No abstract

The objective of this study is to predict the variation in silver migration as a function of silver concentration, temperature and migration duration using polynomial model. Silver nanoparticles were produced via chemical reduction by using short-chain polyethylene glycol. Silver nanocomposites were prepared via two methods, namely, melt-blending and layer-by-layer self-assembling deposition. Surface response methodology was employed to investigate the effects of processing conditions, including processing method (melt blending and layer-by-layer coating) and silver nanoparticles concentration as well as migration conditions, including temperature, duration of contact, and contact media (water, 3% acetic acid, 10% ethanol, and apple juice), on the silver-ion migration of silver nanocomposites. Second-order polynomial regression models expressing silver-ion migrations as functions of the main numerical variables were significantly fitted (p<0.05) with a high coefficient of determination (R2>0.90). Migration time was considered as the most significant variable that affects silver-ion migration from silver nanocomposites. 

Today, the approach of using biodegradable food coatings and films is developing because, in addition to maintaining and improving the chemical, organoleptic, and physical properties of food (Bykov et al., 2017;Kocira et al., 2021), the result of biological decomposition of these types of packaging are non-toxic compounds such as water, carbon dioxide, and mineral compounds (Siracusa et al., 2008).

D. melanogaster is one of the most harmful citrus fruit flies having a large number of host plants. The molecular diagnostic method has been created for identification the D. melanogaster from another non-quarantine species Drosophila spp. The proposed method for differentiation is to use the mitochondrial DNA cytochrome oxidase I gene region 709-bp. We amplified samples of DNA with primers Droso-S391 and Droso-A381 by D. melanogaster, D. suzukii, and D. Simulans collections in the laboratory samples from many countries and contrasted with sequences of other GenBank Drosophila taxa. The findings of a polymerase chain reaction (PCR) based on DNA sequence polymorphisms showed that these primers accurately identify the area of the gene as well as the unique primers of Drosophila melanogaster.

Vegetables have a short shelf life, and because they are eaten fresh, it is necessary to use healthy and natural methods to increase their shelf life. The present study has investigated the effect of active packaging containing the active ingredient of thymol on the color and pH measurements, microbial evaluation, total mold and yeast count, and the sensory properties of seasonal salad during six-day storage refrigerator temperature. For this purpose, season salads were packed with oriented polypropylene (OPP) and low-density polyethylene (LDPE) films immersed in thymol essential oil for 1, 2, and 3 days. Results show that season salads packed with OPP and LDPE films immersed in thymol essential oil for three days had higher pH and lower mold and yeast count than control and other treatments. The mold and yeast count were significantly lower (p < 0.05) in a sample packed with OPP films containing essential oil compared to the LDPE/ thymol essential oil. The L* and -a * values decreased during storage time. The L* and -a * indices of season salads were lower in OPP and LDPE films immersed in thymol essential oil for three days than the neat and other groups. Sensory evaluation showed that immersion in thymol essential oil improved sensory attributes (p <0.05). The coated films, especially OPP, improved the color, reduced the number of mold and yeast, increased the shelf life, and improved the sensory attributes of season salads. Therefore, films treated with thymol essential oil can act as active packaging.