilla leaf extract (PLE) significantly affected the physical properties of the biscuits (diameter, yield, brightness, and hardness of the biscuits); the higher the amount of PLE added, the darker and crispier the biscuits became. Sensory analysis showed that biscuits supplemented with PLE were rated higher than the control in terms of texture, color, and flavor. The results showed that the biscuits that received the highest scores across all parameters were supplemented with PLE at a rate of 7.5%. Overall, the analysis suggests that it is possible to produce butter biscuits with a characteristic color and improved nutritional profile by adding PLE.

Abstract Growing concerns about conventional plastic packaging due to its non-degradability, risk of transferring toxic compounds to food, and environmental pollution have necessitated the development of environmentally friendly alternatives such as edible and biodegradable films. This study aimed to develop an active packaging system based on a polycaprolactone/beta-glucan (PCL-BG) nanocomposite film modified with oak fruit pair extract (OFPE), apricot kernel extract (AKE), and gold nanoparticles (AuNPs) and study its suitability for packaging fish paste treated with cold plasma. The evaluation of the film's antibacterial properties showed that the active compounds had a strong inhibitory effect, with the largest inhibition zones of 27.78 mm against Bacillus cereus and 21.38 mm against Escherichia coli observed in the film prepared with the highest extract concentration. Thermal analysis (DSC) showed a significant improvement in thermal stability, with the melting temperature of the final composite film increasing to 81.6 °C. Microbiological and chemical evaluations over 30 days of storage showed that the combined treatment significantly (p < 0.05) reduced microbial growth (Total Viable Count), reduced the production of volatile nitrogen compounds (TVB-N), controlled lipid oxidation (TBA), and maintained pH stability and sensory acceptance. Regression models for all quality parameters showed high accuracy and predictive power (R² > 99.27%). This study clearly demonstrates the effectiveness of the combined strategy of cold plasma and active packaging in maintaining the quality and increasing the shelf life of fish paste.

Abstract In this research, gelatin was extracted from various by-products of silver carp (Hypophthalmichthys molitrix) (SC) and rainbow trout (Oncorhynchus mykiss) (RT), including skin, soft tissue, head, and vertebrae. The extracted gelatins were evaluated for proximate composition, molecular weight, functional properties, and structural characteristics. The findings revealed that the protein content of the gelatin samples ranged from 69.25% to 85.75%, with fat levels below 1.5%. The highest moisture content was observed in RT-skin gelatin (16.8%), while the lowest was found in RT-vertebral bone gelatin (2.97%). SDS-PAGE analysis showed clear 1α (~114–121 kDa) and 2α (~100–112 kDa) chains in skin and cranial soft tissue gelatins, whereas bone-derived samples lacked distinct bands, indicating extensive collagen degradation due to harsh acid treatment. In terms of viscosity, the highest value (11 cP) was recorded for SC-cranial soft tissue gelatin, and the lowest (2.6 cP) for RT-head gelatin. Gel strength ranged from 573.5 g (SC-skin) to 19.6 g (RT-head). The melting point of SC-gelatins was significantly higher than that of RT, with some samples approaching values similar to bovine skin gelatin. SC-vertebral bone gelatin exhibited the greatest foaming capacity (120 ± 2%), while SC-head gelatin demonstrated the highest foam stability (48.03 ± 2.12%). These results suggest that non-commercial by-products from these two fish species, especially SC-skin and cranial soft tissue, represent valuable potential sources for producing high-quality gelatin for food applications.

Abstract The growing demand for convenient, nutritionally balanced snack products has created opportunities for utilizing underutilized local ingredients in food product development. This study aimed to develop snack bar using Tahitian chestnut (Inocarpus fagifer) and cowpea (Vigna unguiculata) flours as locally available raw materials and to evaluate their physicochemical, sensory, antioxidant, and microbiological characteristics. Five formulations with varying Tahitian chestnut to cowpea flour ratio [A = 1:1; B = 1:5; C = 2:1; D = 1:2; E = 5:1] were prepared using a completely randomized design. The results showed that the incorporation of Tahitian chestnut and cowpea significantly affected (p < 0.05) several physicochemical parameters, including color, texture, moisture, dietary fiber, macronutrient composition, and antioxidant properties, while ash content was not significantly influenced. Sensory attributes and microbiological quality were not significantly affected, with all formulations meeting acceptable hedonic and safety criteria. Based on the Zeleny multi-criteria decision method, formulation E (Tahitian chestnut:cowpea ratio of 5:1) was identified as the most balanced formulation among those evaluated. These findings demonstrate the potential of Tahitian chestnut and cowpea flours for snack bar development and provide baseline information for further utilization of local ingredients in value-added food products.