Days Of Cold Storage Research Articles

Influence of Cold Storage on Pear Physico-Chemical Traits and Antioxidant Systems in Relation to Superficial Scald Development.

Superficial scald is the most common physiological disorder in apples and pears and causes huge economic losses worldwide. The aim of this study is to determine the different scald susceptibilities of seven pear cultivars/selections during five months of cold storage (CS). Four advanced pear selections and three commercial cultivars were harvested from an orchard located in Emilia-Romagna region, and cold stored at −1 °C and 85% relative humidity (RH).After 90, 120, and 150 days, fruits of each cultivar and selection were removed for ripening for 4 d, after which scald damage, physico-chemical and nutraceutical traits, and enzymatic antioxidant systems were evaluated on peel and pulp. ‘Abbé Fétel’, ‘Falstaff’, and ‘CREA 171’ did not showed superficial scald symptoms after 90 days, while ‘Doyenne du Comice’ and ‘CREA 264’ showed the highest susceptibility. After 90 days, CS ‘Falstaff’ and ‘CREA 179’ showed the highest total polyphenol content (TPH) in peel, followed by ‘Doyenne du Comice’ and ‘AbbéFétel’; lowest TPH was detected in ‘CREA 264’. After 120 and 150 days of CS, ‘Abbé Fétel’ and ‘CREA 171’ showed the highest peel TPH. ‘CREA 264’ and ‘CREA 125’ reached the lowest values of TPH during the three CS time periods. Superoxide dismutase and catalase activities were higher in the peel of scald-resistant than that in scald-susceptible pear cultivars/advanced selections. Superficial scald induced an increase in polyphenoloxidase, and guaiacol peroxidase activities involved in fruit-browning during CS. Furthermore, we observed an increase in lipoxygenase activity and consequent membrane damage in both the peel and flesh of the fruit. This study indicates that pear cultivars/advanced selections have different superficial scald susceptibilities that enable them to induce the activity of several antioxidant enzymes, following CS.

Preservation treatment of fresh raspberries by e-beam irradiation

E-beam irradiation was studied as a post-harvest treatment for red raspberries (Rubus idaeus L.). Microbial inactivation (natural microbiota and potential pathogenic bacteria) and bioactive properties (phenolic content, vitamin C content and antioxidant activity and cytotoxicity) of these fruits were evaluated before and after irradiation and during storage of 14 days at 4 °C. A reduction of 2 log CFU/g of mesophilic bacteria and 3 log CFU/g on filamentous fungi, and no detection of foodborne inoculated pathogens (3 log CFU/g) was achieved with an e-beam treatment at 3 kGy and during 7 days of refrigerated storage. Regarding bioactive properties, the results suggested that irradiation could preserve the phenolic content and antioxidant activity of raspberries through 7 days of cold storage, even though a decrease of 80% on ascorbic acid concentration was observed. Furthermore, no in vitro inhibitory effect on human cells lines was observed for the extracts from e-beam-treated raspberries. The overall results suggested that use of e-beam irradiation as post-harvest treatment of raspberries as an emergent, clean and environmental friendly process to extend the shelf-life of this fruit with safety and preservation of bioactivity. Industrial relevanceRed raspberries are known to demonstrate high bioactivity that could be beneficial to human health, but are highly perishable and often associated with foodborne outbreaks, which makes its safety and commercialization a challenge. The use of a terminal control such as irradiation might reduce the burden of disease transmission and extend the quality of fresh red raspberries. The present research indicated that e-beam irradiation can be used as post-harvest treatment of raspberries, guarantying its safety and quality with the add-value of shelf-life extension.

Covalent Immobilization of Polypeptides on Polylactic Acid Films and Their Application to Fresh Beef Preservation

To enhance the advantage of a long-term stability and low-toxicity active packaging system, two biodegradable covalent immobilized antibacterial packaging films were developed and applied to fresh beef preservation in this study. A polylactic acid (PLA) film was prepared by the extrusion-casting method. The surface of the PLA film was modified with plasma treatment to generate carboxylic acid groups, and then antibacterial agent nisin or ε-poly lysine (ε-PL) was covalently attached to the modified film surface. Physical, chemical, and antimicrobial properties of films were then characterized. Scanning electron microscopy and water contact angle images confirmed that nisin or ε-PL was successfully grafted onto the film surface. The values of protein loading on the nisin-g-PLA film and ε-PL-g-PLA film were 5.34 ± 0.26 and 3.04 ± 0.25 μg of protein/cm2 on the surface. Microbial analysis indicated that the grafted films effectively inhibit the growth of bacteria. Finally, the effects of the nisin-g-PLA film or ε-PL-g-PLA film on physicochemical changes and microbiological counts of fresh beef during cold storage at 4 °C were investigated. The total viable count of the control sample exceeded 7 logarithms of the number of colony forming units per gram (log CFU/g) after 11 days of cold storage (7.01 ± 0.14 log CFU/g) versus 15 days for the ε-PL-g-PLA film (7.37 ± 0.06 log CFU/g) and the nisin-g-PLA film (6.83 ± 0.10 log CFU/g). The results showed that covalent immobilized antibacterial packaging films had positive impacts on the shelf life and quality of fresh beef. Therefore, a covalent immobilized antibacterial packaging system could be a novel preservative method for foods.

Novel postharvest management using laser irradiation to maintain the quality of strawberry

Strawberry fruits are perishable fruits and deteriorate vastly after harvest. This study aimed to maintain the quality attributes of strawberry fruit during seven days of cold storage using diode laser irradiation. Strawberries (Fragaria × ananassa, cv. Festival) were irradiated with diode laser at wavelength of 450 nm and light intensity of 1.3 mWcm−2 for 3, 6, and 12 min, while the non-irradiated fruits served as the control sample, then the fruit was packed and stored for 7 days at 10 °C and 85–90% relative humidity. The findings showed a significant reduction in weight loss and decay percentages of treated strawberries with 3 and 6 min of laser light, while control and 12 min laser irradiated samples exhibited the highest significant increase in weight loss and fungal decay. All laser treatments retained firmness of the flesh until the fifth day of storage, meanwhile the control sample became softer and fully mature, and at the end of the storage period, the control sample lost 77.9% of the firmness compared to 9.94% of 3 min treated fruit. Laser light had a marginal effect on pH, titratable acidity, and the content of anthocyanin. The results revealed that low exposure duration of laser treatment decreased darkness, and Chroma and total soluble solids (TSS) were maintained. Vitamin C showed a slight increase for all treatments and by the end of the storage period, the 3 min treated sample had the highest significant value of 73.04 mg/100 g compared to the lowest significant value of 65.86 mg/100 g of control. It was noticed that laser irradiation significantly reduced the reduction percentage of antioxidant activity compared to the control sample even with the highest exposure time of laser irradiation.

Effect of gamma irradiation and subsequent cold storage on the development and predatory potential of seven spotted ladybird beetle Coccinella septempunctata Linnaeus (Coleoptera; Coccinellidae) larvae

Seven spot ladybird beetle, (Coccinella septempunctata) is a widely distributed natural enemy of soft-bodied insect pests especially aphids worldwide. Both the adult and larvae of this coccinellid beetle are voracious feeders and serve as a commercially available biological control agent around the globe. Different techniques are adopted to enhance the mass rearing and storage of this natural enemy by taking advantage of its natural ability to withstand under extremely low temperatures and entering diapause under unfavorable low temperature conditions. The key objective of this study was to develop a cost effective technique for enhancing the storage life and predatory potential of the larvae of C. septempunctata through cold storage in conjunction with the use of nuclear techniques, gamma radiations. Results showed that the host eating potential of larvae was enhanced as the cold storage duration was increased. Gamma irradiation further enhanced the feeding potential of larvae that were kept under cold storage. Different irradiation doses also affected the development time of C. septempuntata larvae significantly. Without cold storage, the lower radiation doses (10 and 25 GY) prolonged the developmental time as compared to un-irradiated larvae. Furthermore, the higher dose of radiation (50GY) increased the developmental time after removal from cold storage. This study first time paves the way to use radiation in conjunction with cold storage as an effective technique in implementation of different biological control approaches as a part of any IPM programs

Overall quality and oxidative damage in packaged freshly shelled walnut kernels during cold storage

In this study, the effect of passive- and active-modified atmosphere packaging (PMA and MAP with 70% N2 and 30% CO2) using semipermeable and barrier films on physicochemical and enzymatic properties and quality of freshly shelled walnut kernels stored at 6 °C for 18 days were investigated. Changes in physicochemical such as free fatty acidity content, peroxide value, colour and enzymatic traits such as polyphenol oxidase, lipoxygenase were tracked in the fresh kernels during cold storage in different packaging systems. The MAP system inhibited polyphenol oxidase activity, delayed browning of tegumented kernels, and helped in maintaining a high total polyphenol content. The PMA system preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation with values of 3.26 ± 0.05 nmol hydroperoxides min−1 g−1 dry weight and 10.90 ± 0.50 nmol g−1 dry weight, respectively after 18 days of cold storage. Moreover, this system inhibited free fatty acid formation and it was characterised by lower peroxide values with 5.17 ± 0.04 mEq O2 kg−1 oil at the end of storage. Principal component analysis provided a global view of the differential qualitative responses of fresh walnut kernels in different packaging systems during cold storage. Our results show that packaging systems could be utilised to extend postharvest shelf life, improve qualitative traits, and inhibit enzyme-mediated browning of fresh kernel walnuts during cold storage.

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.