Days Of Cold Storage Research Articles

A comparison of culture and cooling for the short term preservation of in vivo derived dromedary camel embryos of varying morphological quality

Despite recent advancements in the cryopreservation of dromedary camel embryos, widespread application of the technique is still limited by the need for specialised vitrification equipment and supplies. Temporary, liquid-phase embryo storage methods provide a useful tool for short-term preservation of camel embryos.In the current study, we compared the use of in vitro embryo culture with cold liquid storage in order to maintain both high- (Grade 1- Excellent and 2-Good) and low- (Grade 3- Moderate and 4-Poor) morphological grade Day-7 dromedary camel embryos in vitro for up to 3 days. Embryos were either cooled and placed in Hams-F10 medium supplemented with HEPES and 10% FBS and then kept at 4 °C; or placed in Hams-F10 supplemented with sodium bicarbonate and 10% FBS and then cultured in a humidified atmosphere of 6% CO2 at 37 °C before being assessed for viability at 24 h. In high-morphological grade embryos, both cold storage and culture supported 100% viability (maintenance of normal morphology) over this period (Cooled n = 22, Cultured n = 20). In low-morphological grade embryos, culture supported higher viability (16/18, 88.9%) than did cooling (4/18, 22.2%). We then evaluated the effect of up to 3 days of cold storage or culture on embryo morphological grade, diameter, and developmental competence following embryo transfer. High-grade embryos were divided between culture and cold storage; low-grade embryos were evaluated only after culture. Over 3 days of culture, both high- and low-grade embryos tended to either maintain or improve upon their initial morphological score (P < 0.05) and increased in diameter (P < 0.001). Embryos subjected to cooling tended to have reduced morphological scores by 48 h of storage and decreased in diameter by 72 h (P < 0.05). No significant influence of storage method (cooling vs. culture), duration (24–72 h), or embryo grade (high vs low) was observed on pregnancy establishment at Day-60 (22.2%–57.2% pregnancy rates for all treatments). Overall, rates of pregnancy establishment were similar for transferred cultured (n = 45) and cooled (n = 45) embryos (pregnancy rates at Day 18, 48% vs 51.1%; at Day 60, 37.7% vs 37.7%). Rates of embryonic loss also were similar (22.7% vs 26%).In conclusion, whilst similar rates of pregnancy and pregnancy loss were observed following the transfer of both cooled and cultured embryos held in vitro for up to 3 days, amongst the two methods, only embryo culture appears to provide a means of effectively preserving Day- 7 dromedary camel embryos with reduced morphological values in vitro. Considering these embryos appear to show poor tolerance to the cooling procedure and are unlikely candidates for vitrification, embryo culture may provide an effective method for deriving pregnancies from low-morphological grade embryos when immediate transfer is not possible on the day of flushing.

Development of a Novel Beverage with Cactus Juice (Opuntia Ficus Indica) and date Palm sap (Phoenix Dactylifera L)

This study aimed to evaluate the possibility to produce a beverage combining Opuntia ficus Indica juice (OFIJ) and date palm sap (Phoenix dactylifera L.) (DPS). Beverages (B1, B2, B3) were formulated by mixing the juice and date palm sap at different ratios (40:60%, 30:70%, 20:80%) whereas OFIJ and DPS were considered as the controls. Sensory evaluation using 5-point hedonic scale was performed and showed that the control DPS was the most appreciated in term of aftertaste and overall acceptability. Among the formulated beverages B3 is more appreciated than B2, followed by B1. Physico-chemical analysis showed that the sedimentation and serum separation increase considerably after 28 days of cold storage traducing the instability of beverages. Microbial analysis carried out during 42 days of cold storage revealed the absence of total coliforms, Staphylococcus and Escherichia coli for all drinks and that after 28 days of storage the beverages cannot be consumed.

Microbial inhibition and shelf-life extension of longan (Dimocarpus longan) juice by UV radiation

This study aimed to investigate the effects of UV radiation at different doses (0–149.8 J/cm2) and pasteurization process (72 ± 1 °C, 1 min) on the quality preservation of longan juice. Longan juice was inoculated with Escherichia coli and subjected to UV and pasteurization process. UV-149.8 J/cm2, and pasteurized longan juice samples had higher log reduction values of total microbial (2.80 and 3.63), yeast/mold (4.14 and 4.56), and E. coli (2.76 and 4.13) log CFU/mL, respectively, compared to untreated control and other UV treated samples. The first order kinetic model potentially inhibited total microbial count, yeast/molds and E. coli in UV-149.8 J/cm2 sample. pH, total solids, total acidity, and turbidity showed no difference in UV and pasteurized samples. However, color values were affected in pasteurized sample than the UV treatments. Total phenolic content (TPC), total flavonoid content (TFC) and antioxidant (DPPH and FRAP) values were highest in untreated control, followed by the UV-74.88 J/cm2 than that of UV-149.8 J/cm2 and pasteurized samples. Based on the highest bioactivity, UV-74.88 J/cm2 and pasteurized samples were compared for quality changes during 15 days of storage at 4 °C. The selected UV-74.88 J/cm2 sample had higher TPC, TFC, DPPH, and FRAP values than the pasteurized sample up to 12 days of cold storage. Additionally, total plate count and yeast/mold were lowest in UV-74.88 J/cm2 sample in comparison with untreated control. Color values were stable in UV-74.88 J/cm2 sample, compared to pasteurized sample. Pasteurized longan juice showed no growth of yeast/mold during the entire storage period. Therefore, shelf life of UV-74.88 J/cm2 sample was prolonged to 12 days compared to the control sample that became unacceptable after 6 days during storage at 4 °C. UV treatment of longan juice could be considered a promising non-thermal additive free technology for reducing microbial load, improving quality characteristics, and extending shelf life.

Optimal Preharvest Melatonin Applications to Enhance Endogenous Melatonin Content, Harvest and Postharvest Quality of Japanese Plum

Plum is one of the most produced stone fruits worldwide. Melatonin is an environmentally eco-friendly substance that, in low concentrations, activates defence systems against biotic and abiotic stresses. This substance is considered a tool that could increase fruit quality. This study aimed to evaluate the impact of different preharvest foliar applications with different melatonin concentrations (0.1, 0.3, 0.5 mmol L−1) to enhance melatonin content and shelf life of ‘Primetime’ plum. To this purpose, two and three applications were carried out at different critical stages of fruit growth. Different quality characteristics such as size, colour, titratable acidity, total soluble solids, ripening index, respiration rate, ethylene production rate, anthocyanins and total antioxidant activity, as well as endogenous melatonin content, were tested at harvest and after 40 days of cold storage. Results showed that ‘Primetime’ plums that received 3 applications of 0.5 mmol L−1 enhanced endogenous melatonin content at harvest and showed less softening, delayed darkening, higher anthocyanin concentration and total antioxidant activity after 40 days of storage. Therefore, the concentration of 0.5 mmol L−1 melatonin in 3 applications was effective in improving the quality of ‘Primetime’ plums.

Postharvest abscisic acid treatment modulates the primary metabolism and the biosynthesis of t-zeatin and riboflavin in zucchini fruit exposed to chilling stress

Abscisic acid (ABA) plays an important role in the regulation of several stress responses such as drought, high salinity and low temperature being also proved as a key phytohormone for the acquisition of postharvest cold tolerance in zucchini fruit. Therefore, it would be of great interest to unravel the mechanisms implicated in the ABA response, using a metabolomic approach. The aim of this work has been to use a combination of metabolomic tools to identify the main metabolic pathways involved in ABA-mediated regulation of chilling tolerance in zucchini fruit. As a result of this study, it was found that ABA modulates the primary metabolism inducing the accumulation of some sugars, organic acids such as succinic acid and amino acids including histidine, serine, phenylalanine, glutamic acid and γ-aminobutyric acid, and that are involved in low-temperature tolerance. ABA treatment also activates the t-zeatin and riboflavin biosynthesis during the first days of cold storage which can be important signals in the ABA-mediated cold response to induce tolerance in zucchini fruit.

Use of novel postharvest Aloe vera gel coating for suppression of ripening changes in Asian pears during long‐term cold storage

SummaryThe impact of Aloe vera gel (AVG) coatings (0%, 25%, 50% and 75%) was evaluated on the ripening‐related quality parameters in ‘Patharnakh’ pear fruit during long‐term cold storage (0 ± 1 °C and 90–95% RH). Results showed that AVG coating extended the storage life of fruit by minimising mass loss, decay index, respiration rate, polyphenol oxidase activity, softening enzyme activities like pectin methylesterase (PME) polygalacturonase (PG) and cellulase and maintaining the preliminary sensory quality (SQ), firmness, soluble solid content (SSC), total phenols, titratable acidity (TA) over the control. Among all AVG treatments, 75% AVG treatment was found most promising for suppressing mass long, lowering respiration rate and preserved overall fruit quality up to 60 days of cold storage in ‘Patharnakh’ pear fruit. Hence, AVG proved as an alternative to non‐edible coatings for extending the pear's marketable span and cutting down the adverse effects of health and environmental hazards.

Comparative Study of some Characteristics for Whey Cheese Produced by Heat Acid Coagulation

In the current study sweet whey obtained from white soft cheese was used for processing of Ricotta cheese using heat treatment with acid and Best Ricotta which manufactured by heating without addition of acid. Cheese samples were analyzed for some physicochemical analysis (moisture, total solids, pH, protein, yield and hardness) and organoleptic characteristics including (Appearance, texture, flavor, color, and overall acceptability) during 7 days of storage at 4±1ºc. It was found that the moisture content of Ricotta cheese was76.50% which was lower than that of Best ricotta 79.266%, the total solid of Best ricotta cheese was 17.733 %, while for Ricotta cheese was 21.50 %. Ricotta cheese characterized by lower pH value of 5.48 and higher acidity, protein contain, yield and hardness 0.103 %, 14.2%, 8.7% and 6g as compared to Best Ricotta cheese which were 6.40, 0.054 %, 12.26%, 6.49% and 3.66 g respectively at the first day of cold storage. It was noted that with the prolonged of the storage time, there was an increase in the values of some characteristics, including the percentage of total solids, acidity and hardness, while there was a decrease in the values of pH, moisture and protein percentage. Ricotta cheese gets the highest score by sensory panelists for the texture and appearance and unlike for, flavors and color than the Best Ricotta. Those degrees decreased slightly during the storage period.

Effect of Ozon Treatment on Shelf-Life of Poultry Meat in the Logistic Chain

Abstract A study was carried out to determine the influence of ozon treatment on the shelf-life of poultry meat. The following doses of gaseous ozone were used: 0 ppm for 0 min, 10 ppm for 1 min, 10 ppm for 5 min, 10 ppm for 15 min, 100 ppm for 1 min, 100 ppm for 5 min, and 100 ppm for15 min. Treated and untreated samples were stored at 4°C for a maximum of 3 days and microbiologically examined on the 1st, 2nd and 3rd day of cold storage. The textural properties and water content were also analyzed. The present study showed that the most desirable color change was recorded after the 3rd day of storage, on the samples treated with gaseous ozone of 10 ppm for 15 min. Regardless of exposure time and the gas dose used, ozone has been shown to effectively reduce meat hardness. Although the analyzes performed had non-significant effects on water content and microbiological load during post-treatment storage at 4 °C, our findings confirmed the effectiveness of the ozone gas used on extending shelf life of the examined poultry meat by influencing their texture profile and color parameters.

Utilization of blueberry-based ingredients for formulating a synbiotic Petit Suisse cheese: Physicochemical, microbiological, sensory, and functional characterization during cold storage

Blueberry by-products contain functional compounds and can be utilized to develop high-value ingredients for the formulation of functional dairy snacks. Petit Suisse cheese is a suitable matrix for adding innovative ingredients. This study aimed to develop and characterize two blueberry-based ingredients, a concentrated syrup, and a lyophilized bagasse powder, and incorporate them into a synbiotic Petit Suisse cheese containing probiotics and inulin. Six phenolic compounds were found in both ingredients, and the blueberry bagasse powder showed the highest bioactive content and antioxidant activity. The physicochemical, microbiological, and functional characteristics of the Petit Suisse formulations were analyzed during 21 days of cold storage, and proximal and sensory parameters were also assessed. The addition of blueberry-based ingredients increased the fiber content and affected the viscosity and syneresis parameters. The acidity and probiotic viability remained stable during storage. Bioactive and antioxidant features were improved up to 14 days, after which they began to decline slightly. The formulation with 10 g/100 g of blueberry syrup and 2 g/100 g of blueberry bagasse showed the highest sensory scores. These findings demonstrate the feasibility of using blueberry-based ingredients to manufacture synbiotic dairy snacks based on Petit Suisse cheese, enhancing their nutritional and functional properties.

Aloe vera Oil-Added Agar Gelatin Edible Films for Kashar Cheese Packaging.

In recent years, there has been a growing interest in edible and biodegradable films due to their sustainability, environmental friendliness, and their functionality. In this work, Aloe vera oil-added agar-gelatin films were prepared and characterized in terms of water content, degree of swelling, water solubility, antioxidant activity, and antimicrobial activity. The possibility of using these edible films for Kashar cheese packaging during cold storage was investigated. Physical, chemical, and microbiological properties of the packaged cheese samples were examined for 20 days of cold storage at 4 °C. A. vera oil-added films were found to have antibacterial activity against Escherichia coli and Staphylococcus aureus and antifungal activities against Aspergillus niger and Candida albicans. A. vera oil-added films showed high antioxidant activities, increasing with the increasing A. vera oil percentage in the formulation. The current study showed that at the end of 20 days of storage period, bacterial growth in A. vera oil-incorporated film-covered samples was 2.30 log CFU/g lower than the control samples, and the amount of yeast and mold in A. vera oil-added film-covered samples was 3.37 log CFU/g lower than control samples. This shows the efficiency of A. vera oil-incorporated agar-gelatin films during the refrigerated storage period. Our data evidenced the positive effect of A. vera oil-added agar-gelatin films on Kashar cheese packaging as an innovative and sustainable technique to maintain cheese quality and prevent food loss during storage.

Characterization of Physicochemical, Biological, and Chemical Changes Associated with Coconut Milk Fermentation and Correlation Revealed by 1H NMR-Based Metabolomics.

Fermentation of milk enhances its nutritional and biological activity through the improvement of the bioavailability of nutrients and the production of bioactive compounds. Coconut milk was fermented with Lactiplantibacillus plantarum ngue16. The aim of this study was to evaluate the effect of fermentation and cold storage for 28 days on physicochemical characteristics, shelf life, and antioxidant and antibacterial activities of coconut milk as well as its proximate and chemical compositions. The pH of fermented milk decreased from 4.26 to 3.92 on the 28th day during cold storage. The viable cell count of lactic acid bacteria (LAB) in fermented coconut milk was significantly increased during fermentation and cold storage period (1 to 14 days), reaching 6.4 × 108 CFU/mL, and then decreased significantly after 14 days to 1.6 × 108 CFU/mL at 28 days. Yeast and molds in fermented coconut milk were only detected on the 21st and 28th days of cold storage, which ranged from 1.7 × 102 to 1.2 × 104 CFU/mL, respectively. However, the growth of coliforms and E. coli was observed on the 14th until the 28th day of cold storage. The fermented coconut milk demonstrated strong antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Cronobacter sakazakii, Bacillus cereus, and Salmonella typhimurium compared to fresh coconut milk. Fermented coconut milk had the greatest 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) values, with 67.1% and 61.961 mmol/g at day 14 of cold storage, respectively. Forty metabolites were detected in fermented and pasteurized coconut milk by proton nuclear magnetic resonance (1H NMR) metabolomics. The principal component analysis (PCA) showed clear difference between the fermented and pasteurized coconut milk as well as the studied cold storage days. The metabolites responsible for this variation were ethanol, valine, GABA, arginine, lactic acid, acetoin, alanine, phenylalanine, acetic acid, methionine, acetone, pyruvate, succinic acid, malic acid, tryptophan, uridine, uracil, and cytosin, which were higher in fermented coconut milk. However, sugars and other identified compounds were higher in fresh coconut milk. The findings of this study show that fermentation of coconut milk with L. plantarum ngue16 had high potential benefits to extending its shelf life and improved biological activities as well as other beneficial nutrients.

OBSERVATION OF THE SUITABILITY OF SINGLE STRAINS OF STREPTOCOCCUS THERMOPHILUS AND LACTOBACILLUS DELBRUECKII SUBSP. BULGARICUS ISOLATED FROM LOCAL DAIRY SOURCES IN TURKEY AS YOGURT STARTER COMBINATIONS

The present study investigated the suitability of combinations one Streptococcus thermophilus and five Lactobacillus delbrueckii subsp. bulgaricus isolates for industrial yogurt productions. The isolates were selected after a detailed pre-screening procedure based on acidification performances, production of volatile aroma compounds, texture developing properties and sensory evaluations of yogurts made from single cultures. The fermentation profiles of the combinations were investigated by monitoring the small oscillatory rheological parameters and pH reductions during fermentation. The variations in some physical, chemical and organoleptic characteristics of the yogurt samples were also monitored during cold storage at 4 ºC for 21 days. Results indicated that all the combinations reduced the milk acidity to pH 4.6 within 4-5 hour at 43 ºC. Gelation profiles of the samples were close to each other (close tan δ values) with different elastic (G') and loss (G") moduli, indicating that similar chemical bondings took place in gel formation with different levels. All the samples showed a shear-thinning non-Newtonian flow behavior. Total number of starter bacteria was higher than 6 log cfu/mL in each sample after 21 days of storage. The post-acidification rates were also limited (between 4.21-4.37 after 21 days of cold storage). Untrained sensory evaluation panel found no marginal differences between the samples regarding appearance, body and texture, and aroma and flavor of the samples. To conclude, the combinations examined in this study were found to be suitable for commercial yogurt productions.

Impact of Novel Active Layer-by-Layer Edible Coating on the Qualitative and Biochemical Traits of Minimally Processed 'Annurca Rossa del Sud' Apple Fruit.

The color changes brought on by the enzymatic interactions of phenolic compounds with released endogenous polyphenol oxidase and the penetration of oxygen into the tissue has a significant impact on the commercialization of fresh-cut fruit, such as apples. This process causes a loss of quality in fresh-cut apples, resulting in browning of the fruit surface. By acting as a semipermeable barrier to gases and water vapor and thus lowering respiration, enzymatic browning, and water loss, edible coatings can provide a chance to increase the shelf life of fresh-cut produce. In this study, the effect of edible coatings composed of carboxymethylcellulose (CMC, 1%), sodium alginate (SA, 1%), citric acid (CA, 1%), and oxalic acid (OA, 0.5%) on fresh-cut 'Annurca Rossa del Sud' apple was studied. Four formulations of edible coatings, A. SA+CMC, B. SA+CMC+CA, C. SA+CMC+OA, and D. SA+CMC+CA+OA, were tested. Fresh-cut apples were dipped into different solutions and then stored at 4 °C, and physicochemical and biochemical analyses were performed at 0, 4, 8, and 12 days of storage. Results demonstrated that all four combinations improved the shelf-life of fresh-cut apple by slowing down the qualitative postharvest decay, total soluble solid, and titratable acidity. The browning index was highest in the control samples (82%), followed by CMC+SA (53%), CMC+SA+CA (32%), CMC+SA+OA (22%), and finally CMC+SA+CA+OA (7%) after 12 days of cold storage. Furthermore, coating application increased the bioactive compound content and antioxidant enzyme activities. Furthermore, the synergistic activity of SA+CMC+CA+OA reduces enzymatic browning, prolonging the postharvest life of minimally processed 'Annurca Rossa del Sud' apples.

Effects of Annona muricata Extract on Trypsin, Cathepsin B and Collagenase Activities and Textural Changes in Chilled Macrobrachium rosenbergii.

Texture is an important sensory attribute for overall quality and consumer acceptance of prawns. However, texture is affected during cold storage due to the proteolytic activity of endogenous proteases, resulting in poor quality and a short shelf life. The objective of this study is to determine the inhibitory effects of Annona muricata leaves extract (AMLE) (0, 3, 10 and 20%) on the trypsin, cathepsin B and collagenase activities extracted from the cephalothorax of Macrobrachium rosenbergii. In addition, the textural changes in M. rosenbergii during 20 days of cold storage (4 °C) were also determined. M. rosenbergii were soaked in four different treatments: 0, 3, 10 and 20% AMLE and 1.25% sodium metabisulphate for 10 min at 4 °C. Protease activity was significantly (p < 0.05) reduced at 10 and 20% AMLE. Similarly, cathepsin B showed a significant (p < 0.05) low after treatment at 20% AMLE. The maximum inhibitory activity of trypsin was achieved at 20% AMLE and the standard inhibitor (Tosyl-L-lysyl-chloromethane hydrochloride (TLCK)) compared to the control. Whereas, the lowest collagenase activity was obtained at 20% AMLE compared to the control. These inhibitory effects further maintain the firmness of M. rosenbergii coated with 20% AMLE up to the eighth day of storage when compared to the control. Meanwhile, the highest penetration work was found in the M. rosenbergii coated with 20% AMLE at the twentieth day of storage. In conclusion, treatment at 20% AMLE could be used as a natural preservative to inhibit protease, trypsin and collagenase activity of M. rosenbergii and thus can maintain firmness for up to 8 days of storage.

Effect of modified CEP-3 diluents with aqueous soybean extract on liquid semen quality in Ongole crossbred bull.

Egg yolk (EY) is commonly used as an extracellular cryoprotectant in semen diluents but has some negative effects. Therefore, this study aimed to assess the potential of lecithin derived from plants, such as soybeans, as an alternative extracellular cryoprotectant and to characterize liquid semen quality of Ongole crossbred bulls using a modified caudal epididymis plasma-3 [CEP-3 (m)] as a base diluent and aqueous soybean extract (ASE). A bull with progressive motility (PM) of fresh semen >70% was used. Two soybean extracts were also used, namely, ASE 1 and ASE 2, obtained by extraction procedures 1 and 2, respectively. The study was conducted using an experimental design with 11 treatments and ten replications, with diluents comprising different levels of ASE 1 and ASE 2, as well as a positive control with 10% EY. The parameters measured were motility (M) and its kinetic parameters, including PM, M, velocity curve linear, velocity straight linear, velocity average pathway, linearity, straightness, wobble, amplitude lateral head beat cross frequency, and hyperactivity using computer-assisted sperm analysis, viability, and spermatozoa abnormalities. The CEP-3(m) diluent formula and ASE 1 at a 30% level maintained the PM of spermatozoa up to day 5 (40.7% ± 16.1%) of cold storage. Meanwhile, the CEP-3(m) diluent formula and ASE 2 could only maintain PM >40% until day 3 (42.1% ± 13.5%) of cold storage at a 30% level. The CEP-3(m) diluent and ASE 1 at a level of 25%-30% supported spermatozoa life (viability) up to day 5 with a value >80% (81.8 ± 3.5; 86.4 ± 2.6). The abnormality value of spermatozoa in various diluents during cold storage on days 0-5 was below 20%. Soybean extracts 1 and 2 can substitute EYs as extracellular cryoprotectants in modified CEP-3 basic diluents. Soybean extract 1 can support the life of spermatozoa up to day 5 but may cause the viscosity and movement of spermatozoa to be hyperactive. Soybean extract 2 can support the life of spermatozoa up to the 3rd day of cold storage and produces progressive (non-rotating) movement patterns. Further, research is recommended with higher levels of ASE 2.

Facile green preparation of Cr2O3 nanoparticles combined with probiotics in hydro-beads to produce integrated yoghurt

The current study deals with the green synthesis of chromium oxide nanoparticles (Cr2O3-NPs) by using fig leaf extract as a capping and reducing agent for chromium. X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), and Dynamic Light Scattering (DLS) were employed to characterize the fabricated Cr2O3 nanoparticles. The purity and crystallinity of Cr2O3-NPs were determined using the X-ray diffraction technique. The viability of probiotics in presence of synthesized Cr2O3-NPs concentrations of (0.1, 0.2, 0.3, and 0.4 mg/100 mL) was evaluated and the data showed probiotics have the ability to tolerate and grow at low concentrations. The microencapsulated hydrogel was achieved using sodium alginate and Arabic gum then loaded with probiotics (Lactiplantibacillus plantarum, Ligilactobacillus salivarius) and 0.0, 0.1 and 0.2 mg of Cr2O3-NPs/100 mL. The addition of Cr2O3-NPs did not affect the encapsulation yield and the hydro-beads were non-spherical, irregular, and unequal in shape with a rough appearance. All hydro-beads after exposure to gastrointestinal conditions have the recommended level for probiotics to have a healthy impact. Also, the produced hydro-beads were added to produce integrated yogurt. The yogurt samples were evaluated chemically, microbiologically, and sensory during 21 days of cold storage. The probiotics in yogurt persisted stable in the same log cycles with slight improvement during the last two weeks. All yogurt treatments' protein, acidity, dry matter, and fat levels increased during storage. Yogurts with hydro-beads containing Cr2O3-NPs showed a lower pH than controls. The overall acceptability of all yogurt treatments was unaffected by green synthesized Cr2O3-NPs levels.

Effect of apple peel extracts on storage quality of quince juice

Enzymatic browning is one of the reactions influencing the quality of some fruit juices such as quince juice. Nowadays, there is an increased demand for application of antibrowning agents. This research was aimed at the effects of using each ethanolic and aqueous apple peel extracts (EAPE, AAPE) in two concentrations (0.3 and 3%) as inhibitor agents for polyphenol oxidase activity (PPO) of quince juice and their effects on the browning index (BI), total soluble solids (TSS), pH, total titratable acidity (TA), and total phenolic content (TPC) during storage at 4°C for 15 d. The effectiveness of 3% (w/v) alcoholic apple peel extract efficiently inactivated the activities of PPO compared with another three extracts during whole refrigerated storage time. The lowest inhibition percentage value of BI was found in 0.3% AAPE supplemented quince juices. EAPE and AAPE with concentrations of 3% had significantly larger pH values than that of EAPE and AAPE with concentration 0.3% and untreated quince juices at a final day of cold storage. TA values of juice samples untreated and treated with apple extracts did not show significant changes that ranged between 74-75 mg/100 ml at the beginning of storage and decreased with increased storage time, ranging between 0.68-0.72 mg/100 ml at the end of storage. The addition of apple peel extracts during the storage of quince juice had a positive effect on TSS values of the samples. Significantly larger TPC values (P&lt;0.05) were obtained with 3% EAPE incorporated juice samples in comparison with other treatments.

Minimum O2 levels during storage to inhibit aerobic respiration and prolong the postharvest life of 'Tommy Atkins' mangoes produced in different growing seasons

The definition of the minimum O2 levels required to maximally inhibit fruit aerobic respiration is essential to efficiently delay ripening and senescence during long-distance transportation. The aim of this study was to determine the minimum O2 levels required to maximally inhibit the aerobic respiration and prolong the postharvest life of 'Tommy Atkins' mangoes produced during the summer, winter and spring growing seasons in the São Francisco Valley (SFV), Brazil. For the identification of the minimum O2 levels, mangoes were stored for 42 days at 9 °C and 90–95% RH. The change from aerobic to anaerobic metabolism was weekly determined based on the levels of O2, CO2 and ethanol production inside hermetically closed containers containing fruit samples. The minimum O2 levels required to maintain aerobic respiration of mangoes produced in the summer, winter and spring changed from 0.25 to 13.75 kPa, 0.80 to 2.30 kPa and 1.42 to 17.40 kPa, respectively, as the storage duration increased. In order to validate the minimum O2 levels to maintain fruit aerobic respiration and quality, ‘Tommy Atkins’ mangoes produced in the SFV were harvested at the commercial maturity in the winter growing season in 2022 and were stored under dynamic controlled atmosphere (DCA) conditions with the minimum O2 levels determined with fruit produced in the same growing season in the previous year, 2021. Fruit stored under DCA were compared to fruit stored in refrigerated atmosphere (RA) for 60 days at 9 °C and 90–95% RH. The minimum O2 levels used in the DCA effectively inhibited fruit ripening, controlled black flesh and reduced rot incidence during 60 days of cold storage and 60 + 7 days of shelf life.

Formulation of Fruit-Based Probiotic Drink From Snake Fruit (Salacca Zalacca) and Lactiplantibacillus plantarum subsp. plantarum Dad-13

Snake fruit contains monosaccharides, mainly fructose and glucose, which are indispensable substrates for the growth factors of probiotic bacteria. Therefore, this study aims to develop the Fermented Snake Fruit Juice (FSFJ) using the local probiotic bacteria Lactiplantibacillus plantarum subsp. plantarum Dad-13. The results showed that the optimal fermentation time was 24 hours, with a viable cell count of 2.7×108, pH 3.77, and total acid of 0.33%. The glucose and fructose content in FSFJ were decreased during fermentation. The addition of sucrose at 0%, 3%, and 6% showed that different sucrose concentrations were statistically insignificant to the viable cell count, pH, and total acid. A hedonic test was conducted, where the sample with a 6% sucrose level was the most preferred by the panelists hence, deemed as the best formulation. Furthermore, the optimal formulation sample was stored at 4°C for 30 days, and the result indicated that the viable cell count did not present a significant difference. The pH value was decreased from 3.68 to 3.60 and the total acid was increased from 0.42% to 0.56%. The volatile compounds of FSFJ were dominated by compounds responsible for snake fruit character, such as methyl 4-methyl-2-pentanoate and methyl β-methyl valerate, with some fermentation-related volatile compounds. In conclusion, Snake Fruit Juice (SFJ) is a suitable carrier medium for probiotic bacteria and remains of sufficient quality after 30 days of cold storage.

Active Poly (Lactic Acid) Films with Rice Straw Aqueous Extracts for Meat Preservation Purposes

Aqueous extracts from rice straw (RS), using ultrasound-assisted reflux heating extraction (USHT) and subcritical water extraction (SWE), under two process conditions (160 °C, 7 bars; and 180 °C, 11 bars), were obtained and characterised as to their phenolic content and antioxidant and antimicrobial capacities. These extracts were incorporated (6% wt.) into poly (lactic acid) (PLA) films by melt blending and compression moulding that were characterised as to their structural and functional properties and their capacity to preserve fresh pork meat, as vacuum thermo-sealed bags, throughout 16 days of cold storage. The extracts slightly reduced the extensibility, resistance to break, and water barrier capacity of the PLA films but enhanced their oxygen barrier capacity and the UV light-blocking effect. The films with RS extracts were effective at preserving meat quality parameters, inhibiting microbial growth, meat oxidation, discolouration, and weight loss. The SWE extract obtained at 180 °C was the most effective at obtaining active films for meat preservation, exhibiting the greatest antioxidant and antibacterial activity. Therefore, the green SWE technique is useful for obtaining active extracts from RS, allowing for its valorisation in the development of biodegradable active materials useful to preserve food quality.