Influence of acetylation and chemical interaction on edible film properties and different processing methods for food application.

This study developed sweet potato starch (SPS) based edible films and investigated several methods (acetylation, amidated pectin (AP), and CaCl2 use) to improve the edibility and different processing methods (casting and extruding) to package food possible in commercial use. Starch acetylation was conducted with up to 8 mL of acetic acid (A8) and improved the stretchability and solubility of the film. The AP addition [∼30 wt% (P3)] enhanced the film strength, further increasing solubility. CaCl2 addition [∼150 mg/g of AP (C3)] also positively influenced the film solubility and water barrier properties of the films. The SPS-A8P3C3 film showed 3.41 times higher solubility than the native SPS film. Both casted and extruded SPS-A8P3C3 films drastically dissolved in high-temperature water. When applied to oil packaging, two films could delay the lipid oxidation of the packaged samples. These results demonstrate the usability of edible packaging and extruded film for commercial use.

Novel color stability and colorimetry-enhanced intelligent CO2 indicators by metal complexation of anthocyanins for monitoring chicken freshness.

This study aims to improve the color stability of anthocyanins and develop a CO2-sensitive indicator based on black goji anthocyanin (BGA) extract. Although the BGA extracts showed distinct color changes, such as red-purple-blue, their intrinsic color diminished after 24 h. A metal complexation method was used for the high color stability of BGA. BGA extracts were chelated with various concentrations of Al3+ [0 - 20% (w/w)]. It showed high color stability and strong intensity in a dose-dependent manner. A CO2-sensitive indicator sachet was developed using hydroxypropyl methylcellulose hydrogel, based on 5% (w/w) Al3+-BGA complexes. The indicator was applied to the chicken breast and detected its spoilage after 3 days with its changing color to greyish blue, due to the microbial growth to 7.00 log CFU/g. These results demonstrated the possibility of chelated anthocyanin complexes as indicating dyes and the ability to monitor the food quality changes through noticeable color changes.

Isolation, screening and identification of key components having intense insect repellent activity against Plodia interpunctella from four different medicinal plant materials.

BACKGROUND: Global warming and the indiscriminate use of pesticides have increased the propagation of the stored-product insect pests, leading to enormous losses in the agriculture and food industries. The most used insect repellents are synthetic derivatives; however, these have an adverse effect on human health as well as on the environment. Therefore, we attempted to find materials with insect repellent activity in natural products. The present study aimed to identify the single chemical component with intense insect repellent activity in extracts from four different Oriental medicinal plant materials: (i) Anethum graveolens L. (dill) seeds; (ii) Artemisia capillaris Thunb. (capillary wormwood) leaves; (iii) smoked Prunus mume Siebold & Zucc. (mume) fruits; and (iv) Rhus javanica L. (galls). RESULTS: As a result of the bioassay-guided fractionation of each extract against the Plodia interpunctella, stored-product insect, the n-hexane fraction of dill seeds extract was confirmed as the optimal fraction between all of the fractions. In total, 32 chemical components were identified from the n-hexane fraction of dill seeds by gas chromatography-mass spectrometry analysis, and the two main components were dillapiole (47.51%) and carvone (26.76%). Of the two components, dillapiole was confirmed as the key component playing an essential role in insect repellent activity. CONCLUSION: Our study suggests that dillapiole has the potential to be used as a natural insect repellent for the control of P. interpunctella infestation in agricultural and food products during distribution and storage. © 2021 Society of Chemical Industry.

Effects of mung bean starch/guar gum-based edible emulsion coatings on the staling and safety of rice cakes.

Antimicrobial starch/gum-based edible emulsion coatings were developed to improve the storage stability of rice cakes by retarding starch retrogradation and inhibiting microbial growth. Rice cakes were coated with mung bean starch (MBS) and guar gum (GG) containing various concentrations of sunflower seed oil (SO). Among these, the (2 g MBS +0.75 g GG +1.5 g SO) / 100 g (optimum) decreased the hardness of rice cakes by 29 % and the crystallization rate (k) by 24 % compared with those of uncoated samples. The moisture loss in uncoated samples was markedly higher than that in the optimum blend-coated samples. Crystallinity analysis revealed the retarding effect of the developed coatings in starch retrogradation. Furthermore, adding 0.8 % (w/w) grapefruit seed extract to the optimum blend led to a distinct antimicrobial activity. Therefore, the newly developed edible coating was effective in maintaining the quality and safety of rice cakes.

Development of a biodegradable polycaprolactone film incorporated with an antimicrobial agent via an extrusion process.

In the present study, polycaprolactone (PCL) composite films incorporated with various concentrations of grapefruit seed extract (GSE) as an antimicrobial agent were prepared using a twin-screw extruder. Physical characteristics as well as antimicrobial properties of the PCL/GSE composite films were analyzed. The results showed that the surface color of the films gradually changed with increasing GSE concentration. Fourier transform infrared spectra indicated no significant structural changes such as chemical bond formation between PCL and GSE. Thermal properties were slightly affected due to GSE incorporation. Crystallinity of the composite films decreased as the amount of GSE increased. In vitro analysis indicated that the antimicrobial activity of the PCL/GSE composite films increased as the GSE concentration increased, with a 5% concentration showing the strongest inhibitory activity against Listeria monocytogenes, with 5.8-log reduction in bacterial count. Application testing of the films was carried out for cheese packaging, and biodegradation of the samples was assessed via soil burial testing. Our findings confirmed the potential use of PCL/GSE composite films as biodegradable food packaging material with antimicrobial activity.

Characterization and Preservation Performance of Multilayer Film with Insect Repellent and Antimicrobial Activities for Sliced Wheat Bread Packaging.

A multilayer film containing star anise essential oil and thymol coating layers (SAEO and TH, respectively), with insect repellent and antimicrobial properties, has been developed using bar coating and adhesive lamination processes. Our previous study reported the in vitro activities of this polypropylene film (PP)/SAEO/polyethylene terephthalate film (PET)/TH/low-density polyethylene film (LDPE) multilayer film. The current study focused on demonstrating the morphological, optical, and mechanical properties of the film, and evaluating its in vivo activities when used as a bread packaging material. The developed film was 15.03% thicker and 1.86% less transparent than the control film (without active agent coating layers: PP/PET/LDPE). While the color values of the developed film were slightly different from the control film, both films appeared similar to the naked eye. The tensile strength in the developed film was somewhat lower than that of the control film, while both films had statistically comparable values for elongation at break. During storage of sliced bread packaged in the developed film, the film both deterred insects from approaching toward and impeded the growth of microorganisms in the bread. These results suggest the potential applicability of the developed film as an active food packaging material with insect repellent and antimicrobial activities. PRACTICAL APPLICATION: A multilayer film incorporated with insect repellent and antimicrobial coating layers was applied in sliced wheat bread packaging. The developed film effectively inhibited approaches of stored-product insects to packaged bread and growth of microorganisms on the bread surface. It can be used as an active food packaging material that improves the safety and shelf-life of foods.

Effect of green tea extracts on oxaliplatin-induced peripheral neuropathy in rats.

BACKGROUND: A common side effect of oxaliplatin is peripheral neurotoxicity. Oxidative stress to dorsal root ganglion (DRG) may be one of important pathogenic mechanisms. Green tea contains four polyphenol catechins, which are known to be potent antioxidants. The present work is aimed to determine whether green tea extracts have neuroproective or palliative effects on neurotoxicity symptoms induced by oxaliplatin. METHODS: We conducted behavioral tests including sensory and thermal thresholds, an electrophysiological study, and TUNEL staining to assess neurotoxicity during the experimental period using animal models. RESULTS: A total of 14 adult rats were randomly allocated into two groups. Oxaliplatin (4 mg/kg) with or without green tea (300 mg/kg orally once daily) was administered intraperitoneally twice per week for 6 weeks. At 4 and 6 weeks after oxaliplatin administration, sensory threshold values were significantly decreased and at 6 weeks after oxaliplatin administration, thermal threshold values were significantly increased in oxaliplatin-treated rats compared with those in rat treated with oxaliplatin and green tea extracts. The electrophysiological assessment, including sensory nerve conduction and H-reflex-related sensory nerve conduction velocity, revealed no significant changes in the two groups. TUNEL staining showed no significant difference in the number of apoptotic-featured cells between the two experimental groups in the DRG or peripheral nerves, but the number of apoptotic-featured cells in DRG was higher than that in sciatic nerves within each group. CONCLUSIONS: Green tea extracts may be a useful adjuvant to alleviate sensory symptoms after oxaliplatin administration, such as allodynia, but did not prevent morphometric or electrophysiological alterations induced by oxaliplatin.

Interexaminer reliability and accuracy of posterior superior iliac spine and iliac crest palpation for spinal level estimations.

OBJECTIVE: The purpose of this study was to compare the posterior superior iliac spine (PSIS) and the iliac crest as accurate anatomical landmarks for identifying spinal level. METHODS: This study was conducted in 2 stages. First, 4 examiners examined 60 patients and blindly identified iliac crest and PSIS levels, and the interexaminer reliability of PSIS and iliac crest palpation were then analyzed. Second, 4 examiners attached a radio opaque marker at presumed PSIS and iliac crest levels in 72 patients, and posteroanterior lumbar radiographs were then taken. Four examiners then confirmed PSIS and iliac crest levels after radiographically identifying the marker levels and checked the spinal level at which the spinous process or interspace was crossed by drawing a horizontal line drawn between radio opaque markers. RESULTS: The interexaminer reliability of palpation was significantly greater for PSIS level than for the iliac crest (P < .05). Spinal levels of estimated PSISs identified by palpation ranged from the L5-S1 interspace to the S2 spinous process, and the spinal levels of estimated iliac crest ranged from the L2-3 interspace to the L5 spinous process. CONCLUSIONS: Although PSIS palpation showed statistically higher interexaminer reliability than iliac crest level, clinicians should be cautious when applying this method as a measurement tool because estimated spinal level by palpation can be influenced inadvertently by examiner skill and anatomical variations.