Days Of Cold Storage Research Articles

Extending the shelf life and maintaining quality of minimally-processed pomegranate arils using ascorbic acid coating and modified atmosphere packaging

Demand for minimally processed ready-to-eat pomegranate arils increased in the market over the past decade due to their high nutritional value, sensory characteristics, convenience, and health benefits. The objective of this study was therefore to investigate the effect of ascorbic acid coating and modified atmosphere packaging (MAP) on the physicochemical, microbiological, sensory quality characteristics and shelf life of pomegranate arils Shishe-Kab cultivar. Treatments were: passive-MAP, passive-MAP (washed arils with water), active-MAP1 (35.2% O2, 0.3% CO2, 64.5% N2), active-MAP2 (15.5% O2, 20% CO2, 64.5% N2), active-MAP1 + ascorbic acid, and active-MAP2 + ascorbic acid. The results indicated that experimental treatments significantly influenced some of the physicochemical parameters of pomegranate arils as pH and redness increased. A combination of active packaging (MAP1 and MAP2) and ascorbic acid coating preserved the redness of arils and had higher a* values compared to control and other treatments after 20 days of cold storage. Interestingly, samples packed in active-MAP with or without ascorbic acid coating helped to keep the sensory qualities with acceptable eating quality, as well as significantly extended the shelf life (about 30%) of pomegranate arils ‘Shishe-Kab’ cultivar in refrigerated storage at 3 °C compared to passive MAP. In conclusion, the results revealed that higher O2 or CO2 concentration than air in packages (active-MAP) alone and plus ascorbic acid coating can prolong the lag time of microorganisms and extend the shelf life of pomegranate arils more than 20 days during cold storage at 3 °C. Overall, sensory scores were also higher in ascorbic acid coated arils that were quite acceptable even after 20 days of storage at 3 °C.

Probiotic Fermented Milk with Collagen

The aim of this study was to assess the possibility of using collagen protein hydrolysate in the production of milk fermented by Bifidobacterium animalis ssp. lactis Bb-12 and Lactobacillusrhamnosus. Physicochemical and organoleptic properties were studied and microbiological analysis of fermented milk was performed on days 1 and 21 of storage. Milk with the addition of 3% collagen protein hydrolysate was pasteurized (85 °C/30 min), divided into two groups, cooled to 37 °C and inoculated: the first group with Bifidobacteriumanimalis ssp. lactis Bb-12, second with Lactobacillus rhamnosus. Incubation was carried out at 37 °C/10 h. After 21 days of refrigerated storage, the pH value decreased in all analyzed milk samples. Collagen protein hydrolysate was a good milk additive to increase gel hardness and reduce syneresis. Moreover, its addition did not change the taste and odour of milk fermented with the use of Bifidobacterium Bb-12 and Lactobacillus rhamnosus. Collagen protein hydrolysate favourably stimulated the survival of Bifidobacterium Bb-12 during 21 days of storage. After 21 days of cold storage in milk with collagen, the number of Lactobacillus rhamnosus cells was reduced by 0.11 log cfu g−1.

Design and Characterization of a Novel Fermented Beverage from Lentil Grains.

The experimental activities carried out in this study aimed at designing a lentil-based beverage rich in soluble and digestible proteins. In order to extract soluble proteins, lentil grains were soaked in water overnight, blended, treated with proteolytic enzymes and fermented with Lactobacillus strains. Protein enzymatic hydrolysis, carried out with four commercial food grade enzyme preparations, showed that bromelin, at the enzyme to substrate ratio of 10%, was the best solution to produce this novel beverage. Even though the seven Lactobacillus strains were all able to ferment aqueous extract within 24 h, L. acidophilus ATCC 4356, L. fermentum DSM 20052 and L. paracasei subsp. paracasei DSM 20312 showed the highest growth rate and the lowest pH values. In fermented lentil-based beverages, the antinutritional factor phytic acid decreased up to 30%, similarly, the highest reduction in raffinose oligosaccharides content reached about 12% the initial concentration. It is worthy of note that the viable density of all strains remained higher than 7 log cfu/mL after 28 days of cold storage. The results here reported show for the first time the possibility to obtain a probiotic lentil-based beverage rich in soluble proteins, peptides and amino acids with low content in main antinutritional factors.

Effects of Biostimulants on Annurca Fruit Quality and Potential Nutraceutical Compounds at Harvest and during Storage.

The cultivar Annurca is an apple that is cultivated in southern Italy that undergoes a typical redding treatment and it is appreciated for organoleptic characteristics, high pulp firmness, and nutritional profile. In this study, the effects of three different biostimulants (Micro-algae (MA), Protein hydrolysate (PEP), and Macro-algae mixed with zinc and potassium (LG)), with foliar application, on the quality parameters of Annurca apple fruits at the harvest, after redding, and at +60 and +120 days of cold storage were analyzed: total soluble solids (TSS) content, total acidity (TA), pH, firmness flesh, and red coloration of epicarp. Additionally, the polyphenolic quali-quantitative profile of pulp and peel was analyzed by UHPLC-Q-Orbitrap HRMS and Folin-Ciocalteu and the antioxidant capacity with the methods 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric-reducing antioxidant capacity (FRAP). The results obtained suggest that biostimulants are involved in the regulation of the secondary metabolism of the treated plants, acting positively on the quality of the Annurca fruits and their nutritional value. Fruits treated with PEP have shown, during cold storage, a significantly higher content of total polyphenols in flesh and a higher concentration of phloretin xylo-glucoside and phloridzin (350.53 and 43.58 mg/kg dw respectively). MA treatment caused, at the same time, an enhancement of flavonols between 0.6–28% and showed the highest total polyphenol content in the peel after 60 and 120 days of cold storage, with 2696.048 and 2570.457 mg/kg dw, respectively. The long-term cold storage (120 days) satisfactorily maintained phenolic content of fruits deriving from MA and PEP application, in accordance with data that were obtained for peel, showed an increase of 7.8 and 5.8%, respectively, when compared to the fruits cold stored for 60 days. This study represents the first detailed research on the use of different types of biostimulants on the quality of the Annurca apple from harvest to storage.

In situ Listeria monocytogenes biocontrol and sensory attributes enhancement in raw beef meat by Enterococcus lactis

The enterocin P-producing Enterococcus lactis strain Q1 was directly added at 107 CFU/g in refrigerated raw beef to evaluate its effectiveness in the control of Listeria monocytogenes EGDe 107776 proliferation. Furthermore, sensorial evaluation of the quality of treated beef meat samples with the enterococcal protective culture was performed basing on color, odor, and appearance parameters for 14 days. As a result, it was demonstrated that the enterocin P-producing E. lactis Q1 strain led to a remarkable reduction (p < .05) of L. monocytogenes in beef meat by 6.47 ± 0.30 log units after 7 days and 7.25 ± 0.35 log units below the control after 14 days, then remained stable up to 28 days of cold storage. Also, E. lactis Q1 strain improved significantly (p < .05) the organoleptic quality of treated beef sample. Hence, E. lactis Q1 clearly indicates its efficiency to be used as protective agent in a wide range of meat products. Practical applications Preserving meat using new bacteriocinogenic lactic acid bacteria is an important agenda to ensure consumer safety. The present study showed the ability of an enterocin P-producing strain named E. lactis Q1, added in raw beef meat during cold storage, to inhibit L. monocytogenes and improve meat sensory properties. Hence, E. lactis Q1 can be used in the future to develop healthy meat products with better shelf life and quality.

Effects of Frozen Storage on the Physical Properties and Sensory Acceptability of Goat’s Milk Yoghurt

The effects of frozen storage of goat’s milk on the physicochemical, physical properties, and sensory attributes of goat’s milk yoghurts were evaluated. Four yoghurts were made from goat’s milk stored at 4℃ overnight, and at -6, -20, or -35℃ for 1 month. Goat’s milk yoghurts were stored at 6℃ for 21 days. Protein and lipid contents in all the yoghurts were insignificantly different, however, the total solids content, including the added sugar in the yoghurts made from frozen goat’s milk, significantly increased in comparison with that in the yoghurt made from chilling goat’s milk. The water holding capacity (WHC) and viscosity for all the yoghurts at any period of cold storage were statistically different. No significant differences in pH or titratable acidity for all the yoghurts were observed after 1 day of cold storage; however, these physicochemical properties for the yoghurts after 7 days of storage were significantly different. All the yoghurts after 21 days of storage received similar scores for appearance and texture, but significantly different scores for color, odor, flavor, and overall acceptability.

Quality and Storage Ability of Fresh-Cut Pepper Treated by 1-Methylcyclopropene

Abstract The study was conducted to assess the effect of 1-methylcyclopropene (1-MCP) treatment on the storage ability of fresh-cut pepper fruit. The cut fruit of pepper ‘Yecla F1’ were treated immediately after cutting and ‘Roberta F1’ before cutting. The 1-MCP at the concentrations of 1.0 μl·dm−3, 3.0 μl·dm−3, and 5.0 μl·dm−3 was applied to gas-tight containers with fruit for 20 hours at 20 °C. Peppers were stored at two temperatures: 0 °C and 5 °C, for up to 8 days. The treatment applied immediately after cutting slowed down the softening of pepper a little when fruit was stored at 0 °C, as well as during subsequent shelf life. The treatment applied before cutting did not reduce the softening, discoloration as well as rotting of pepper strips in cold conditions and shelf life. The sensory evaluation showed that 1-MCP treatment, applied before or after cutting, did not improve the quality of fresh-cut pepper during short term storage. The ethylene concentration after 4 days of cold storage was higher inside the bags with treated fresh-cut pepper, as compared to the bags with untreated samples. These results can give important direction for pepper fruit storage.

Different growing conditions can modulate metabolites content during post-harvest of Viola cornuta L. edible flowers

Edible flowers are inflorescences traditionally used in various part of the world to enrich sweet and savoury recipes. The flowers of Viola spp. were appreciated since the Romans, and today the fresh products are now incorporated as ingredients in different culinary preparations. In this work, cultivation of potted Viola cornuta L. cv. Penny Lane was performed in greenhouse with different environmental conditions (basal heating, additional LED lighting and moisture management) and therefore the biomass production (number of flowers per square meter and plant dimension per pot) was assessed. The plants are characterised by flowers with dark purple and orange petals in the same corolla. The shelf-life of detached flowers was studied in post-harvest conditions at 0 and 4 days of cold storage at 4°C (polyethylene boxes, 12/12 h light/dark condition) to simulate the condition of I gamma products. Sugars and secondary metabolites were analysed. Basal heating seems not to increase flower number but could contribute to reach a well-balanced simultaneous presence of different antioxidant molecules (polyphenols, anthocyanins, carotenoids). Our data highlight that the short cold storage under light condition lead to an increase in the content of total polyphenols and antioxidant activity, although a general reduction in pigments and sugars is observed.

Structure and Function of Porcine Arteries Are Preserved for up to 6 Days Using the HypoRP Cold-storage Solution.

Maintaining functional vessels during preservation of vascularized composite allografts (VCAs) remains a major challenge. The University of Wisconsin (UW) solution has demonstrated significant short-term benefits (4-6 h). Here we determined whether the new hypothermic resuscitation and preservation solution HypoRP improves both structure, survival, and function of pig arteries during storage for up to 6 days. Using porcine swine mesenteric arteries, the effects of up to 6-day incubation in a saline (PBS), UW, or HypoRP solution on the structure, cell viability, metabolism, and function were determined. After incubation at 4°C, for up to 6 days, the structures of the arteries were significantly disrupted, especially the tunica media, following incubation in PBS, in contrast with incubation in the HypoRP solution and to a lesser extent, in UW solution. Those disruptions were associated with increased active caspase 3 indicative of apoptosis. Additionally, while incubation in PBS led to a significant decrease in the metabolic activity, UW and HypoRP solutions allowed a stable to increased metabolic activity following 6 days of cold storage. Functional responsiveness to phenylephrine (PE) and sodium nitroprusside (SNP) decreased over time for artery rings stored in PBS and UW solution but not for those stored in HypoRP solution. Moreover, artery rings cold-stored in HypoRP solution were more sensitive to ATP. The HypoRP solution improved long-term cold storage of porcine arteries by limiting structural alterations, including the collagen matrix, reducing apoptosis, and maintaining artery contraction-relaxation functions for up to 6 days.

Caracterização física e físico-química de Iogurte Caprino Prebiótico Adicionado de Geleia de Mandacaru e Maracujá

Objetivou-se com a pesquisa, elaborar iogurte caprino prebiótico adiciona de geleia da polpa do fruto de mandacaru e do maracujá e, posteriormente, realizar análises físicas e físico-químicas. Foram processados 2 tratamentos de iogurtes caprinos adicionados de 15% de geleia de mandacaru (Cereus jamacaru) e maracujá (Passiflora edulis Sims.), a citar: IC (Iogurte Caprino Controle), adicionado da cultura starter Streptococcus salivarius subsp. thermophillus e IPREB (Iogurte Caprino Prebiótico), adicionado da fibra prebiótica oligofrutose (FOS), além da cultura starter. Os tratamentos foram submetidos a análises físicas e físico-químicas, o processamento dos iogurtes foi realizado em triplicata, os quais foram analisados nos tempos 1, 7, 14, 21 e 28 dias de armazenamento refrigerado (4 ±1 °C). Diante dos dados analisados, os iogurtes apresentaram propriedades físicas e físico-químicas adequadas ao produto. Para alguns parâmetros, houve influência da cultura utilizada; da fibra e da geleia, com destaque para os parâmetros de Acidez, pH e Lactose. Os resultados deste estudo apresentaram uma incorporação bem sucedida (cultura, FOS e geleia), como ingredientes a serem inseridos num novo produto lácteo caprino.

Avaliação sensorial de iogurte caprino prebiótico adicionado de geleia da polpa de mandacaru e maracujá

O iogurte é considerado uma boa fonte de proteína, cálcio, riboflavina e vitamina B12, que apresenta efeitos benéficos para os seres humanos. Diante do exposto, objetivou-se, com o presente estudo, elaborar um iogurte caprino prebiótico, adicionado de geleia do maracujazeiro (Passiflora edulis), e da polpa do mandacaru (Cereus jamacaru) e avaliar os parâmetros sensoriais. Para isso, foram desenvolvidas 2 formulações de iogurtes caprinos: IC (Iogurte Caprino Controle), adicionado da cultura starter Streptococcus salivarius subsp. thermophillus e Lactobacillus delbrueckii subsp. Bulgaricus e IPREB (Iogurte Caprino Prebiótico) adicionado da fibra prebiótica oligofrutose (FOS), além da cultura starter, todos iogurtes adicionados de 15% de geleia. O processamento dos iogurtes foram realizados em triplicatas e analisados nos tempos 1, 7, 14, 21 e 28 dias de armazenamento refrigerado (4 ±1 °C). Pode-se observar, a partir dos resultados encontrados que não houve diferença estatística (p&gt;0,05) entre as formulações, referente aos atributos aparência, cor, aroma, sabor, consistência e avaliação global. De modo geral, pode-se observar que todos os parâmetros sensoriais, as formulações foram bem aceitas, visto que as notas variaram entre os termos hedônicos “gostei moderadamente” (nota = 7) à “gostei muito” (nota = 8). Com isso, percebe-se que o desenvolvimento do iogurte caprino prebiótico adicionado de geleia de mandacaru e maracujá tem grande potencial de comercialização, agregando em um mesmo produto características funcionais e sensoriais atrativas.

Pasteurization of carrot juice by combining UV-C and mild heat: Impact on shelf-life and quality compared to conventional thermal treatment

The combination of UV-C radiation and mild heat (UV-H) treatment is a promising strategy for synergistically increasing microbial inactivation in low UV-transmitting juices. In this research, we explored the suitability of UV-H treatment in carrot juice pasteurization and its impact on juice quality during shelf-life compared to that of thermal pasteurization. UV-H treatment at 60 °C (3.92 J/mL, 3.6 min) enabled reductions of over 5 log10 cycles in the reference pathogens and a significant reduction in spoilage yeasts, bacteria, and bacterial spores. The activity of pectin methylesterase and polyphenol oxidase was reduced by UV-H treatment to levels close to those of low-temperature pasteurization (60 °C/18.1 min). The native population of total aerobic bacteria, lactic acid bacteria, and yeasts and molds of UV-H-treated juice remained undetectable during 29 days of cold storage. Furthermore, viscosity, cloud stability, and the color of fresh juice were better preserved by UV-H treatment than by thermal pasteurization throughout storage.Industrial relevanceThis study demonstrates that UV-H treatment is a beneficial alternative to conventional thermal processing in carrot juice pasteurization, since appropriate inactivation levels of pathogenic and spoilage microorganisms can be reached while better preserving the quality attributes of fresh juice throughout its shelf-life.

Effect of 1-methylcyclopropene (1-MCP) application and periodic cold storage on ripening of “Bartlett” pear during ambient shelf life periods

Bartlett pears harvested at commercial maturity (10.64 kg/cm2 flesh firmness and 3.15 starch iodine rating) were fumigated with 1-methylcyclopropene (3.3%VP SmartFreshTM) in a concentration range of 100–1,000 nl/L inside airtight chambers. The fruit were stored under cold storage conditions (2 ± 1°C with 95 ± 2%) followed by ambient holdings after monthly intervals. Treated fruit had significantly (p < .05) highest flesh firmness, total soluble solid, ascorbic acid, phenols, sensory scores with lowest PLW, spoilage, calcium content, and respiration rate. Further, fruit treated with 1,000 nl/L 1-MCP retained edible quality during the successive ambient holding period of 15, 9, 6, and 3 days after 30, 60, 90, and 120 days of cold storage. The untreated control fruit after 30 and 60 days of cold storage could be stored only up to 9 and 3 days under ambient holding conditions and lost their sensory acceptability after 90 days of cold storage. Practical Applications Response of pear fruit to 1-MCP treatments is highly variable based on storage atmosphere, mode of application, and concentration of the active ingredient. In our findings, we reported that fumigating freshly harvested pears with 800, 900, and 1,000 nl/L 1-MCP for 24 hr in airtight chambers retained highest fruit quality. Further, fumigation facilities can be established near production areas and fruit can be treated with 800 nl/L 1-MCP with a shelf life of 15, 9, 6, and 3 d after 30, 60, 90, and 120 days of cold storage. Threshold acceptability values for the most important quality parameters, namely, TSS, firmness, and PLW were standardized which can be used in the future to predict the shelf-life period of the fruit.

Harvest Season and Genotype Affect Head Quality and Shelf-Life of Ready-to-Use Broccoli

Pre-harvest climatic conditions and genotype may have important effects on head quality and post-harvest performance of fresh-cut broccoli. The present work evaluates the effect of the growing cycle (summer–autumn (SA), winter (W), winter–spring (WS), and spring (S)) and genotype on qualitative (dry matter, concentration of chlorophylls, carotenoids, and color) and antioxidative (ascorbic acid, dehydroascorbic acid, total phenol concentrations, and antioxidant capacity) traits of broccoli heads and minimally processed florets. The WS raw product showed the best color indices (L* = 38.6, C* = 9.3 and h° = 123.8) as well as the highest chlorophyll (0.23 µg mg−1 fresh weight) but the lowest total phenol concentration (5.5 µg mg−1 dry weight - DW), whereas the ascorbic acid level (2.3 µg mg−1 DW) was comparable to or lower than that the other growing cycles. The WS florets confirmed their best visual quality, even showing an improved total phenol level after 14 days of cold storage. The climatic conditions experienced by broccoli plants grown in SA, W, and S periods were stressful as they resulted in a slight reduction in the visual quality of the heads, though only the SA florets showed a distinctive decay during storage. The lower post-harvest performance of SA grown broccoli was confirmed in all the tested cultivars, despite ‘Naxos’ seeming more tolerant. On the contrary, the greatest content of ascorbic acid (3.2 µg mg−1 DW) in the W heads and of phenols (11.1 µg mg−1 DW) in S heads was maintained during storage, thus preserving floret color.

The effect of brown rice flour on the quality of dangke nuggets during cold storage

Brown rice contains anthocyanin, which has an antioxidant activity that can inhibit the oxidation process in food during storage. This research aimed to determine the effect of brown rice flour levels substituting dangke on the quality of dangke nuggets for 14 days of cold storage. This research used a completely randomized design factorial pattern with two factors, i.e. the levels of brown rice flour (0%, 10%, and 20%) and the storage duration in the refrigerator (0 days, 7 days, and 14 days). The parameters analyzed included antioxidant activity with free radical scavenging activity DPPH method, pH and TBA values of dangke nuggets. The results showed that the levels of brown rice flour and storage duration had a very significant effect (P<0.01) on antioxidant activity, pH and TBA values of the product. The interaction between the two factors had a very significant effect (P<0.01) on the antioxidant activity and the TBA value of the product. The increased level of brown rice flour increased antioxidant activity and pH value; however, it decreased TBA value. Meanwhile, the increased storage duration increased antioxidant activity but decreased pH and TBA values of the product. Dangke nuggets with 10% and 20% brown rice flour levels had the same antioxidant activity on the 7th and 14th day of storage, and the same TBA value on the 14th day of storage. Dangke nuggets with 10% brown rice flour level could effectively inhibit the oxidation process of the product during 14 days of storage at cold temperatures.

Microbial Populations of Fresh and Cold Stored Donkey Milk by High-Throughput Sequencing Provide Indication for A Correct Management of This High-Value Product

Donkey milk is receiving increasing interest due to its attractive nutrient and functional properties (but also cosmetic), which make it a suitable food for sensitive consumers, such as infants with allergies, the immunocompromised, and elderly people. Our study aims to provide further information on the microbial variability of donkey milk under cold storage conditions. Therefore, we analysed by high-throughput sequencing the bacterial communities in unpasteurized donkey milk just milked, and after three days of conservation at 4 °C, respectively. Results showed that fresh donkey milk was characterized by a high incidence of spoilage Gram-negative bacteria mainly belonging to Pseudomonas spp. A composition lower than 5% of lactic acid bacteria was found in fresh milk samples, with Lactococcus spp. being the most abundant. The occurrence of microbial species belonging to risk group 2 was found in fresh milk. After three days of cold storage, the bacterial biodiversity of donkey milk was strongly reduced, since about 93% of the bacterial communities were identified as different species of psychrotrophic Pseudomonas. In conclusion, we report a preliminary description of the microbial diversity of donkey milk by using a metagenomic approach and encouraging a correct exploitation of this high-value niche product.

Probiotic Potential of Blueberry Jam Fermented with Lactic Acid Bacteria

The present study assesses the feasibility of blueberry as a raw substrate for the production of the probiotic blueberry jam by lactic acid bacteria (L. plantarum DB-2, L. fermentum J-1, P. acidilactici M-3, L. plantarum SK-3, and P. pentosaceus SM-2). Changes in pH, titratable acidity (lactic acid), cell survival, antioxidant properties, and in vitro cholesterol reduction properties of lacto- fermented as well as non-fermented blueberry jam were examined during fermentation and up to 28 days of storage. All the strains grew well in a lacto-fermented blueberry jam after 48 h fermentation. Set A (5.88 g/100 ml) and Set B (5.96 g/100 ml) produced less lactic acid than Set C (6.67 g/100 ml) which has the consortia of probiotic strains. After 28 days of cold storage, all the tested strains survived the low-pH conditions in lacto-fermented blueberry jam. The blueberry jam fermented with the consortia of probiotic strains (Set C) had a high antioxidant capacity (71.47 ± 3.57) in comparison with Set A, Set B, and control which showed anti-oxidant capacity viz. 70.52 ± 3.52, 70.25 ± 3.18, and 64.12 ± 2.47, respectively after 28 days of refrigerated storage. The lacto- fermented blueberry jam in Set C (58.48%) had shown the in vitro cholesterol-lowering ability better than Set B (18.87%) whereas Set A and control did not show any in vitro reduction in cholesterol level after 28 days of storage. Sensory quality studies were carried out after 28 days of storage. Sensory evaluation data showed the considerable acceptability of the lacto-fermented blueberry jam. Finally, we found that L. plantarum DB-2, L. fermentum J-1, P. acidilactici M-3, L. plantarum SK-3, and P. pentosaceus SM-2 are optimal probiotics for fermentation with blueberry jam. In this investigation, the results could be an indicator of the development of health-promoting fruit jam. This lacto-fermented blueberry jam is a low-cost healthy food product, provide better nutrition and good health to the population.

Graduated Controlled Atmosphere: A Novel Approach to Increase "Duke" Blueberry Storage Life.

Blueberries (Vaccinium corymbosum L.) are highly valued for their health-promoting potential, yet they are extremely perishable. Controlled atmosphere (CA) strategies reduce blueberry respiratory metabolism, slowing down senescence. However, the sudden change of atmosphere could elicit a physical abiotic stress in the fruit, negatively affecting quality. We propose an innovative approach based on controlled graduation to slowly reach optimum gas storage conditions as an alternative to standard CA. For two consecutive seasons, “Duke” blueberries were subjected to four different storage conditions: control (air); standard CA (sudden exposure to 5 kPa O2 and 10 kPa CO2 across the experiment); GCA3 and GCA7 (gradually reaching 5 kPa O2 and 10 kPa CO2 in 3 and 7 days, respectively). Fruit were stored for 28 days at 0 ± 0.5°C. Real-time respirometry provided an in-depth insight to the respiratory response of blueberries to their gas environment. Blueberries subjected to the graduated application of CA (GCA) treatments had a lower steady-state respiration rate compared to control and standard CA fruit. This indicated a reduction in metabolic activity that positively impacted quality and storage life extension. For example, GCA3 and GCA7 blueberries had a 25% longer storage life when compared to control, based on reduced decay incidence. In addition, GCA fruit were 27% firmer than control and CA fruit after 28 days of cold storage. GCA3 had a positive effect on maintaining individual sugars concentrations throughout the experiment, and both GCA treatments maintained ascorbic acid content close to initial values compared to a decrease of 44% in the control fruit at the end of the experiment. This work provides a paradigm shift in how CA could be applied and a better understanding of blueberry physiology and postharvest behavior.

Physicochemical Properties of White Soft Cheese Supplemented With Encapsulated Olive Phenolic Compounds

Background and Objective: White soft cheese is one of the most popular, high nutritional and healthy dairy products in Egypt. The Olive cake and mill waste-water are natural sources of phenolic compounds enriched with natural antioxidants. The aim of this work was the use of milk proteins as carriers for olive polyphenolic extract and its use it in the production of white soft cheese. Materials and Methods: polyphenols were extracted from olive mill waste. Maltodextrin (MD) with whey protein isolate (WPI) and skim milk powder (SMP) were used to entrap olive polyphenols extract. Encapsulation efficiency (EE), particle size, Zeta potential and electron microscopy for the prepared capsules were assessed. White soft cheese fortified with polyphenol capsules was made. The polyphenols content, antioxidant activity, texture profiles and sensory properties of cheese were followed. Results: The SMP/MD mixture gives better encapsulation efficiency of 90.08%, while the combination between MD with WPI at ratio 50:50 improved the encapsulation efficiency up to 88.42%. Capsules prepared with the use of SMP/MD mixture less mean diameter of 189 nm compared with using WPI: MD 50:50 which recorded 270.3 nm. Also, capsules prepared with SMP/MD mixture showed zeta potential of -39.75 mV while that prepared using WPI with MD showed -13.7 mV. Electron microscopy revealed that SMP capsules had diameter of 122.04 nm compared to 262.07 nm for WPI capsules. White soft cheese with fortification by olive polyphenols capsules had high total solids and protein contents and almost constant antioxidant activity during 30 days of cold storage. Hardness, gumminess, and chewiness of cheese fortified with polyphenols capsules increased significantly (P˂ 0.05) compared to control samples. Also, it gained higher total acceptability scores compared to control. Conclusion: Milk proteins can be used successfully to encapsulate olive polyphenols and polyphenols capsules can be used in the production of healthy white soft cheese.

Effects of Black Quinoa Wet-Milling Coproducts on the Quality Properties of Bologna-Type Sausages During Cold Storage.

The incorporation of a new ingredient into foods could not only affect the intrinsic properties of the product but also its shelf life. The aim of this study was to investigate the effect of the black quinoa (both as whole seeds and as the fibre-rich fraction obtained as coproduct from its wet-milling process) on the shelf life of Bologna-type sausages during cold storage. Three treatments of Bologna-type sausages were produced: control, sausages with black quinoa seeds (2.5%), and sausages with their fibre-rich fraction (2.5%). The effect of the black quinoa added on the physicochemical properties (pH and colour), lipid oxidation, residual nitrite level, and microbiological quality of Bolognas during 21 days of cold storage was evaluated. Although the addition of quinoa products in Bologna-type sausages modified some colour parameters (day 0), these differences were masked through the storage period. Sausages with quinoa products added showing lipid oxidation values lower than the control for all the days studied. Sausages with quinoa products added showed higher residual nitrite levels than control at all measurement times during the storage period. The addition of black quinoa did not affect microbial stability during storage. Black quinoa products can be considered promising ingredients to be used as antioxidants and natural nitrate sources in Bologna-type sausages without affecting their microbial safety during storage.