Volume 16, Issue 91 (September 2019)
Abstract
The purpose of this study was to investigate the possibility of producing a biodegradable film from a new source known as opopanax gum and investigating its physical and mechanical properties. Opopanax gum was purified after two extraction steps and the film was prepared with 4% gum solution and 2.5% glycerol in deionized water. The apparent viscosity of the film solution showed the non-Newtonian shear thickening behavior of the solution. The contraction ratio obtained from opopanax gum film was -0.267 ± 0.095. Water vapor permeability (WVP) of opopanax film was 25.059 ± 0.623. The tensile strength and the elongation percentage at break point obtained for opopanax gum film were 0.376 ± 0.124 MPa and 350.625±108.599, respectively. The opacity percentage of the film was 15.633 ± 0.404, which indicates the desirable clarity of the film. The average contact angle for the film was 34.618 ± 1.992, which can be said that the film is relatively sensitive to humidity. The X-ray diffraction spectrometer pattern showed the semi-crystalline structure of the film. Two endothermic peaks and two exothermic peaks were observed in the DSC thermograms. The thermal analysis of the film also showed 4 mass losses. The structure of the film was investigated using Atomic Force Microscopy. The FTIR test showed that the main part of the film is polysaccharide. The total results from different experiments showed that opopanax gum has the ability to form film. However, opopanax gum is not alone desirable to produce edible film due to its high thickness, high solubility in water, high permeability to water vapor and poor mechanical properties. Therefore, it could be an appropriate option for combining with other films to enhance biodegradability of the films.
Volume 19, Issue 122 (April 2022)
Abstract
In this study, natural dye curcumin wasused to monitor the quality of packaged fish meat through color changing indicators and the color changes of the indicators were evaluated visually and with colorimeter during storage of fish samples at room temperature (for 60 hours) and in the refrigerator (for 12 days). In order to evaluate performance of paper indicators for monitoring the quality of fish, the quality characteristics of fish such as total viable count, pH, and TVB-N were evaluated. This indicator had very good characteristics such as less moisture absorption than the control, excellent stability during storage for 30 days, and high selectivity to pH changes. The FTIR results showed that the curcumin was well stabilized on cellulose filter paper. The results of color changes of the indicator during fish storage indicated that with increasing the storage time, the brightness (L *) of the indicator based on curcumin significantly decreased and red-green (a *) and yellow - Blue (b *) parameters increased. Colorimetric indicator based on curcumin indicated significant color changes from yellow to orange due to sensitivity to pH and detection of TVB-N and hydrogen sulfide compounds. According to the results obtained from the qualitative characteristics of fish in relation to performance and function of colorimetric indicator during fish spoilage, it can be concluded that curcumin provides a promising approach in intelligent packaging systems for meat products to monitor fish meat freshness.
Volume 19, Issue 127 (September 2022)
Abstract
Carbon quantum dots are a new generation of carbon nanoparticles that have good potential for food analysis and packaging due to their unique properties such as excellent fluorescence properties, easy synthesis, good biocompatibility, large functional groups, and low toxicity. Today, carbon quantum dots have replaced semiconductor quantum dots due to their non-toxicity. The use of carbon dots in packaging materials due to their antioxidant, antimicrobial and barrier properties increases product shelf life, reduces the growth of microorganisms, improves mechanical properties, the barrier against gases, UV light blocker, and reduces food waste. This paper aims to get acquainted with carbon quantum dots and synthesis methods and study their optical properties. Then, the principles of fluorescence sensor design, including the mechanism of fluorescence quenching and recovery and their application in food samples to detect food additives, pathogens, antibiotic residues, insecticides, heavy metals, and nutrients will be examined. Finally, the use of carbon dots in improved, active, intelligent and bio-packaging will then be discussed.
Volume 27, Issue 2 (2-2025)
Abstract
There is a growing trend towards healthy meat products containing lower fat content. The use of fat replacers can solve the quality problems of low-fat products. This study aimed to produce low-fat frankfurter sausage using a new fat replacer. Thus, in the first stage, Reconstituted Agar Hydrogel (RAH) was produced by adding water to agar cryogel after homogenization. In the second stage, RAH was used as a fat substitute in frankfurter sausage at 0, 25, 50, 75, and 100%. Then, the characteristics of the resulting low-fat sausage, including chemical composition, water holding capacity, cooking loss, texture characteristics, porosity, color, percentage of fat after frying, oil absorption, pH over time, and sensory evaluation were examined. Results showed that RAH could form two kinds of gel by temperature changes: a low-set gel at 55˚C and a high-set gel at 90˚C. Substitution of oil in the sausages caused an increase in moisture content, porosity, oil absorption, and cooking loss. On the other hand, this replacement reduced fat content, cutting force, water-holding capacity, fat percentage after frying, and texture properties such as hardness, cohesiveness, springiness, gumminess, and chewiness. The results of pH measurements over time showed that sulfated antimicrobial groups in the agar structure delayed the spoilage of sausages containing RAH compared to the control sample. Sensory evaluation showed that RAH-containing sausages were not significantly different from the control sample in terms of color, juiciness, and texture. However, flavor and overall acceptance increased significantly under the influence of this substitution (P< 0.05). Therefore, the consumers selected a sample with 25% replacement as the optimal sample. As a result, RAH can be successfully used as a fat replacer in low-fat products with desirable quality characteristics.
