Stability of individual anthocyanins from black carrots stored in light and darkness - Impact of acylation.

Black carrot anthocyanins have gained increasing attention as natural coloring agent, owing to their higher stability than anthocyanins from berries. The stability has been attributed to their higher degree of acylation. This study investigated the impact of acylation on the stability of individual anthocyanins during storage in light and darkness. We hypothesized that the acylated anthocyanins would be more stable than the non-acylated ones. The major five anthocyanins were fractioned by semi-preparative HPLC and stored at pH 4.5 in light and darkness to investigate how acylation affected the stability. The stability was evaluated by absorption spectroscopy and mass spectrometry (MS). Two of the anthocyanins were non-acylated; 3-xylosyl(glucosyl)galactoside and cyanidin 3-xylosylgalactoside, and three were acylated; cyanidin 3-xylosyl(sinapolyglucosyl)galacto-side, cyanidin 3-xylosyl(feruloylglu-cosyl)galactoside, and cyanidin 3-xylosyl(coumaroyl-glucosyl)galactoside. Both methods (spectroscopy and MS) showed a clear effect of acylation when stored in light, but surprisingly the two non-acylated anthocyanins, showed higher stability than the three acylated ones.

Antibacterial activity of Hungarian varietal honeys against respiratory pathogens as a function of storage time.

Today, antibiotic therapies that previously worked well against certain bacteria due to their natural sensitivity, are becoming less effective. Honey has been proven to inhibit the biofilm formation of some respiratory bacteria, however few data are available on how the storage time affects the antibacterial effect. The activity of black locust, goldenrod, linden and sunflower honeys from three consecutive years (2020, 2021, 2022) was analyzed in 2022 against Gram-negative (Haemophilus influenzae, H. parainfluenzae, Pseudomonas aeruginosa) and Gram-positive (Streptococcus pneumoniae) bacteria using in vitro microbiological methods. After determining the physicochemical parameters of honey, broth microdilution was applied to determine the minimum inhibitory concentration of each honey type against each bacterium, and crystal violet assay was used to test their antibiofilm effect. The possible mechanism of action was explored with membrane degradation test, while structural changes were illustrated with scanning electron microscopy. Honeys stored for one or two years were darker than fresh honeys, while older honeys had significantly lower antibacterial activity. The most remarkable inhibitory effect was exerted by linden and sunflower honeys, and P. aeruginosa proved to be the most resistant bacterium. Based on our results, honey intended for medicinal purposes should be used as fresh as possible during a treatment.

Comparative study on effect of pomegranate peel powder as natural preservative and chemical preservatives on quality and shelf life of muffins.

This research aims to investigate the potential of utilizing pomegranate peel powder (PPP) as a natural preservative in muffin preparation. Pomegranate peel is a rich source of bioactive compounds, including phenolics, flavonoids, and tannins, which possess high antioxidant and antimicrobial properties. The In-Vitro antifungal activity of pomegranate peel powder (8% PPP), potassium sorbate (0.1% PS) and calcium propionate (0.5% CP) was assessed against Penicillium sp. and Aspergillus sp. using poison food technique. The PPP showed the anti-fungal activity by delaying the growth of microorganism on media plate similar to the PS and CP. The effect of utilization of PPP on quality characteristics of muffins were compared with the muffins with chemical preservatives (0.1% PS and 0.5% CP). The viscosity and specific gravity of batter significantly increased from 7.98 to 11.87 Pa s and 1.089-1.398 respectively on addition of 8% PPP. The optical microscopic structure of PPP added batter revealed the decrease in the number of air cells from 24 to 12 with radius range of 6.42-72.72 µm and area range of 511.03-15,383.17 µm2. The functional properties of flour with PPP had higher water absorption capacity, foaming stability, emulsification activity and emulsion stability than others. The addition of PPP significantly increase the weight (32.83 g), and decrease the height (31.3 mm), volume (61.43 cm3), specific volume (1.67 cm3/g) and baking loss (10.19%). The 418.36% increase in fibre content, 14.46% and 18.46% decrease in carbohydrates and energy value was observed in muffin with 8% PPP as compared to control respectively. The total phenols was increased from 0.92 to 12.5 mg GAE/100 g, total tannin from 0.2 to 8.27 mg GAE/100 g, In-vitro antioxidant activity by DPPH from 6.97 to 29.34% and In-vitro antioxidant activity by FRAP from 0.497 to 2.934 mg AAE/100 g in muffins added with 8% PPP. The muffin with PPP was softer than control and muffin with 0.1% PS. The addition of PPP resulted to improve in muffin texture but taste slightly bitter. During the storage of muffins at room temperature (27-30 °C), the moisture content of muffin with PPP was reduced from 17.04 to 13.23% which was higher than the rest of the treatments. Similarly, the hardness of sample with PPP was higher than the sample with 0.5% CP, but lowers than control and sample with 0.1% PS throughout the storage period. The results suggest that pomegranate peel powder can be successfully used as a natural preservative in place of chemical preservatives in muffins, to extend the shelf life. This study provides the opportunity to use PPP as functional ingredient and natural preservative in different bakery products.

Changes in amino acids, catechins and alkaloids during the storage of oolong tea and their relationship with antibacterial effect.

The storage process has a significant impact on tea quality. Few is known about effect of storage on quality of oolong tea. This study aimed to assess the effect of different storage times on the key chemical components of oolong tea by measuring changes in catechin, free amino acid, and alkaloid content. Variation in the main substances was determined by principal component analysis and heat map analysis. The results revealed notable effects of the storage process on the levels of theanine, epigallocatechin gallate (EGCG), and glutamine. These findings suggest that these compounds could serve as indicators for monitoring changes in oolong tea quality during storage. Additionally, the study observed an increase in the antibacterial ability of tea over time. Correlation analysis indicated that the antibacterial ability against Micrococcus tetragenus and Escherichia coli was influenced by metabolites such as aspartic acid, threonine, serine, gamma-aminobutyric acid, ornithine, alanine, arginine, and EGCG. Overall, this study presents an approach for identifying key metabolites to monitor tea quality effectively with relatively limited data.

"Age" of tea: The impact of long-term storage on the aroma of Tuo tea and age prediction.

This study investigates the dynamic changes in the aroma profile of Tuo tea during long-term storage, a process not well understood yet critical to the formation of aged tea's unique characteristics. Aroma profiling of Tuo tea samples stored for 2 to 25 years was conducted using sensory evaluation and the HS-SPME/GC × GC-QTOFMS technique, revealing a progressive transition from fresh, fruity, and floral scents to more stale, woody, and herbal notes. Among 275 identified volatiles, 55 were correlated with storage duration (|r| > 0.8, p < 0.05), and 49 differential compounds (VIP > 1, FC > 1.2, FC < 0.833, p < 0.05) were identified across three storage stages (2-4, 5-10, and 13-25 years). Furthermore, theaspirane, eucalyptol, o-xylene, and 1-ethylidene-1H-indene were selected as potential markers of Tuo tea aging, incorporating the implementation of a Random Forest (RF) model. Additionally, our model exhibited high accuracy in predicting the age of Tuo tea within a prediction error range of -2.51 to 2.84 years. This research contributes to a comprehensive understanding of the impact of storage time on tea aroma and aids in the precise identification of tea age.

Inhibitive effect of trehalose and sodium pyrophosphate on oxidation and structural changes of myofibrillar proteins in silver carp surimi during frozen storage.

This work investigated the cryoprotective effect of trehalose (TH) and sodium pyrophosphate (SPP) alone and in combination on myofibrillar protein (MP) oxidation and structural changes in silver carp surimi during 90 days of frozen storage (-20 °C). TH combined with SPP was significantly more effective than single TH or SPP in preventing MP oxidation (P < 0.05), showing a higher SH content (6.05 nmol/mg protein), and a lower carbonyl (4.24 nmol/mg protein) and dityrosine content (1280 A.U.). SDS-PAGE results indicated that TH combined with SPP did not differ significantly from TH and SPP in inhibiting protein degradation but was more effective in inhibiting protein crosslinking. Moreover, all cryoprotectants could stabilise the secondary and tertiary structures and inhibit unfolded and aggregation of MP, with the combination of TH and SPP being the best. It's worth noting that TH combined with SPP had a synergistic effect on inhibiting the decrease in α-helix content and gel-forming ability, and the increase in surface hydrophobicity. Overall, TH combined with SPP could significantly inhibited MP oxidation and structural changes in surimi during frozen storage and improve the gel-forming ability, which was significantly better than single TH or SPP.

Markers of sensory dynamics in phenols-rich virgin olive oils under optimal storage conditions.

Early changes in sensory quality of phenols-rich virgin olive oil (VOO) and their relationship with the chemical changes are less studied in the literature. Therefore, the objective of this study was to propose a predictive model of dynamics of sensory changes based on specific chemical markers. The evolution of the sensory quality of phenol-rich VOOs from Tuscan cultivars stored under optimal storage conditions (i.e., absence of light, no O2 exposure, low temperature) was investigated using a multi-step methodological approach combining sensory (official sensory analysis (so-called Panel Test), Descriptive Analysis and Temporal Dominance of Sensation) and chemical measurements. The sensory map from descriptive data was related to the phenolic and volatile profiles, measured using HPLC-DAD and HS-SPME-GC-MS, respectively. A predictive model of the sensory changes over storage based on chemical compounds was developed. Results showed that very early changes involving phenolic and volatile compounds profiles occur in VOOs stored under optimal storage conditions, which turn in changes in sensory properties evaluated by the official panel test, the descriptive analysis and the temporal dominance of sensation. Furthermore, a chemical marker of sensory dynamics of oils during storage was identified as the ratio between two groups of secoiridoids. The proposed model, supported by the mentioned chemical marker, has the potential of improving the control of sensory changes in phenols-rich virgin olive oils during storage in optimal conditions.

Metabolomics analysis of physicochemical properties associated with freshness degradation in frozen Antarctic krill (Euphausia superba).

This study aimed to determine the effect of different frozen temperatures during storage on the quality of Antarctic krill (Euphausia superba) and assess the change at the metabolite level via a combination of physicochemical property analysis, liquid chromatography-tandem mass spectrometry (LC-MS) based non-targeted metabolomics profiling. Regarding samples stored at -20 °C, the expressions of 7055 metabolites were elevated, while 2313 were downregulated. Lipids and lipid molecules had the highest proportion of differential metabolites. A total of 432 discriminatory metabolites with Kyoto Encyclopedia of Genes and Genomes (KEGG) IDs was obtained. We also observed that the concentrations of differential bitter free amino acids (FAAs) and oxidation products of arachidonic and linoleic acid increased. Moreover, as the storage temperature increased, the freshness, umami, and sweetness components were considerably reduced. Furthermore, results indicated that the color, pH and water-holding capacity (WHC) were potential indicators of quality deterioration, while inosinic acid was a probable biomarker for umami degradation of frozen Antarctic krill. In conclusion, this study demonstrates that storage at lower temperatures can be beneficial for maintaining the freshness of Antarctic krill from macro and micro perspectives.

Optimization of guar gum-based anti-browning coating for prolonging the shelf life of cut potatoes.

The impact of guar gum (GG), crude algae ethanolic extract (CAEE), and turmeric essential oil (TEO) incorporated edible coating formulations on the quality of cut potatoes was investigated at room temperature (27 ±â€¯3 °C, 70-85 % RH) storage using a rotatable central composite design. Besides, 30 % glycerol, 5 % calcium chloride, and 3 % ascorbic acid (w/w) were added to the coating solution as additives. The surface color, respiration rate, water vapor transmission rate, visible mold growth, and sensory analysis were assessed after seven days of storage. The inclusion of ascorbic acid and TEO in edible coating demonstrated a more effective delay in browning. The coated potatoes had lower OTR, CTR, and WVTR values for GG concentrations of 0.5 to 1 g/100 mL than the control. Compared to additives, higher concentrations of GG improved response parameters. The WVTR value of coated potatoes was significantly impacted by the interaction between CAEE and TEO with GG. Incorporating CAEE and TEO into the formulations of guar gum led to a reduction in the permeability of the coating to oxygen and water vapor. The seven days of extended shelf life compared to two days of control were observed with the optimized coating formulation. Furthermore, the application of the coating treatment proved effective in preventing enzymatic browning and creating a barrier against moisture and gases, contributing to prolonged freshness during extended storage periods.

The Effect of Hyperbaric Storage on the Nutritional Value and Retention of Certain Bioactive Proteins in Human Milk.

Human milk (HM) contains the essential macronutrients and bioactive compounds necessary for the normal growth and development of newborns. The milk collected by human milk banks is stored frozen and pasteurized, reducing its nutritional and biological value. The purpose of this study was to determine the effect of hyperbaric storage at subzero temperatures (HS-ST) on the macronutrients and bioactive proteins in HM. As control samples, HM was stored at the same temperatures under 0.1 MPa. A Miris HM analyzer was used to determine the macronutrients and the energy value. The lactoferrin (LF), lysozyme (LYZ) and α-lactalbumin (α-LAC) content was checked using high-performance liquid chromatography, and an ELISA test was used to quantify secretory immunoglobulin A (sIgA). The results showed that the macronutrient content did not change significantly after 90 days of storage at 60 MPa/-5 °C, 78 MPa/-7 °C, 111 MPa/-10 °C or 130 MPa/-12 °C. Retention higher than 90% of LYZ, α-LAC, LF and sIgA was observed in the HM stored at conditions of up to 111 MPa/-10 °C. However, at 130 MPa/-12 °C, there was a reduction in LYZ and LF, by 39 and 89%, respectively. The storage of HM at subzero temperatures at 0.1 MPa did not affect the content of carbohydrates or crude and true protein. For fat and the energy value, significant decreases were observed at -5 °C after 90 days of storage.

Preharvest Elicitors as a Tool to Enhance Bioactive Compounds and Quality of Both Peel and Pulp of Yellow Pitahaya (Selenicereus megalanthus Haw.) at Harvest and during Postharvest Storage.

Yellow pitahaya is a tropical fruit that has gained popularity in recent years. Natural elicitors are compounds that can stimulate the resistance and quality of fruits. The objective of this study was to evaluate the effects of natural elicitors, methyl salicylate (MeSa), methyl jasmonate (JaMe), salicylic acid (SA) and oxalic acid (OA) at concentrations of 0.1 mM (MeSa and JaMe) and 5 mM (SA and OA), applied to the yellow pitahaya fruits under greenhouse conditions. After full blossom, four applications were made with a frequency of 15 days. At the time of harvest and after storage, the following variables were evaluated: firmness (whole fruit), total soluble solids (TSS), total acidity (TA), phenolics and carotenoids (in the pulp), while phenolics, carotenoids, macronutrients and micronutrients were determined in the peel. The results showed MeSa advanced the fruit maturation, according to higher TSS, lower TA and firmness than MeJa-treated fruits, for which a delayed ripening process was shown. All treatments induced a higher polyphenolic concentration during storage. Regarding the alternative use of the peel as a by-product, the application of natural elicitors significantly increased the content of polyphenols, carotenoids, macronutrients and micronutrients in the peel, especially MeSa, which can be used as a bioactive compound in the food industry. In conclusion, the results indicate that natural elicitors can be an alternative to improve the quality and shelf life of yellow pitahaya fruits.

Refrigerated storage stimulates isoflavone and γ-aminobutyric acid accumulation in germinated soybeans.

This study aims to investigate the quality changes of germinated soybeans during refrigerated storage (4 °C), with an emphasis on the stimulatory effect of refrigeration on their special functional compounds. After germinating for two days, germinated soybeans were stored at 4 °C for seven days, while the germinated soybeans stored at 25 °C served as control group. The results showed that refrigerated storage significantly affected the physiological changes in germinated soybeans. The weight loss rate, browning rate, malondialdehyde (MDA) content and H2O2 content all decreased dramatically during refrigerated storage compared to the control group. The total phenolic and total flavonoid contents of germinated soybeans under refrigeration exhibited a trend of increasing and then decreasing over time. Additionally, during refrigerated storage, the total isoflavone content reached a peak of 8.72 g/kg on the fifth day, in which the content of daidzein and glycitin increased by 45% and 49% respectively, when compared with the control group. Moreover, the content of γ-aminobutyric acid (GABA) peaked on the first day, and kept a high level during storage. In which, the refrigerated group was 2.35-, 2.88-, 1.67-fold respectively after storage for three to seven days. These results indicated that refrigeration stimulated the biosynthesis of isoflavones and GABA in germinated soybeans during storage. More importantly, there was a sequential difference in the timing of the stimulation of the two functional components under refrigeration.

1-MCP treatment improves the postharvest quality of Jinxiu yellow peach by regulating cuticular wax composition and gene expression during cold storage.

This study aimed to analyze the effect of 1-methylcyclopropene (1-MCP) treatment on the postharvest quality, epidermal wax morphology, composition, and gene expression of Jinxiu yellow peach during cold storage. The results showed that 1-MCP treatment could maintain the postharvest quality of peach fruit as compared to control (CK) during cold storage. The wax crystals of peach fruit were better retained by 1-MCP, and they still existed in 0.6 and 0.9 µL/L 1-MCP treated fruit at 36 days. The total wax content in all the fruit increased first and then decreased during cold storage. Meanwhile, n-alkanes and primary alcohols were the main wax components. Compared to CK, 1-MCP treatment could delay the reduction of wax content during cold storage. The correlation analysis indicated that the postharvest quality of yellow peach was mainly affected by the contents of fatty acids and triterpenoids in cuticular wax. The transcriptomics results revealed PpaCER1, PpaKCS, PpaKCR1, PpaCYP86B1, PpaFAR, PpaSS2, and PpaSQE1 played the important roles in the formation of peach fruit wax. 1-MCP treatment upregulated PpaCER1 (18785414, 18786441, and 18787644), PpaKCS (18774919, 18789438, and 18793503), PpaKCR1 (18790432), and PpaCYP86B1 (18789815) to deposit more n-alkanes and fatty acids during cold storage. This study could provide a new perspective for regulating the postharvest quality of yellow peach in view of the application of cuticular wax. PRACTICAL APPLICATION: 'Jinxiu' yellow peach fruit is favorable among consumers because of its high commercial value. However, it ripens and deteriorates rapidly during storage, leading to serious economic loss and consumer disappointment. The effect of 1-methylcyclopropene (1-MCP) treatment on the postharvest quality, epidermal wax morphology, composition, and genes regulation of 'Jinxiu' yellow peach during cold storage was assessed. Compared to control, 1-MCP treatment could retain the storage quality of yellow peach by affecting cuticular wax composition and gene expression. This study could provide new perspective for regulating the postharvest quality of yellow peach in view of the application of cuticular wax.

Effects of 2'-fucosyllactose on the viability of starter cultures and Bifidobacterium strains of human origin in yogurt during refrigerated storage.

2'-Fucosyllactose (2'-FL) is postulated to provide health benefits and promote the growth of probiotics. This work was undertaken to study the effects of 2'-FL on the viability of starter cultures and Bifidobacterium strains of human origin in yogurt during refrigerated storage. Yogurts were produced containing 2'-FL (0 or 2 g/L) and Bifidobacterium strains of human origin (Bifidobacterium longum subsp. longum BB536 or Bifidobacterium longum subsp. infantis ATCC 15697) at a concentration of at least 109 CFU/mL. All yogurts were stored at 4°C for 5 weeks. Results showed that 2'-FL was stable in yogurts for at least 5 weeks of cold storage, and the addition of 2'-FL did not significantly alter yogurt fermentation parameters, associated metabolites, and the viability of mixed yogurt starter cultures and Bifidobacterium strains (p > 0.05). The addition of bifidobacteria had a negative impact (p < 0.05) on the survival rate of starter cultures, Streptococcus thermophilus and Lactobacillus delbureckii subsp. bulgaricus. Meanwhile, it is difficult to maintain a high survival rate of bifidobacteria in final yogurt products, and the addition of 2'-FL could not enhance the viability of bifidobacteria. B. longum BB536 survived at a level higher than 106 CFU/g for 28 days, while B. infantis ATCC15697 maintained this level for only 7 days. In summary, this study has shown the impact of 2'-FL and bifidobacterial species on yogurt properties, and results suggest that it is promising to use 2'-FL in yogurt products as a prebiotic. PRACTICAL APPLICATION: Yogurt is known for its beneficial effects on human health and nutrition. This study reported the production of symbiotic yogurt containing bifidobacteria and 2'-fucosyllactose (2'-FL) as a functional food for specified health uses. The viability of yogurt starter cultures and probiotic bifidobacterial strains was analyzed in this study. Moreover, this research demonstrated that 2'-FL could be added to yogurt without affecting the characteristics of yogurt significantly.

Effect of the Drying Method and Storage Conditions on the Quality and Content of Selected Bioactive Compounds of Green Legume Vegetables.

This study aimed to determine the effect of the drying method (freeze-drying, air-drying), storage period (12 months), and storage conditions (2-4 °C, 18-22 °C) applied to two legume species: green beans and green peas. The raw and dried materials were determined for selected physical parameters typical of dried vegetables, contents of bioactive components (vitamin C and E, total chlorophyll, total carotenoids, ß-carotene, and total polyphenols), antioxidative activity against the DPPH radical, and sensory attributes (overall quality and profiles of color, texture, and palatability). Green beans had a significantly higher content of bioactive components compared to peas. Freeze-drying and cold storage conditions facilitated better retention of these compounds, i.e., by 9-39% and 3-11%, respectively. After 12 months of storage, higher retention of bioactive components, except for total chlorophyll, was determined in peas regardless of the drying method, i.e., by 38-75% in the freeze-dried product and 30-77% in the air-dried product, compared to the raw material.

The effects of Juniperi fructus essential oil and vacuum packing on the shelf life of rainbow trout fillets during storage at 2±1°C.

We hypothesized that the combined effect of vacuum packaging and Juniperi fructus essential oil addition would increase shelf life. Six different treatments were tested. The effects of the different concentrations of J. fructus essential oil (0%, 0.3% and 0.6%) and packing method (non-vacuum and vacuum) on the fish (Oncorhynchus mykiss) fillets of stored 4±1 °C were investigated in terms of its microbiological (mesophilic aerobic bacteria and yeast-mold), chemical (pH,  total volatile alkaline nitrogen (TVB-N), thiobarbituric acid (TBA value)) and sensory quality. The results showed that J. fructus essential oil had a positive significant effect on quality parameters (p<0.05). In conclusion, based primarily on sensory, TVB-N and mesophilic bacteria data the shelf-life of fresh rainbow trout was 4 days (non-vacuum packaged), 13 days (vacuum packaged), 19 and 28 days treated with J. fructus oil (0.3 and 0.6%, v/w) under vacuum packaged, respectively. J. fructus essential oil application and vacuum packaging; extended the shelf life of fish fillets by an average of 15 days. The combined use of J. fructus essential oil and packaging techniques could form the basis for new studies.

Effect of accelerated aging on shelf-stability, product loss, sensory and biochemical characteristics in 2 lower quality beef cuts.

The aim of this study was to determine the impact of accelerated aging (AA) on shelf stability, product loss, sensory and biochemical characteristics of 2 lower quality beef cuts. Triceps brachii (TB) and semimembranosus (SM) were collected and fabricated from 10 USDA Choice beef carcasses and assigned to 1 of 6 treatments: 3 d cooler aged (control), 21 d cooler aged, AA 49 °C for 2 h, AA 49 °C for 3 h, AA 54 °C for 2 h, and AA 54 °C for 3 h. The results showed that AA can decrease APC counts on steak surface and in purge and redness, but increase lightness and product loss of the steaks (P < 0.01). Lower shear force was also found for AA steaks compared to those from the control (P < 0.01), with the AA 54 °C treatments being comparable to 21 d cooler aging. However, the trained sensory panel determined AA steaks were less juicy and flavorful than those from the control and 21 d cooler aged samples (P < 0.05). There was no off-flavor detected in AA steaks though lipid oxidation was higher in AA samples than those in the control steaks (P < 0.01). The AA treatments stimulated cathepsin activity (P < 0.05), which may have enhanced the solubilization of stromal proteins and led to a different troponin-T degradation pattern compared to those from the 21 d aged samples (P < 0.01). Although AA is an economical and time-efficient method to increase tenderness of lower-quality beef cuts, further research is needed to determine strategies to mitigate the decrease in juiciness from AA treatments.

Near-freezing temperature suppresses avocado (Persea americana Mill.) fruit softening and chilling injury by maintaining cell wall and reactive oxygen species metabolism during storage.

To enhance the postharvest quality of avocado (Persea americana Mill.) fruit, this study investigates alterations in cell wall metabolism and reactive oxygen species (ROS) metabolism during near-freezing temperature (NFT) storage, and explores their impact on fruit softening. The fruit was stored at 25 °C, 5 °C, 2 °C, and NFT, respectively. NFT storage retarded firmness loss and chilling injury in comparison with 25 °C, 5 °C, and 2 °C. NFT storage delayed the decrease of ionic-soluble pectin (ISP) and cellulose (CLL) contents by suppressing cell wall degradation enzyme activities. Correlation analysis showed that cell wall degradation enzyme activities were positively correlated to rates of ethylene release and respiration. Moreover, NFT storage maintained higher levels of DPPH and ABTS scavenging abilities, activities of superoxide dismutase, peroxidase, and catalase, as well as ascorbate-glutathione cycle (ascorbic acid, glutathione, glutathione disulfide, ascorbate peroxidase, cycle-related enzymes), thereby inhibited the increase of ROS content, malondialdehyde content, and cell membrane permeability. Fruit firmness and chilling injury were correlated with the contents of hydrogen (H2O2), superoxide anion (O2.-), ISP, and CLL. These results suggested that NFT could suppress fruit softening and chilling injury by inhibiting cell wall degradation through delaying respiration and ethylene production and suppressing ROS production via activation of antioxidant systems, thereby maintaining quality and prolonged storage life during avocado fruit storage.

Corn cob nanocellulose packaging for increasing the shelf life of food products.

Studies were carried out to develop eco-friendly Packaging material for the extended shelf-life of food products. The current study sought to improve the coated bioactive film's hydrophobicity and antimicrobial properties by preparing active packaging based on biodegradable Poly Lactic Acid (PLA) containing 1 wt% Nanocellulose (NC) and various loadings of essential oil-prepared nanocomposites. Nanocellulose (NC) from Maize Cob was used as filler in the synthesis of nanopolymers enriched with Thyme oil, Cinnamon oil, clove oil, and Rosemary oil. Characterization of nanopolymer-coated bags and their effect on enhancing the shelf-life of food products in different temperature conditions was also studied. The fabricated nanocomposite and nanocellulose were characterized using FTIR, SEM, XRD, Contact angle, TGA, and Tensile mechanical properties. The fabricated nanocomposite-coated paper cum bag shows good hydrophobic properties as well as antimicrobial and insecticidal properties. The results showed that adding essential oils and dispersing nanocellulose to the PLA matrix strengthened its mechanical qualities as well as its efficacy for biodegradation and antimicrobial properties. The current work provides extremely promising materials for future applications in food packaging applications using sustainable nanocomposite-based biodegradable and antimicrobial coated paper cum bags.

High performance poly(L-lactic acid)-based film by one-step synthesis of poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) for efficient preservation of yogurt storage.

Biodegradable poly(L-lactic acid) (PLLA) has seldom used for dairy packaging due to medium permeability and brittleness. Novel PLLA copolymers, poly (L-lactic acid-co-butylene itaconate-co-glycolic acid) (PLBIGA), were developed by integrating glycolic acid (GA) and poly(butylene itaconate) (PBI) into PLLA's structure using low molecular weight PLLA as a key initiator. Then, packaging materials with better barrier and mechanical properties were obtained by blended PLBIGA with PLLA. Both PLLA/PLBIGA films and polyethylene nylon composite film (PE/NY) were used for stirred yogurt packaging and storage at 4 °C for 25 days. Results revealed that yogurt packed by PLLA/PLBIGA films maintained stabler water-holding capacity, color, and viscosity over the storage period. Moreover, the integrity of the gel structure and the total viable count of lactic acid bacteria in yogurt packaged in PLLA/40-PLBIGA8 were also found to be superior to those in PE/NY packages, highlighting its eco-friendly advantages in dairy packaging.