Weeks Of Cold Storage Research Articles

Probiotic Beverage from Mangosteen Juice Fermented with Lactobacillus Strains

In the present work, a non-dairy fermented beverage was produced from mangosteen juice using Lactobacillus strains. Mangosteen juice was fermented with 3 probiotic strains: Lactobacillus casei TISTR 390, L. fermentum TISTR 391 and L. plantarum TISTR 1463 in single and co-cultivations at an incubation temperature of 30°C for 72 h. The changes in chemical and microbiological properties during fermentation at 0, 24, 48 and 72 h were investigated. It was found that the acidity and viable cell count of fermented mangosteen juice increased at 72 h fermentation in all of the treatments, whereas the level of total soluble solid, phenolic compound, and pH decreased. Sensory evaluation showed that mangosteen juice fermented with the combination of L. casei TISTR 390, L. fermentum TISTR 391, and L. plantarum TISTR 1463 had overall the acceptability score in the group of highest score (6.74; moderately like). Furthermore, it showed the highest taste liking score.However, after 4 weeks of cold storage at 4°C, the level of phenolic compound, pH and viable cell count of this fermented juice slightly fell, but the total soluble solid remained the same. Interestingly, the fermented juice had good antioxidant activity compared with the control (without lactic acid bacteria). Moreover, the low concentration of fermented mangosteen juice exhibited to have higher toxicity to colon tumor cell (SW620) than that of the control. This finding suggested that these probiotic mangosteen juice could be served as a healthy alternative functional beverage for general consumers, especially adults and the elderly.
 HIGHLIGHTS
 
 Non-dairy prebiotic beverage was produced from mangosteen juice using Lactobacillus strains
 Mangosteen juice fermented with the combination of 3 probiotics of Lactobacillus strains had the highest overall acceptability and taste liking score
 The antioxidant activity of probiotic mangosteen juice was higher than those of the control mangosteen juice which showed the lower IC50 values
 The low concentration of mangosteen probiotic beverage exhibited to have higher toxicity to colon tumor cell (SW620) than that of the control mangosteen juice 
 
 GRAPHICAL ABSTRACT

Listeria monocytogenes cross-contamination during apple waxing and subsequent survival under different storage conditions

This study evaluated Listeria monocytogenes cross-contamination between inoculated fruits, waxing brush, and uninoculated fruits during apple wax coating and investigated the fate of L. monocytogenes on wax-coated apples introduced via different wax coating schemes. There were 1.8–1.9 log10 CFU/apple reductions of L. monocytogenes on PrimaFresh 360, PrimaFresh 606, or Shield-Brite AP-450 coated apples introduced before wax coating after 6 weeks of ambient storage (22 °C and ambient relative humidity). L. monocytogenes showed a similar trend (P > 0.05) on waxed apples under cold storage (1 °C and ∼ 90% relative humidity); there were 1.8–2.0 log10 CFU/apple reductions of L. monocytogenes during the 12 weeks of cold storage regardless of wax coating type. For cross-contamination study, a waxing brush was used to wax one inoculated apple (6.2 log10 CFU/apple); then, this brush was used to wax five uninoculated apples in a sequence. There were 3.7, 3.5, 3.3, 2.9, and 2.7 log10 CFU/apple and 3.6 log10 CFU/brush of L. monocytogenes transferred from the inoculated apple to uninoculated apple 1 to apple 5, and the waxing brush, respectively. The die-off rate of L. monocytogenes on wax-coated apples contaminated during wax coating was not significantly different from that contaminated on apples before wax coating, and 1.8–1.9 log10 CFU/apple reductions were observed during the 12 weeks of cold storage. The application of wax coatings, regardless of wax coating type, did not impact the survival of endogenous yeasts and molds on apples during ambient or cold storage. L. monocytogenes transferred onto waxing brushes during wax coating remained relatively stable during the 2-week ambient holding. Fungicide application during wax coating reduced (P < 0.05) yeast and mold counts but had a minor impact (P > 0.05) on the survival of L. monocytogenes on apples after 12 weeks of cold storage. Collectively, this study indicated that a high cross-contamination risk of L. monocytogenes during apple waxing, and L. monocytogenes on wax-coated apples introduced via different scenarios is stable during subsequent cold storage, highlighting the need for potential intervention strategies to control L. monocytogenes on wax-coated apples.

Postharvest Potential of Cold-hardy Table Grapes

The University of Minnesota Grape Breeding Program has developed cold-hardy wine grape cultivars that have facilitated the establishment of an economically important grape industry for the Midwest region. In recent years, the program has renewed efforts to breed cold-hardy table grapes. Table grapes might require postharvest storage if they are to be transported or stored for any period of time. Rachis dehydration, berry splitting, and decay can affect the postharvest quality of table grapes. In this study, we evaluated these postharvest traits in six released cultivars and nine advanced selections in the breeding program. For two growing seasons, we used industry standard packaging to assess postharvest traits (rachis dehydration, berry splitting, decay, and overall acceptability) at 2, 4, and 6 weeks of cold storage at 2.2 °C. The growing season had a significant effect on postharvest traits; therefore, the two were examined separately. There were significant differences in postharvest storage times for all traits, except berry splitting in 2020. Mean rachis dehydration reached unacceptable values (&gt;3) after 4 weeks of postharvest storage in 2019 and after 6 weeks in 2020. All other trait means remained acceptable for many cultivars even after 6 weeks of postharvest storage. Advanced selections performed at and above the level of released cultivars, suggesting that selections will perform well in cold-hardy regions. The data collected regarding fruit quality and postharvest storage for two seasons will help to inform and improve breeding of cold-hardy grape cultivars.

Combined effect of beet powder and lentil flour as a partial nitrite substitute on physicochemical, texture and sensory characteristics, color, and oxidative stability of pork bologna.

The combined effect of beet powder (BP; 0.1%, 0.3%, and 0.5%) and 6% lentil flour (LF) as a partial nitrite substitute on quality attributes of pork bologna incorporated with 7.5% mechanically separated pork during 12weeks of cold storage was evaluated. A randomized block experimental design with nine treatments and five storage times (0, 3, 6, 9, and 12weeks) was used for pH, thiobarbituric acid reactive substance, protein oxidation (carbonyl and sulfhydryl), and color parameters. Bologna preparation at a pilot plant scale was replicated three times. LF addition resulted (p<0.05) in higher viscosity, emulsion stability, and lower expressible drip. Together BP and LF decreased protein oxidation during storage but were not as effective as nitrite with respect to lipid oxidation. Bologna with BP addition showed lower lightness and higher redness, whereas LF increased lightness and decreased redness. A consumer panel rated color acceptability of bologna lower with LF addition, whereas BP raised color acceptability. However, addition of the highest BP level alone to the bologna was negatively perceived as a result of the low acceptability of purge color of the vacuum-packaged bologna slices. Consequently, the combination of BP and LF could be used to improve eating quality and stability attributes when used as a potential nitrite substitute.

Nano-clay, layered-double hydroxide (LDH), improves the efficacy of double‐stranded RNA in controlling postharvest decay

Major losses in postharvest fruit and vegetables are due to rotting caused by pathogenic fungi. The environmental impact of fungicides requires new eco-friendly strategies to control postharvest pathogens. B. cinerea, a major postharvest pathogen, was controlled by dsRNA targeting three key genes in ergosterol biosynthesis. However, due to the limited stability of dsRNA, we incorporated the dsRNA in layered-double hydroxide (LDH) nano-clays to protect the dsRNA from degradation and serve as a long-term controlled-release mechanism. Our results show that either in-vitro and in-planta, the hyphae and conidia emergence zone of the germination tube of B. cinerea can uptake free dsRNA or when it was complexed with LDH. The fungal inhibition provided by either form of dsRNA was selective to B. cinerea and not for other pathogens. Notably, the LDH-dsRNA complex maintained its potency for at least six weeks of cold storage and reduced gray mold development significantly better when compared to naked dsRNA after long storage. Scanning electron microscopy images implies that LDH by itself forms a mechanical barrier and delays the fungal colonization in the fruit. Furthermore, a modified atmosphere can influence the release of the dsRNA from the LDH complex. Thus, increased levels of CO2 and humidity increase LDH degradation, and the dsRNA release from the complex. Overall, our results suggest that the incorporation of dsRNA in LDH under suitable conditions may serve as a safe alternative to the postharvest application of fungicides.

Hexanal application reduces postharvest losses of mango (Mangifera indica L. variety "Kent") over cold storage whilst maintaining fruit quality

Mango (Mangifera indica L.) is a widespread crop that is affected by many factors that promote deterioration and limit its shelf life. This study aims to evaluate the effect of hexanal treatment and cold storage conditions on mango quality and postharvest losses. Mangoes var "Kent" were harvested from a commercial orchard located in Korhogo in the northern area of Ivory Coast. The fruit was then dipped in an aqueous hexanal formulation and stored at a cold temperature (13 ºC) before ripening at laboratory temperature (30 °C). Their quality was assessed during storage and after ripening. The results showed that hexanal reduced postharvest losses by 22.85% and spoilage by 12% after four weeks of cold storage. Furthermore, the results revealed that hexanal treatment increased fruit firmness and ascorbic acid content compared to control fruit. However, there was no difference in soluble solids content, titratable acidity, pH, dry matter, and colour between treated and control fruit. Sensory analysis showed that hexanal treatment improved some sensory descriptors such as overall likeability, chewiness, sweetness, and colour of the mango flesh. Therefore, our study suggests that postharvest dipping of mangoes in the hexanal solution, combined with cold storage conditions, extends the shelf life of the fruit while maintaining or even improving its organoleptic features.

Effects of Gum Arabic Coatings Enriched with Lemongrass Essential Oil and Pomegranate Peel Extract on Quality Maintenance of Pomegranate Whole Fruit and Arils.

The effects of gum arabic coatings combined with lemongrass oil and/or pomegranate peel extract on freshly harvested mature ‘Wonderful’ pomegranate fruit were studied. Fruit were coated with gum arabic (GA) (1.5% w/v) alone or enriched with lemongrass oil (LM) (0.1% v/v) and/or pomegranate peel extract (PP) (1% w/v). Fruit were packed into standard open top ventilated cartons (dimensions: 0.40 m long, 0.30 m wide and 0.12 m high), and stored for 6 weeks at 5 ± 1 °C (90% RH). Evaluations were made every 2 weeks of cold storage and after 5 d of shelf life (20 °C and 65% RH). Fruit coated with GA + PP (4.09%) and GA + PP + LM (4.21%) coatings recorded the least cumulative weight loss compared to the uncoated control (9.87%). After 6 weeks, uncoated control and GA + PP + LM recorded the highest (24.55 mg CO2Kg−1h−1) and lowest (10.76 mg CO2Kg−1h−1) respiration rate, respectively. Coating treatments reduced the incidence of decay and treatments GA + LM + PP and GA + PP recorded the highest total flavonoid content between 2 and 6 weeks of storage. The findings suggest that GA coatings with/without LM and PP can be a beneficial postharvest treatment for ‘Wonderful’ pomegranates to reduce weight loss and decay development during cold storage.

In Vitro Propagation, Genetic Assessment, and Medium-Term Conservation of the Coastal Endangered Species Tetraclinis articulata (Vahl) Masters (Cupressaceae) from Adult Trees.

Tetraclinis articulata (Vahl) Masters is an endangered tree growing in coastal and arid environments that is widely exploited by the timber and resin industry, among other applications. In this context, the use of in vitro techniques is highly encouraged for its propagation. We present a protocol for micropropagation using twigs from adult trees as a source of explants. The Schenk and Hildebrandt basal medium (SH) supplemented with 30 g L−1 sucrose, 6.5 g L−1 plant agar, 4.0 mg L−1 6-benzyladenine (BA), and 0.05 mg L−1 1-naphthaleneacetic acid (NAA) provided the optimum multiplication rate (90.48 ± 9.52 explants with basal shoots and 2.58 ± 0.29 basal shoots per explant). Application of activated charcoal (AC) or ½ Knop solution in a liquid overlay produced significantly longer shoots. Supplementation of solid media with indole-3-butyric acid (IBA) or NAA gave low rooting percentages (<17%). Addition of 0.9 g L−1 AC improved rooting (40%) but rooting performance was optimal (66.7%) after a pulse treatment consisting of 4 h immersion in liquid SH medium without growth regulators, followed by 8 weeks of cultivation. Rooted microplants were successfully acclimatized (93.33%) in a peat moss and vermiculite mixture (1:1 v/v ratio). The genetic stability of the in vitro regenerated plantlets was confirmed using the randomly amplified polymorphic DNA (RAPD) technique. Explant survival and growth remained higher than 90% after 28 weeks of cold storage at both 4 °C and 10 °C. The protocol presented here allows for largescale T. articulata production and could be applied for both ex situ conservation strategies and industrial purposes.

Degradation of Red Blood Cell Deformability during Cold Storage in Blood Bags

RBC transfusions are a life-saving procedure, aiding both chronic and acute patients in restoring tissue oxygenation. The ability to store collected RBC units for prolonged periods has been one of the most transformative advances in medicine, significantly improving the reliability and the speed of access to blood. However, RBCs undergo a number of metabolic, structural, and biochemical changes during storage, collectively known as the storage lesion, that is detrimental to the quality of the RBC. A major challenge is the ability to evaluate the extent of the storage lesion, and thus the quality of the stored RBC unit directly prior to transfusion.The storage lesion can directly or indirectly reduce the ability of the RBC to deform through the small openings in the microvasculature. Rigid RBCs pose a risk of sequestration in capillaries, impeding blood flow and reducing tissue oxygenation, and are more likely to be cleared out by endothelial macrophages. Studies have shown that there is a loss in RBC deformability during storage and that the rate of RBC deformability loss is donor-dependent. Thus, RBC deformability can be a valuable and reliable biophysical marker of RBC unit quality.Currently, there is a need for a reliable measurement technique that is repeatable and sensitive enough to observe individual differences in RBC deformability in healthy donors, to enable quality control testing of RBC units. We have developed the microfluidic ratchet device, which sorts RBCs based on their deformability, allowing the measurement of both rigid and deformable sup-populations of RBCs within the sample, and generating a unique deformability curve. Here, we use this assay to predict the quality of stored RBC units.We assessed the deformability of 14 healthy donor RBC units through 8 weeks of cold storage at 4°C, which is 2 weeks beyond the Canadian Blood Services approved 6-week standard in Canada. We measured RBC deformability, standard hematological parameters (MCV, MCHC, MCH, and RDW), and hemolysis levels at the time of RBC unit manufacture (week 0), followed by weeks 2, 4, 6, and 8. The microfluidic ratchet device operates by forcing RBCs to deform and travel through rows of tapered constrictions. Constriction size changes from 7.5 to 1.5 µm and is reflective of the microvasculature and vessel opening sizes encountered by RBCs in circulation. RBCs are sorted into 12 distinct outlets based on their deformability. Distribution of RBCs in outlets 1-12 can be quantified and used to calculate the cumulative distribution curve. The cumulative distribution curve provides a distinct deformability signature of each individual RBC sample, which can be defined as rigidity score (RS). RS provides an easy metric to compare the changes in RBC deformability throughout storage (ΔRS) in a single donor as well as across multiple donors.We show that there are both donor- and sex-specific differences in the RBC deformability signatures of stored RBC units. We observed significant inter-donor variability in RBC deformability measured on the day of the RBC unit manufacture, where male donors showed a more stable RBC deformability range (n=8, RS=3.00±0.18) compared to female donors (n=6, RS= 3.29±0.48). The average RS scores were stable between weeks 0-2 (ΔRS 0.07) and showed a reduction in deformability between weeks 1-6 (ΔRS 0.35), with the greatest loss seen between weeks 6-8 (ΔRS 0.42) of cold storage. Interestingly, the response to cold storage is variable, with ΔRS 0.22 to 0.90, suggesting that some donors are more susceptible to storage related changes in RBC deformability than others. Notably, the change in RS over time was donor-specific and did not correlate with RBC deformability at week 0. The majority of RBCs from male donors (ΔRS 0.485, p<0.05), but none of the female donors (ΔRS 0.172) showed changes in deformability during cold storage, suggesting that RBCs from female donors degrade at a slower rate compared to RBCs from male donors.The ability to profile RBC deformability at the individual blood bag level may help identify more stable RBCs for use in chronic and sensitive patients, or RBC units that can be safely stored beyond the 6-week storage window. DisclosuresNo relevant conflicts of interest to declare.

Effects of Cold Treatments on Seedling Emergence and Growth of Lilium davidii var. unicolor Bulblets

For Lilium davidii var. unicolor bulblets produced by scale propagation, the effects of cold treatments on the sprouting and development of bulblets were studied. The results showed that 5 °C was a more suitable temperature than 2 or 10 °C. Bulblets treated at 5 °C for 3 weeks presented the best uniformity of seedling emergence, and the sprouting rate was 100%. Moreover, the largest bulbs were observed in this treatment after a growing season. It was found that long storage at low temperatures is unfavorable for bulb development. The weight and circumference of bulbs from bulblets that were cold-treated for more than 5 weeks were significantly less than those treated for 1 to 4 weeks. During the first 4 weeks of cold storage, the starch content of bulblets decreased significantly, coinciding with an increase in soluble sugars. The starch and soluble sugar contents in bulblets stored at 2 and 5 °C changed faster than those in bulblets stored at 10 °C. However, the effect of temperature on carbohydrates diminished gradually as the storage time increased. Long storage of bulblets at low temperatures is not good for subsequent growth and development. The results of this study provide important information for accelerating the scale propagation of L. davidii var. unicolor and maximizing bulb yield.

Effect of Harvest Time and Fruit Firmness on Red Drupelet Reversion in Blackberry

Red drupelet reversion (RDR) is a postharvest disorder of blackberries (Rubus L. subgenus Rubus Watson) in which fully black drupelets revert to red after harvest. This disorder can negatively impact consumer perception of fresh-market blackberries. The cause of RDR is hypothesized to be related to intracellular damage sustained because of mechanical and environmental stress during and after harvest. Cultivars differ in susceptibility to this disorder; and cultural factors, including nitrogen rate, harvest and shipping practices, and climate during harvest, influence RDR severity. In this 2-year study, seven genotypes (cultivars and advanced selections) developed in the University of Arkansas System Division of Agriculture (UA) blackberry breeding program, with a range of fruit textures, were evaluated to determine whether firmness was correlated with RDR. In addition, fruit was harvested at four different times (7:00 am, 10:00 am, 1:00 pm, and 4:00 pm) to investigate whether harvest time influences RDR. All seven genotypes were harvested at the four times on two harvest dates per year and evaluated for RDR and firmness after 1 week of cold storage (5 °C). Fruit harvested early in the day had less RDR, with 7:00 am harvests having the least RDR in both years. Significant genotypic differences in RDR and fruit firmness were found in each year. Firmness was negatively correlated with RDR in 2018 and 2019. These results indicate that growers may be able to reduce the prevalence of RDR by choosing cultivars with firm fruit texture and harvesting early in the day.

Effect on Phytochemical Content and Microbial Contamination of Actinidia Fruit after Shock Cooling and Storage

Abstract Mini kiwi fruits are tasty and contain valuable nutrients - vitamin, micro end macroelements and polyphenols. The tested cultivars (Sientiabrskaja, Geneva, Issai, Ken’s Red) belong to two species of Actinidia (A. arguta and A. kolomikta), which tolerate well the conditions of a temperate climate with negative temperatures in winter. The effect of postharvest shock cooling on fruit quality was investigated after 6 weeks of storage in CA and then after 5 days of shelf life. Shock cooling of fruit after harvest reduced adverse changes in fruit quality after storage in CA cold storage and shelf life. They were firmer, more puncture resistant, and retained more L-ascorbic acid and polyphenols. After 6 weeks of cold storage in CA, eight types of fungi and molds were found that caused the mycotoxins patulin, deoxynivalenol, and zearalenone were found in the fruit of all cultivars. Fruits of the Ken’s Red cultivar were the most firm and puncture resistant, the darkest, and contained the most anthocyanins and the least L-ascorbic acid. In contrast, fruits of the cultivar Sientaibrskaja were the least suitable for storage and transport.

Non-invasive monitoring of red blood cells during cold storage using handheld Raman spectroscopy.

The current best practices allow for the red blood cells (RBCs) to be stored for prolonged periods in blood banks worldwide. However, due to the individual-related variability in donated blood and RBCs continual degradation within transfusion bags, the quality of stored blood varies considerably. There is currently no method for assessing the blood product quality without compromising the sterility of the unit. This study demonstrates the feasibility of monitoring storage lesion of RBCs in situ while maintaining sterility using an optical approach. A handheld spatially offset Raman spectroscopy (RS) device was employed to non-invasively monitor hemolysis and metabolic changes in 12 red cell concentrate (RCC) units within standard sealed transfusion bags over 7 weeks of cold storage. The donated blood was analyzed in parallel by biochemical (chemical analysis, spectrophotometry, hematology analysis) and RS measurements, which were then correlated through multisource correlation analysis. Raman bands of lactate (857 cm-1 ), glucose (787 cm-1 ), and hemolysis (1003 cm-1 ) were found to correlate strongly with bioanalytical data over the length of storage, with correlation values 0.98 (95% confidence interval [CI]: 0.86-1.00; p=.0001), 0.95 (95% CI: 0.71-0.99; p=.0008) and 0.97 (95% CI: 0.79-1.00; p=.0004) respectively. This study demonstrates the potential of collecting information on the clinical quality of blood units without breaching the sterility using Raman technology. This could significantly benefit quality control of RCC units, patient safety and inventory management in blood banks and hospitals.

Application of Lactobacillus helveticus CNRZ 32 to Control the Microbial Contaminants in Cheese by Addition of Bacterial Extracts or by In Situ Production of Bioactive Metabolites

Microbial spoilage of cheese represents a major concern from both health and economic views. The addition of food preservatives is considered the most applied strategy to ensure food quality and to control microbial contamination. It well established that natural preservatives such as Nisin and Natamycin are of great effectiveness against a wide range of microbial concerns, but the lack of wide spectrum effect induces looking for more efficient alternatives. This research suggests alternative treatments to be evaluated side by side with both Nisin and Natamycin within real cheese models to control microbial contamination during the storage period. To evaluate this, two varieties of cheese were manufactured and inoculated with a set of pathogen and cheese spoiling microorganisms. Talaga cheese batches were separately treated with extract of MRS that previously fermented by Lactobacillus helveticus CNRZ 32, Nisin and Natamycin at Free State and Chitosan Nanoparticles-loaded state to become 6 treatments (T1 – T6) other than the control (C). The same treatments were applied to Karish cheese batches, in addition to inoculation of Lactobacillus helveticus CNRZ 32 1% (v/v) in the seventh batch. Upon microbiological analyses, results show that T2; the extract loaded on Chitosan Nanoparticles completely reduced the count of all pathogens and spoiling populations after two weeks of cold storage (2 – 6oC) in Talaga cheese. In the case of Karish cheese, the 7th batch treated with Lactobacillus helveticus CNRZ 32 inoculation had no pathogenic nor spoiler growth after one week of cold storage (2 – 6oC). These results suggest that Lactic acid bacteria especially Lactobacillus helveticus CNRZ 32 can efficiently ensure the safety and quality of cheese if applied in appropriate form.

Effect of initial moisture content and sample storage duration on compost stability using the ORG0020 dynamic respiration test

Biological tests are widely used to assess composting process status and finished material stability. Although compost stability is known to be influenced by moisture content (MC) and storage duration, there is a lack of data supporting boundary limits for standardised testing. Using the ORG0020 dynamic respiration test we assessed the stability of materials from different commercial composting sites processing only green waste or mixed green and food waste. Samples were tested at three different MC following adjustment with the ‘fist’ test within the range 40–60%. The results showed manipulation of MC within this range could have significant impact on measured stability for some but not all samples. Two samples reported significantly higher activity when MC was manipulated from ~50% to ~60%. For storage duration, samples showed significant decrease in measured activity over several weeks of cold storage. However, there was no significant difference in stability for samples tested up to nine days from receipt. The results of this research will support decisions relating to the boundary limits for moisture content and storage time for the ORG0020 test. The results will also provide insight to the wider range of biological tests used to assess compost stability.

Different sequence of high-hydrostatic pressure and mild-heat treatment on the colour and sensory characteristics of strawberry puree

AbstractThe effect of high pressure processing (300 and 600 MPa) combined with mild heat treatment (55 and 75 °C) on the colour parameters, anthocyanin content, and sensory characteristics of strawberry puree were examined after the treatments and 2 weeks of cold storage at 2 and 15 °C. As on an industrial scale the simultaneous implementation of these treatments remains a challenge, the HHP and heat treatments were carried out consecutively in different sequences. The colour parameters and the anthocyanin content did not change significantly due to the treatments, but decreased during cold storage, at 15 °C storage the changes were more intensive than at 2 °C. Regarding the sensory test results, the different sequence of the 600 MPa-75 °C combined treatments is not detectable even after 2 weeks of storage at 15 °C, but in case of 300 MPa-55 °C, the enzyme inactivation is probably not sufficient enough as differences between the samples were detected.

Effect of modified atmosphere packaging on selected functional characteristics of Agaricus bisporus

Mushrooms are proven as a functional food due to their numerous beneficial effects on human health. Contemporary consumers purchase cultivated mushrooms that spend some time on the shelf, which makes it questionable whether this food can still be called “functional”. An examination was performed on selected characteristics of white and brown (Portobello) Agaricus bisporus stored in commercial (air) and three modified atmosphere packagings (MAP): high nitrogen, low carbon dioxide and low oxygen packaging. The amount of ascorbic acid decreased throughout 22 days for both varieties, especially in the white variety stored in commercial packaging. Similarly, total flavonoids decreased, although not to a significant degree. Metal chelating ability was pronounced throughout the storage period, with minor changes in the case of the brown variety. Diabetes-connected enzymes were inhibited by A. bisporus, while inhibition was significantly higher toward α-amylase. Nitrogen-rich packaging suppressed α-amylase and stimulated α-glucosidase in the white strain. Both the commercial packaging and the MAP samples exhibited changes in their functional characteristics over three weeks of cold storage. MAP, especially the low oxygen packaging, provided the best option for the preservation of the majority of functional characteristics examined in this research. Enzymes activities appeared to be more specifically tuned, and dependent on parameters not covered here. Brown variety was more resistant to environmental changes with respect to its functional characteristics.

QUALITY CHARACTERISTICS OF FRESH AND FROZEN MEAT FROM RABBITS FED DIFFERENT LEVELS OF GLIRICIDIA SEPIUM

This study compares the effects of different levels (0 to 50%) of Gliricidia sepiun leaves on the processing, proximate composition, and organoleptic characteristics of male and female rabbits using a 3 x 2 x2 factorial design. The effect of 8 weeks of cold storage at - 20+20 C on acceptability of the rabbit meat was also evaluated. The data obtained showed that the live-weight, dressing percentage, and fat content of the rabbits fed 25% Gliricidia sepium were higher than those from 0 % (control) or 50 % level at 10 weeks old. The total cooking losses were higher by 15 to 24% in the frozen roasts, due mainly to increased drip and evaporative losses which were also slightly higher in the female carcasses. The expressible moistrue index (EMI) increased in the frozen samples, and no significant difference (P&gt;0.05) was found to be attributable to diet. The final moisture content and cook yield of the frozen samples decreased, whereas the ash content was not significantly affected by sex or diet. However, the protein and fat contents, and pH increased regardless of sex in all the cooked samples. The sensory evaluation results are suminarized as follows: (1) fresh roasts from rabbits fed 25% Gliricidia sepiun were preferred, possibly, influenced by tenderness scores and slightly higher fat content; and (2) meat roasts from the frozen samples did not differ on overall acceptability, although the palatability scores diminished at the end of 8 weeks of frozen storage, and panelists did not detect any significant differences (P&gt;0.05) attributable to diet or sex.

Enhancing quality and safety of raw buffalo meat using the bioactive peptides of pea and red kidney bean under refrigeration conditions

The aim of this study was to extend the shelf life of raw buffalo meat by coating with high solubility bioactive peptides (BPs). In this work, BPs (11S) of pea and red kidney beans were obtained by different isolation techniques. Alcalase-red kidney bean hydrolysate (RBAH) successfully obtained after 60 min enzymatic hydrolysis for red kidney bean protein isolate (RPI) by Alcalase (E/S ratio of 1:100, hydrolysis degree 30%). The 11S pea globulin (11SGP) was isolated from pea total protein by ammonium sulphate. BPs were characterised by SDS-PAGE and used as a shield coated raw buffalo meat because of their basic nature. The isolated peptides have considerable antioxidant and antimicrobial activity. The antioxidant activity was estimated by DPPH assay. The antibacterial activity was evaluated by well diffusion assay; however, antifungal activity was estimated by disc diffusion assay. RBAH and 11SGP (800 µg/mL) were significantly (p ≤ .05) scavenged 90, 92% of DPPH˙, however, 60 µg/mL concentration was significantly (p ≤ .05) reduced 48–89% of gram-positive, and 38–82% of gram-negative bacteria, respectively, and they were inhibited 88% of fungal growth. The BPs (400 µg/g) were significantly reduced (p ≤ .05) the increment of meat pH and myoglobin oxidation to an acceptable percentage of metmyoglobin (MetMb) (40%) for 15–20 d via eliminating 44% of bacterial load and maintained secured storage for two weeks. RBAH was significantly increased (p ≤ .05) a*, and b* values and enhanced the meat redness, but a* value was decreased during storage. RBAH and 11SGP (400 µg/g) (p ≤ .05) was maintained the meat colour and odour by 48–68% and 64–73% after two weeks of cold storage, respectively. The tested peptides could be safely applied in novel foods. Highlights 11SGP and RBAH are high solubility bioactive peptides (BPs) with antioxidant and antimicrobial activity. 11SGP and RBAH reduce myoglobin oxidation to an acceptable percentage of met-myoglobin. RBAH enhances the whiteness and redness of buffalo meat. 11SGP and RBAH extend meat shelf life for a period exceeds 15 d at 4 °C. Graphical

Mechanical Characterization of Biopolymer-Based Hydrogels Enriched with Paulownia Extracts Recovered Using a Green Technique

This study deals with the development and mechanical characterization of innovative starch- and gelatin-based hydrogels enriched with hydrothermal aqueous extracts from Paulownia (i.e., bark, leaves, petioles). The color, rheology, and texture properties of formulated biopolymer-based hydrogels depending on the processing conditions of the extracts was evaluated for the different Paulownia fractions. Results indicated that a clear impact on color features of the tested hydrogels was observed with the incorporation of Paulownia extracts. Rheological testing showed that weak and intermediate strength hydrogels were identified for starch- and gelatin-based hydrogels independently of used extract. A relevant softening of all gelled matrices was observed in the presence of recovered liquor extracts involving the following trend (leaves &gt; barks &gt; petioles). For all fractions, the highest viscoelastic features were achieved for hydrogels made with extracts recovered at 140 °C. Texture outcomes confirmed the rheological achievements. No syneresis was observed in developed hydrogels after two weeks of cold storage.