Days Of Cold Storage Research Articles

Effectiveness of cardamom (Elettaria cardamomum) or bay leaf (Laurus nobilis L.) powder in improving the quality of Labneh.

Herbs and spices are natural ingredients that have been widely used not just as food flavouring but also for their health attributes. The antioxidant, antimicrobial and anticancer components present in them enhance the health and medical status of human beings. The present study aims to produce Labneh fortified with cardamom and bay leaf powder to enhance the quality and shelf life. Cardamom or bay leaf powder were added separately at the ratios of 0.25, 0.50, 0.75 and 1% (w/w) to Labneh and the treatments were compared with a control without cardamom or bay leaf powder during storage (at 5 ±1°C for 40 days). The total solids, fat, ash, carbohydrate and fiber contents were insignificantly higher in Labneh containing cardamom or bay leaf powder than control. The titratable acidity of Labneh gradually increased, whereas the pH values decreased by increasing the concentration of cardamom or bay leaf powder during the storage period. No significant differences were found in any textural parameters between Labneh containing condiments and control, except for that containing 1% cardamom or bay leaf powder, which exhibited higher hardness during the storage period. Minerals, antioxidants activity (RSA%), total phenolic (TPC) and total flavonoids content (TFC) increased with the increase of the added percentage of cardamom or bay leaf powder compared to control. Due to the stimulatory effect of cardamom and bay leaves on Lactic acid bacteria (LAB), the viability of the total bacterial count (TBC) gradually increased as the level of those condiments increased. The control became moldy after 10 days of cold storage while Labneh containing condiments remained unspoiled with yeasts and moulds for up to 30 days of cold storage. Sensory evaluation indicated that 1% addition of cardamom and 0.75% of bay leaf powder to Labneh improved quality and extends the shelf life of Labneh up to 30 days at 5 ±1°C. Labneh supplemented with cardamom or bay leaf powder can be considered as a novel product with acceptable quality and extended shelf life.

Postharvest Conservation of ‘BRS Nubia’ Hybrid Table Grape Subjected to Field Ultra-Fast SO2-Generating Pads before Packaging

The gray mold caused by Botrytis cinerea is the main concern for the postharvest conservation of table grapes worldwide, and the use of sulfur dioxide (SO2) is the most common practice for its control. The aim of this work was to assess the postharvest conservation of the hybrid table grape ‘BRS Nubia’ by using a new technology known as a field ultra-fast SO2-generating pad before packaging the grapes. The fruits were harvested in the 2021 season from a commercial vineyard located at Marialva, Parana, Brazil. The experiment was conducted in a completely randomized design, with 4 treatments and 4 replications, and each plot consisted of 10 bunches. The treatments included: (a) control; (b) field ultra-fast SO2-generating pad (FUFR) during the 4 h before packaging; (c) dual-release SO2-generating pad (DR) during cold storage; and (d) FUFR pad during the 4 h before packaging in combination with the DR pad during cold storage. The bunches were packaged in 0.5 kg plastic clamshells and placed in carton boxes with a capacity of 10 units each. The treatments were evaluated after 30 and 45 days in cold storage (1 ± 1 °C) by means of the incidence of gray mold, shattered berries, stem browning, bunch mass loss and bleaching. After 45 days, the boxes were removed from cold storage and kept without the pads and liners for 3 days at room temperature (22 ± 1 °C), and the incidence of gray mold, shattered berries and stem browning were assessed. The use of the FUFR pad before packaging and the DR pad during cold storage, combined or not, were efficient at controlling gray mold, keeping the incidence of the disease very low. Both pads were also efficient at preventing the mass loss of grapes, but the percentage of shattered berries was lower when the FUFR pad was used. This allowed grapes to arrive already sanitized to the packing house, and no additional SO2-generating pads were needed, representing savings in economic terms for packaging operations. The stem browning, the chemical properties, and the color attributes of berries were not influenced by any treatment.

Duration of of Low-Temperature Storage, Clove Topping and Gibberellic Acid on Emergence, Yield and Yield Components of Garlic.

Dormancy of freshly harvested garlic cloves does not allow early emergence, and preplanting garlic clove treatment is critical for more than one cycle of production in a year. This field experiment was conducted to assess the effect of treating cloves on emergence, growth, and yield of “Tseday” variety during the main cropping season of 2014/2015 and off-season of 2015/16 at Haramaya University. The experiment was arranged in a factorial combination of four (cold stored at 7°C for the duration of 10, 20, and 30 days and stored at room temperature 21°C for 30 days as control), two (whole and topped clove), and four GA3 treatment at concentration of 0, 125, 250, and 375 mg/l and distilled water treatment as second control laid out in randomized complete block design with three replications. The three main factors (clove type, cold storage duration, and GA3) and growing season showed significant influence on phenology, growth, bulb yield and yield components, and all size categories of cloves, while GA3 showed nonsignificant effect on days to emergence of cloves. Clove type interacted with cold storage duration and GA3, and cold storage duration interacted with GA3 significantly to influence all characters of the variety. In addition, the growing season also interacted with clove type and GA3 to influence all categories of clove size, bulb diameter, average bulb weight, and total bulb yield. The three main factors (clove type × cold storage duration × GA3) interaction significantly influenced all characteristics of the variety. However, 30 days of cold-stored and topped cloves reduced dormancy period and days to maturity by 18.84 and 19.50 days, respectively, and increased total bulb yield by 70.32% as compared to the control treatment. In addition, this treatment combination significantly increased most of the growth and bulb yield components, while the number and weight of small-sized cloves were decreased. Hence, it can be concluded that 30 days of cold storage and topping of cloves without soaking under GA3 could be recommended to enhance early emergence, good vegetative growth, and total bulb yield of the garlic variety both under rain-fed and irrigated conditions.

Response of Qualitative Traits and Antioxidant Systems to Chitosan Postharvest Treatment in 'Black Golden' Japanese Plum.

In this study, the influence of a chitosan-based coating was assessed on qualitative traits and non-enzymatic and enzymatic antioxidant systems in Prunus salicina, ‘Black Golden’ Japanese Plum, during 35 days of cold storage followed by 3 days at 24 °C to evaluate its shelf life. Chitosan coating delayed the physico-chemical traits such as the total soluble solids, titratable acidity, firmness and skin color associated with the plum ripening process during cold storage and shelf life. Furthermore, the highest bioactive compounds’ content and antioxidant activity in the coated plum were registered during the stored period. Chitosan-based coating enhanced the activities of superoxide dismutase and ascorbate peroxidase during cold storage and shelf-life. Moreover, this edible coating contributes to reducing membrane damages with lower lipoxygenase activity and, consequently, malondialdehyde accumulation. A multivariate statistical analysis approach identified the two key components, correlated to all analyzed traits, that influenced the changes within chitosan coated and uncoated Japanese plums during storage. Chitosan coating is a cheap and eco-friendly tool to delay ripening process and to improve the antioxidant systems and storability of the ‘Black Golden’ Japanese plum.

Supplementation of melatonin to cooling and freezing extenders improves canine spermatozoa quality measures

BackgroundSperm freezing and cold storage are the two most common assisted reproductive technologies in the canine breeding industry. The freeze-thawing process causes significant detrimental changes in both sperm cell structure and function. Previous research has confirmed that excessive accumulation of un-scavenged free radicals (oxidative stress) plays an important role in the cryopreservation-induced damage to sperm cells. Also, the gradual accumulation of the free radicals during cold storage leads to a decline in the sperm quality markers. Melatonin is an endogenous neurohormone synthesized from tryptophan amino acid by pineal glands. Besides its several well-known physiologic roles, melatonin has a significant antioxidant potential through direct free radical scavenging properties. Therefore, the current study was designed to evaluate the potential in vitro protective properties of melatonin (0.5, 1, and 2 mM) on canine sperm cells after freezing or during long-term cold storage (9 days, 5 °C) on most important sperm in vitro fertility markers.ResultsMelatonin at 0.5, 1- or 2-mM concentrations could preserve significantly higher sperm total motility after 4 days of cold storage. However, only the 1- and 2 mM melatonin concentrations could result in better TM and PM values after 7 days of cold storage. Furthermore, melatonin supplementation could preserve higher sperm viability and acrosome integrity after 7 days of storage. Also, it could have significant protective effects on the cooled sperm DNA integrity. In the freezing section of the current research, melatonin at either 1- or 2-mM concentrations could not improve the sperm post-thaw TM and PM, whereas they improved sperm DNA integrity. Also, the post-thaw plasma membrane functional integrity and sperm velocity parameters were not affected by the treatment. Although DMSO (Dimethyl Sulfoxide) as the melatonin solvent could reduce the level of sperm lipid peroxidation and even improve the post-thaw sperm DNA integrity compared to the negative control, it reduced the post-thaw sperm progressive motility. However, the negative effects were reversed by concurrent melatonin supplementation at 1- and 2-mM concentrations.ConclusionThe addition of 1- or 2-mM melatonin to the canine sperm freezing and cooling media could improve sperm motility, viability, acrosome, and DNA integrity.

Suppression of internal browning and maintenance of antioxidants in beeswax plus salicylic acid coated pear fruit during different storage conditions

SummaryPostharvest application of edible waxes blended with antioxidants is an effective strategy to regulate postharvest quality and antioxidant losses in fruits. Effect of beeswax coatings (BW 1.0% and 2.0%) alone or enriched with salicylic acid (SA) on antioxidant properties of pear fruit was studied during 67 days of cold storage and 20 days of supermarket storage conditions respectively. Results showed that under both the storage conditions fruits coated with BW + SA maintained higher total phenolic content (TPC), antioxidant activity and ascorbic acid content (AsA) as compared to the control. Furthermore, combined coatings significantly reduced polyphenol oxidase (PPO) activities and inhibited internal browning (IB) in pears throughout cold and supermarket storage. Overall, the BW 2.0% + SA 2.0 mM exhibited the most competitive effect in terms of preserving the antioxidant properties and preventing internal browning in pears during storage.

Origanum majorana L. Essential Oil-Coated Paper Acts as an Antimicrobial and Antioxidant Agent against Meat Spoilage.

This study first-ever tested the impact of active packaging paper coated with cationic starch containing Origanum majorana L. essential oil with 69.26% carvacrol polyphenol on the physical, chemical, and microbiological quality of minced beef stored at +4 °C for 0, 6, and 12 days. An analysis of electron scanning microscopy and infrared spectroscopy showed origanum oil entrapment on paper. Meat samples packaged without origanum oil at 6th and 12th days of storage were unfit for consumption. In contrary, origanum oil significantly reduced microbial counts by 2.5 log 10 CFU/g, the peroxide value by 22%, lipid oxidation by 22, the pH-dependent meat spoilage value by 27%, dry matter losses by 7%, and antioxidant activity losses by 40% and restored color and odor reductions. Origanum oil extended the shelf-life of minced beef up to the 6th day of cold storage with no negative effect on meat color and odor.

Comparison of Meat Quality Characteristics and Proteolysis Trends associated with Muscle Fiber Type Distribution between Duck Pectoralis Major and Iliotibialis Muscles.

This study was conducted to evaluate the proteolysis trends and change in meat quality during 10 days of cold storage in duck M. pectoralis major (PM) and M. iliotibialis (IL). Duck IL had a higher pH and greater degree of lightness but lower cooking loss than PM (p<0.05). During the 10-day cold storage, the pH value of PM declined significantly (p<0.05), while the meat quality traits of IL were not affected by cold storage (p>0.05). In PM, the redness increased from day 1 to day 5, while cooking loss was lower on day 10 compared to day 5 (p<0.05). There were no significant differences in the activities of cathepsin B and proteasome 20S during cold storage (p>0.05). The activity of calpains declined gradually during 10 days of storage (p<0.05), and the activity of calpains in PM was higher than that in IL (p<0.05). A total of 5,155 peptides were detected and derived from 34 proteins of duck PM muscle, whereas 4,222 peptides derived from 32 proteins were detected from duck IL muscle. Duck PM muscle was composed only of fast type of muscle fiber, whereas IL muscle was composed of both slow and fast types. The proteins responsible for glycolysis or myofibrillar proteins were closely related to changes in meat color or water-holding capacity during cold storage. These results suggest that changes in meat quality characteristics during cold storage are closely related to protein degradation, which is also related to the distribution of muscle fiber types.

Preharvest Applications of Chitosan, Salicylic Acid, and Calcium Chloride Have a Synergistic Effect on Quality and Storability of Date Palm Fruit (Phoenix dactylifera L.)

The ‘Khenizi’ date palm is one of the most recognized date palm cultivars. It is commonly consumed at the Bisr, Rutab, and Tamr stages of ripening; however, the fruit has a short shelf/storage life at this stage of maturity even with refrigeration. Preharvest application of a natural elicitor chitosan (Ch) has been reported to have positive influences on quality and shelf life of many fruits; however, synergetic effects of Chand other natural elicitors have not been investigated. Therefore, this study aimed to investigate the synergistic effect of preharvest spray treatments with Ch 1% in combination with calcium chloride (Ca) 3% and salicylic acid (SA) 2 mm on ‘Khenizi’ date fruit quality and storage life. Fruit quality parameters, including physical and physiochemical characteristics, phytochemical content, and bioactive properties, were determined at harvest time and during cold storage at 2 °C for 60 days for 2 months. Our results revealed that a combination of these elicitors had significantly influenced the fruit quality during storage compared with control. For instance, Ch+SA and Ch+Ca+SA treatments improved total phenolic content (TPC), and the antioxidant activity at harvest and at specific times during the postharvest storage period. Furthermore, Ch+SA+Ca treatment significantly delayed senescence in treated fruits during cold storage for 45 days as compared with other treatments and the control. In addition, Ch+Ca-treated fruits had the lowest weight loss after 45 days of cold storage. Ch+SA treatment had the lowest microbial counts as compared with other treatments, including the control. The significance of this study is that it provides evidence that a combination of these elicitors has the potential to improve fruit quality at harvest, as well as during postharvest storage Future studies should be directed to fine tune the concentrations and combinations that may have commercial applications.

In vitro viability of L. Casei B-442 and fructooligosaccharides integrity in Amazonian sapota-do-solimões functional juice

Sapota-do-solimões (Quararibea cordata) juice was fermented by Lacticaseibacillus casei B-442 to produce a probiotic and a synbiotic juice. The synbiotic juice was obtained by adding fructooligosaccharides (FOS, 7%, w/v). After the fermentation (37 °C by 15 h) the L. casei viability was above 11 log CFU/mL in both juices. The microbial survival rate after 30 days of cold storage (4 °C) was higher in probiotic juice (97%) than in prebiotic juice (82%). The effect of fermentation and the food matrix on L. casei viability was assessed by the simulated digestion at the beginning and the end of cold storage (4 °C for 30 days). After the simulated digestion, the probiotic counts were above 8 log CFU/mL in synbiotic juice and above 4 log CFU/mL in probiotic juice. The main L. casei metabolites produced in the sapota-dos-solimões juice were lactic acid and acetic acid. Isobutyric, and propionic acids presented higher production in synbiotic juice compared to the probiotic juice. No FOS hydrolysis was observed during the storage or the simulated digestion. L. casei did not consume FOS as carbon source. Thus, sapota-do-solimões juice is an exotic suitable non-dairy-based matrix for functional beverages.

Effects of Peeling, Film Packaging, and Cold Storage on the Quality of Minimally Processed Prickly Pears (Opuntia ficus-indica L. Mill.)

Opuntia species exhibit beneficial properties when used to treat chronic diseases, particularly obesity, diabetes, cardiovascular disease, and cancer; however, the presence of spines and glochids in the species’ skin that easily stick into consumers’ fingers has limited their consumption. For this study, white and orange Opuntia ficus-indica fruits from the Canary Islands (Spain) were minimally processed, packed in a passive atmosphere, and stored at 7 °C. The effects of peeling (by hand or with an electric peeler) and two micro-perforated films (90PPlus and 180PPlus) were evaluated. Changes in the quality parameters, gas composition, bioactive compounds, sensory features, and microbial safety of fresh-cut prickly pears were examined during 10 days of cold storage. Both varieties, hand-peeled and electrically peeled, were microbiologically safe (aerobic mesophiles &lt; 7 log(CFU/g fresh weight)) and retained suitable nutritional quality after 8 days of storage. The yield was greater when fruits were electrically peeled than hand-peeled (70.7% vs. 44.0% and 66.5% vs. 40.8% for white and orange fruits, respectively). The concentrations of oxygen and carbon dioxide were above 15% and below 7.5%, respectively, in all the treatments over the shelf life. TSS decreased during storage independently of variety, peeling method, or film. Fructose was the most abundant sugar, followed by glucose and sucrose. The electric peeling machine improved not only the edible part of the fruit but also the contents of bioactive compounds, such as ascorbic acid and phenolic compounds.

Postharvest Spoilage Incidence and Prestorage Treatment in Chinese Chestnut and Complex Hybrid Cultivars

U.S. chestnut (Castanea sp.) production is expanding as knowledge of seedling cultivation and germplasm advances. Chestnuts have high starch and water content, making them highly perishable; therefore, they require cold storage immediately following harvest. Postharvest spoilage remains a significant area for improvement. Several postharvest fungi (including Fusarium sp. and Penicillium sp.) can infect chestnuts during storage, leading to spoilage and nonsellable nuts. The annual crop losses can reach up to 10%, thereby affecting trees differently. Our research objectives were to 1) evaluate spoilage incidence on the interior (i.e., pellicle, kernel) and exterior (i.e., nutshell) of the nut over the course of 200 days of cold storage on eight cultivars and 2) assess the impact of food contact-approved chlorine solution and 2% peracetic acid (PAA) with 27% hydrogen peroxide prestorage treatments for spoilage suppression on ‘Qing’ nuts. Fourteen timepoints were observed during the study period, each with four replications of 16 nuts. An additional four replicates of 16 ‘Qing’ nuts were treated prestorage and observed over seven time points. The incidence of spoilage was reported as the percentage of nonsellable nuts for each treatment and cultivar at four timepoints. The nut interior showed the highest spoilage incidence after 200 days, with four cultivars having &gt;30% nonsellable nuts. Overall, the cultivars had an average of 10% nonsellable nuts from interior spoilage after 60 days in storage. ‘Hong Kong’ had the highest percentage of nonsellable nuts by the end of the study at 60%, whereas ‘Qing’ and ‘Mossbarger’ had the lowest rates, with only 14% nonsellable nuts. Spoilage of the exterior, although less frequent, is visible to buyers and impacts nut marketability. ‘Kohr’ had the highest percentage of nonsellable nuts because of exterior spoilage (35.9%). ‘Mossbarger’ had the lowest percentage of nonsellable nuts because of exterior spoilage (3.1%). ‘Qing’ nuts treated with 500 ppm chlorine and 100/200 ppm PAA demonstrated reduced exterior spoilage with longer storage times. Prestorage treatment did not show efficacy for reducing interior spoilage. This study provides a preliminary report of evidence that cultivar differences influence the spoilage incidence and supports taking nuts to market within 60 days of harvesting. These preliminary data also inform breeding parent combinations and studies of inheritance for postharvest spoilage tolerance at the University of Missouri Center for Agroforestry breeding program.

DEVELOPMENT AND APPLICATION OF ANTIOXIDANT COATING ON Fragaria spp. STORED UNDER ISOTHERMAL CONDITIONS

Strawberry (Fragaria spp.) is a non-climacteric fruit, widely consumed in several countries, but is extremely sensitive and susceptible to mechanical damage during harvest, transport, and storage, reducing the shelf life. In order to prolong the shelf life of this product, edible starch-based coatings were developed, with propolis extract (MSP) and without the addition of ethanolic propolis extract (MS) and uncoated samples, used as control (MC). All samples were stored under isothermal conditions (4 °C ± 0.5 °C), for 10 days. Physicochemical analyzes (pH, mass variation, vitamin C, color, and phenolic compounds) were carried out to characterize and identify the coating efficiency in the conservation of strawberries. The formulations of the coatings with and without the addition of propolis had a significant (p ≤ 0.05) effect on the variation of fruit weight. The propolis coating showed greater stability in the vitamin C content and pH levels, up to the 10th day of cold storage, in comparison to the samples with starch coating and the control. The treatments (MS, MSP, and MC) did not significantly influence (p &gt; 0.05) the color and the content of total polyphenols.

Physicochemical, Organoleptic Evaluation and Shelf Life Extension of Quinoa Flour-Coated Chicken Nuggets

The objective of the current study was to develop innovative quinoa-coated chicken nuggets by using quinoa flour instead of wheat flour and evaluate the impact of this substitution on the shelf life of the product and its nutritional and sensorial stability. The evaluation of the product has been done through physiochemical and microbiological analysis every three days of the storage period compared with negative control (NC) and positive control (BHT) through 24 days of cold storage (4 ± 1°C). During storage, the quinoa flour-coated chicken nuggets showed the best ability for delay of lipid oxidation with a lowest TBARS value of 1.07 mg MDA/kg compared to negative control (NC) (2.39 mg MDA/kg) and positive control (BHT) (2.00 mg MDA/kg). The same trend was observed in protein oxidation, where the quinoa flour was able to retard the protein oxidation better than negative and positive control (BHT) where it showed a carbonyl content of 6.44, 5.39, and 4.20 nmol carbonyl content/mg protein, respectively. The quinoa-coated chicken nuggets showed the lowest microbial load (5.8 × 103 cfu/g) compared to negative and positive controls (1.8 × 105 and 3.8 × 104 cfu/g) at 24 days of cold storage. These findings could be emphasized such that the utilization of quinoa flour in the coating of chicken nuggets is more effective in retarding lipid and protein oxidation, furthermore preventing microbial contamination during cold storage. All these findings might be playing a crucial role in the extending of the shelf life of the product in addition to giving the product a pleasant taste and flavor to consumers.

The beneficial effects of the addition of pulped Agaricus bisporus mushroom body co-product to Kraft pulp packaging materials

The aim of this study is to up-cycle mushroom production waste by incorporating macerated mushroom caps and stalks into moulded Kraft pulp packaging material and to compare the properties of this new material with existing food packaging materials, namely moulded pulp packaging (MPP) and polypropylene (PP) punnets. Corrugated cardboard fibre (CCF) was blended with 30% waste mushroom caps and stalks (MW) with and without addition of alkyl ketene dimer (AKD). Microbiological assessment of the packaging material from selected production stages and the finished punnets was conducted the determine levels of aerobic colony count, Pseudomonas spp., and yeasts and moulds. Also, finished punnets were characterized for their physical properties (moisture, density, surface hydrophobicity, mechanical properties, microstructure) and used for cold storage trials using fresh mushrooms comparing performance to MPP and PP punnets in terms of change in colour (CIE L*, a*, b*) and microbial load of the packed mushrooms. During seven days of cold storage of fresh mushrooms, both mushrooms and packaging materials were analysed for their total aerobic bacteria, Pseudomonas spp., and yeasts and moulds. Results showed that at the end of the storage, MW/CCF and MW/CCF + AKD punnets showed similar performance with PP punnet on the microbial quality of fresh mushroom. The fresh mushrooms had better colour compared with those stored in MPP. The paper-based punnets had higher microbial growth in the packaging material than PP punnet. Incorporation MW improved the mechanical properties of CCF. The MW/CCF and MW/CCF + AKD punnets had a higher Young’s modulus than MPP. Results indicated that, moulded pulp punnets prepared using 30% mushroom waste used for fresh mushroom packaging provide the similar microbial quality with better product colour compared with commercial counterparts while allowing agri-waste up-cycling.

Biochemical Composition and Antioxidant Activity of Different Types of Tomatoes Affected by Ethylene Treatment

The effect of ethylene on biochemical composition and antioxidant activity in beefsteak, heirloom and cluster type of tomatoes were determined. For that purpose, tomato fruit were harvested at breaker maturity stage and divided into two groups one of which was applied with 150 μL L−1 ethylene while another remained untreated. Ethylene treated and untreated control fruit were stored at 12 °C and 90+5% relative humidity for 35 days with subsamples removed every 7 days for quality analysis. After each removal time, fruit were kept at 20 °C for additional 3 days to determine shelf life performance. Ethylene treatment enhanced the breakdown of total chlorophyll and accumulation of lycopene and carotenoid contents. At the end of cold storage and shelf life period, the maximum antioxidant activity, carotenoid and flavonoid contents were recorded in ethylene treated heirloom type tomatoes. It can be concluded that ethylene treated heirloom type tomatoes exhibited maximal postharvest quality as compared to beefsteak and cluster type of tomato in term of biochemical composition and antioxidant activity after 35 days of cold storage and shelf life.

Effects of green tea polyphenols and α-tocopherol on the quality of chilled cat spermatozoa and sperm IZUMO1 protein expression during long-term preservation

Sperm IZUMO1 protein was recently found to be a crucial mediator in the interaction and fusion with eggs, indicating an important role in assuring the favourable outcome from long-term preservation of chilled semen. The purpose of this study was to investigate whether supplementation of chilled semen extender with green tea polyphenols together with α-tocopherol would provide synergistic effects to prolong sperm survival and maintain IZUMO1 protein stability in cat spermatozoa. Sperm samples were collected from the cat epididymis before being diluted with semen extender containing various concentrations of α-tocopherol (0, 2.5, 5 and 7.5 µg/ml) and 0.75 mg/ml green tea polyphenols and cooled to 4 °C. One sample without antioxidants served as a control. Sperm characteristics and IZUMO1 protein expression were investigated before and after chilling at 3, 6, 9, 12 and 15 days. Using α-tocopherol at 5 µg/ml together with 0.75 mg/ml green tea polyphenols in the semen extender is the most suitable condition to retain the sperm characteristics up to nine days of preservation. Cat IZUMO1 proteins, 17 kDa, were identified at the equatorial segment of acrosome reacted sperm. Without antioxidant, cold storage can gradually degrade the IZUMO1 protein level. Sperm IZUMO1 protein was markedly conserved by supplementation of 5 µg/ml α-tocopherol together with 0.75 mg/ml green tea polyphenols up to 12 days in cold storage. These findings indicate that green tea polyphenols and α-tocopherol have protective effects on the preservation of sperm characteristics and IZUMO1 protein integrity of cat epididymal sperm during long-term chilling.

Assessment of bacterial growth in leukoreduced cold-stored whole blood supports overnight hold at room temperature prior to filtration: A pilot study.

Whole blood (WB) transfusion has regained attention to treat trauma patients. We reported no significant changes in in vitro quality through 21 days of cold storage for leukoreduced WB (LCWB) when time to filtration was extended from 8 to 24 h from collection. This study evaluated the impact of extended WB-hold at room temperature (RT) prior to leukoreduction on proliferation of transfusion-relevant bacteria. WB units were spiked with suspensions of Klebsiella pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Listeria monocytogenes prepared in saline solution (SS) or trypticase soy broth (TSB) to a concentration of ~0.2CFU/ml (N= 6). Spiked units were held at RT for 18-24 h before leukoreduction and cold-stored for 21 days. Bacterial growth was determined on days 2, 7, 14 and 21. In vitro quality of WB inoculated with unspiked diluents was assessed. K. pneumoniae and S. pyogenes proliferated in WB prior to leukoreduction reaching concentrations ≤102 CFU/ml. These bacteria, however, did not proliferate during the subsequent cold storage. S. aureus did not survive in WB while L. monocytogenes reached a concentration of ~102 CFU/ml by day 21. LCWB in vitro quality was not affected by SS or TSB. Extended WB-hold prior to leukoreduction allowed proliferation of bacteria able to resist immune clearance, although they did not grow to clinically significant levels. While L. monocytogenes proliferated in LCWB, clinically relevant concentrations were not reached by day 21. These data suggest that transfusing LCWB may not pose a significant bacterial contamination safety risk to transfusion patients.

Proteomic changes in mango fruit peel associated with chilling injury tolerance induced by quarantine hot water treatment

The aim of this study was to identify proteins associated with the chilling injury (CI) tolerance induced by hot water treatment (HWT) in ‘Keitt’ mango fruit. A comparative proteomic analysis was performed between fruit with HWT (46.1 °C, 90 min) and non-treated (Control) after cold storage (0 and 20 d at 5 °C) and ripening (7 d at 21 °C); the expression of genes encoding some selected proteins was analyzed by real-time PCR. Twenty-six proteins were differentially expressed after HWT, 36 after 20 days of cold storage and 33 after ripening. Polypeptides with higher accumulation in HWT fruit included eleven heat shock proteins (HSPs), eight enzymes of the energetic metabolism (ACO1, ACO2, GAPDH-1, GAPDH-2, ADH, SDH, ADK, and ACAA) and seven of the secondary metabolism (PAL, CHS, CHI, PDS, HPPD, IsoCH, and PPO), four antioxidant enzymes (CAT, POD, Prx, and APX,), four proteins involved in hormone metabolism (P-gp2, ARF, ERF, and GA3ox1), two pathogenesis-related proteins (β-Glu and 2 s alb), four enzymes of cell wall metabolism (EGase, β-Gal, Rab11 and αMan), and three proteins involved in chloroplast metabolism (RuBisCo, PDX1, and rpl2). Non-treated fruit showed higher accumulation of polyphenol oxidase and alcohol dehydrogenase, suggesting a higher oxidation of phenols and lower efficiency in energy production. The CI tolerance induced by the quarantine HWT in mango fruit appears to be associated with the prevention of protein denaturation, the maintenance of the membrane functionality and energy efficiency, the activation of antioxidant and defense systems, the preservation of cell wall metabolism, and the synthesis of secondary metabolites.

Pathogenic potential of the surviving Salmonella Enteritidis on strawberries after disinfection treatments based on ultraviolet-C light and peracetic acid

Fresh fruits, especially strawberries, are usually consumed raw without any step to ensure their food safety. Salmonella enterica is one of the most important etiologic agents for foodborne diseases throughout the world and its ability to respond to some stress responses makes it even more dangerous. In the present investigation, we study the survival of S. Enteritidis (CECT-4300) on strawberries after 2-min of various disinfection steps (NaClO (200 ppm), peracetic acid (PAA; 40 ppm), water-assisted UV-C (WUV-C), and the combination WUV-C and 40 ppm of PAA (WUV-C + PAA)) and after 5 days of cold storage (4 °C). Moreover, the pathogenic potential of the surviving bacteria, such as the ability to survive throughout the gastrointestinal tract (GI) and subsequently the capability to adhere to and invade Caco-2 cells, was tested at each sampling point. After 2-min of washing procedures, reductions of S. Enteritidis on strawberries were ≥1.2 log, with no significant differences among treatments. However, the use of WUV-C + PAA treatment achieved the highest reductions in washing water, in which S. Enteritidis was not detected (<DL). At the end of 5-day storage period, reductions of the WUV-C + PAA treated-samples were lower in comparison with PAA-treated samples (P < 0.05). The effect of the treatments used did not interfere with the survival of S. Enteritidis along the GI tract. After disinfection and subsequent GI simulation, all remaining populations demonstrated an elevated ability to adhere in Caco-2 cells (67.5–81.1%) compared with those obtained on untreated strawberries (61.4%). Concerning the ability of invasion, no significant differences could be observed. Remarkably, after 5 days at 4 °C, the adherence of S. Entertidis significantly decreased in the samples with the combined treatment meanwhile the invasion ability was not detected for any treatment. The results of the present study are essential for the quantitative microbial risk estimations.