Days Of Shelf Life Research Articles

Effects of Plant Growth Regulators on Plum (Prunus domestica L.) Grown on Two Rootstocks at Harvest and at the Postharvest Period

Plant growth regulators (PGRs), such as cytokinins (6-benzyladenine; BA) and gibberellins (GAs), are widely used in fruit production. This study focused on the plum cultivar “Čačanska rodna” (P. domestica L.) grafted on vegetative rootstock “WaVit” and generative rootstock Prunus cerasifera, with interstock Prunus spinosa. PGR treatments included 50 mg L−1 and 100 mg L−1 of BA and 200 mg L−1 of gibberellin A3 (GA3) and non-treated control. Pomological characteristics of plum fruits were examined at harvest, while physicochemical properties were analyzed at harvest and after 28 days of cold storage and 4 days of shelf life. GA3 and BA application changed the fruit morphological traits, improved skin strength, and increased carotenoid, anthocyanin and sucrose content while decreasing the titratable acidity at harvest. The beneficial effects of higher sucrose, anthocyanin and carotenoid levels persisted in all PGR-treated fruits after cold storage and shelf life. GA3-treated fruits had firmer flesh, stronger skin and higher total soluble solids (TSS) content, while in BA-treated plums, these effects were rootstock-dependent. The physical properties and chemical composition of plum fruit in the postharvest period suggest beneficial effects of the applied PGR treatments. Moreover, these chemical treatments might have prolonged the beneficial impact on fruit storability, nutritional profile and sensory properties. Based on our results, GA3 preharvest treatment can be included in standard cultivation practices within contemporary production systems of European plums not only to improve fruit quality at harvest but also to improve the storage potential and nutritional value, regardless of the rootstock used.

Coating Application to Extend the Shelf Life of Sweet Potatoes cv. Cilembu

Sweet potato (Ipomoea batatas L.) cv. Cilembu (Cilembu) is one of the commodities listed in Geographical Indications (IG) with number IDIG000000019. The specialty of Cilembu is that it tastes sweet like honey, making it attractive to the export market. The export market distribution process takes a relatively long time, so treatment is needed to maintain quality. Coating application is one of the efforts to slow down the process of respiration and transpiration which causes a decrease in quality. The purpose of the study was to determine the best coating application made from aloe vera flour and carrageenan in maintaining the quality of Cilembu sweet potato. The stages of the research were sample preparation, coating solution making, application of coating, and observation for 30 days of shelf life. The concentration of coating solution was aloe vera (AL) 1% and 2%, and carrageenan (K) 0.01% and 0.02%. The best coating formulation was selected based on quality parameters of Cilembu, namely browning index, weight loss, total dissolved solids and hardness. Based on the value of these parameters, AL2K2 coating (combination of 2% aloe vera and 0.02% carrageenan) is the best coating formulation that can minimize quality loss after 30 days of room temperature storage (27°C-30°C). The application of AL2K2 coating can maintain a browning index of 2.3, weight loss of 7.82%, total dissolved solids 15.2 °brix, and hardness of 5.59 kgf while the control (without treatment) value of these quality parameters are 4.30, 9.59%, 14.4 °brik, and 5.52 kgf for each of these parameters

I AD values of apricot (Prunus armeniaca L.) at harvest in relation to fruit quality and sensory properties during cold storage and shelf life

ABSTRACT DA-meter enables quick and non-invasive determination of fruit ripeness in different types of fruit, including apricots. In order to examine the postharvest physiology of apricots, fruits were divided into five I AD categories (0.00; 0.01−0.40; 0.41−0.80; 0.81−1.20; and >1.20) and were analyzed in terms of the physicochemical and sensory properties at harvest, after 21 days of cold storage and after 3 days of shelf life. The specified I AD categories differed in terms of ethylene production, flesh firmness, skin colour, composition and sensory properties at harvest. After cold storage and shelf life, ethylene production and respiration patterns, sensory properties, colour and fruit composition were affected by the I AD value. Fruit assigned to the categories I AD 0.81−1.20 and I AD >1.20 categories maintained higher firmness compared with the remaining three groups. Carotenoid, phenol, fructose, sucrose, citric and succinic acid content were affected by the I AD value during storage. Apricots attained optimal properties for consumption in different postharvest periods, depending on their maturity stage. These findings suggest that I AD-based segregation can support apricot fruit management during storage and shelf life.

Redesigning a biscuit formulation to eliminate sodium metabisulfite

The investigation aimed to redesign the formulation with no trace of sodium metabisulfite (SMBS), sustained product quality, safety, and extended shelf life. The effects of optimized combination of 180 ml papain, 7 g ascorbic acid, and 780 s mixing time on dough rheology and physical, biochemical, sensory properties of redesigned biscuits were researched. Structural analysis of gluten network verified the potential of the above-mentioned combination of SMBS substituents. This formulation had promising results of every aspect (vide supra) of biscuits with 8.50 average sensory scores which was further validated by fuzzy logic analysis. Redesigning exhibited safe limit of acrylamide content (0.23 mg/kg) with a lead of 300 days in shelf life to be “best shelf-stable” by eliminating soapy odor and color variation of biscuits with time. The electronic nose analyses coupled with principal component analysis successfully validated the shelf life of biscuits by recognizing the soapy odor of the same using screened sensors (TGS 2620, TGS 2600). Novelty impact statement In the industry, sodium metabisulfite (SMBS) offers drastic effects on health as well as quality of the product with time in contrast to its potential functional benefits. This study aimed to replace SMBS completely with appropriate substituents which mimic the functions of SMBS in biscuit formulation, sustain its sensorial acceptability and also aimed to explore the usage of SMBS substituents for the enhancement of shelf life with assurance of quality, safety, and industrial benefits related to the products. Moreover, this study also provides a rapid, precise, cost-effective, state-of-the-art, and non-invasive method by introducing electronic nose with screened metal oxide sensors which assess the odor of these redesigned biscuits for assisting the aim of the investigation as well as for meeting the reliability of the consumers.

Simulated transit vibration effects on the postharvest quality of persimmon during storage

The mechanical damage of fresh fruit due to postharvest transport vibration is a major problem in the agricultural industry that dramatically impacts product quality. The quality loss is mainly affected by vibration frequency. In this study, the effects of different simulated vibration frequencies (5, 10, and 15 Hz) on the postharvest quality of persimmons were assessed. Changes in physical properties (weight, geometric mean diameter, surface area and volume), mechanical properties (firmness and rupture force) and chemical properties (pH and total soluble solids) were measured during 4 days of shelf life at 20 °C. Transport vibration contributed to the deterioration of the quality of persimmons during storage, resulting in increased weight loss, pH and total soluble solids, and decreased geometric mean diameter, surface area, volume, firmness and rupture force. After 4 days of shelf life, persimmons subjected to vibration frequencies of 5, 10 and 15 Hz exhibited weight losses of 2.12 %, 2.63 % and 3.26 %, respectively, in comparison to 0.83% on the samples without vibration stress (control). The average values of firmness for the control samples decreased 18%, while these changes for samples subjected to vibration frequencies of 5, 10 and 15 Hz, were 34 %, 56 % and 52 %, respectively. The corresponding mean values for the rupture force were 11 %, 19 %, 38 % and 31 %, respectively. The average pH value of the control samples was 5.72 on the first day, which was increased to 6.16 on the fourth day of storage, at a rate of about 7 %, while the increasing rates for the vibration stressed samples with frequencies of 5, 10 and 15 Hz were about 21 %, 33% and 30 %, respectively. Vibration with a frequency of 10 Hz caused the most severe mechanical damage in persimmons.

Volatile compositions of strawberry fruit during shelf life using pre and postharvest hexanal treatment

Changes in volatile compositions were determined in Rubygem strawberry variety related to pre and postharvest hexanal application during shelf life. For this concern, Rubygem variety was treated with hexanal vapor and spray applications which were, doses (0%, 0.01%, 0.02%) pre and postharvest after hexanal applications strawberry fruits were stored at 2°C and RH 90% conditions. Effects of hexanal spray and vapor applications of strawberry fruit volatile profiles were analyzed with HS-SPME/GC–MS techniques. Differences among treatments were identified in volatile compositions at 3 days intervals during 15 days of shelf life. The results showed that, hexanal application type and concentration effected the percentage of volatile composition of esters, ketones, terpens, alcohols, acids, aldehydes, and others during shelf life. The hexanal application form and concentration were effected the amount and composition of volatiles of Rubygem strawberry fruit. As a result, hexanal spray application has important effects on ester percentage, however, hexanal vapor treatment increased the alcohols percentage of strawberries at the end of shelf life. Practical applications Application of organic substances of hexanal pre and postharvest season has been successfully used due to their environmentally friendly effects. Hexanal is volatile gases, organic aldehydes which are the source of plant extract and used as food additives. There are many research on hexanal application to prevent microbial growth after harvest. In the present study, hexanal spray and vapor applications were used to determined the volatiles profile strawberries fruit during shelf life.

The Quality Analysis and Deterioration Mechanism of Liquid Egg White during Storage

The quality of liquid egg white (LEW) during storage is critical for the development of the egg industry. In order to effectively control its storage quality, the effects of packaging materials and storage conditions on the quality of LEW were investigated. High-throughput sequencing (HTS) was applied to explore changes in bacterial population proportions and microflora in the spoilage of LEW. The shelf life of LEW packaged with glass (LEW-PG), plastic (LEW-PP), and tinplate (LEW-PT) was preliminarily determined to be 8, 5, and 7 days, respectively. LEW-PG possessed superior sensory scores (65) and L values (87.5), and a lower growth rate of total volatile basic nitrogen (TVB-N) content among the three samples on the last day of shelf life, and was chosen for further study. During 24 days of storage, the sensory scores of the LEW-PG in 10 °C and 4 °C groups decreased by 32.7% and 25.7%, respectively. There was no significant difference in foaming properties of LEW-PG between the 10 °C and 4 °C groups (p > 0.05). HTS analysis showed that the abundance of species composition in the 10 °C samples was higher than that in the 4 °C samples, though the latter possessed a higher community diversity. At the genus level, the dominant bacteria in the 10 °C group were Pseudomonas (21.79%), others (19.21%), and Escherichia (11.21%), while others (37.5%), Escherichia (30.40%), and Bifidobacterium (17.72%) were highly abundant in the 4 °C samples. It is hoped that this study could provide theoretical support for quality control of LEW during storage.

Development of ginger, turmeric oleoresins and pomegranate peel extracts incorporated pasteurized milk with pharmacologically important active compounds

The purpose of this study is to develop pasteurized milk incorporated with pharmacologically important active compounds in ginger (Zingiber officinale), turmeric (Zingiber officinale) and pomegranate (Punica granatum) peel. The aim was to enhance human immunity with acceptable sensory properties in the final product and evaluating proximate composition, physiochemical properties and microbial acceptance. Plant extracts were incorporated to enhance immune responses while providing several health benefits due to their active compounds. To identify active compounds of plant extracts GCMS analysis was conducted and several pharmacological important compounds were identified. The sample was subjected to sensory evaluation by 5 point hedonic scale to analyze the sensory properties to select the best formulation for the product. The formulation of 300 ppm of ginger, 100 ppm of turmeric and 300 ppm of pomegranate was found to be significantly best at 5% level of significance. Proximate composition of fortified and normal milk was measured in first day of shelf life. Proximate composition of fortified sample includes moisture% (87.41 ± 0.45), Fat% (3.73 ± 0.06), Protein% (3.06 ± 0.44), carbohydrate% (4.73 ± 0.06) and ash% (0.69 ± 0.03) content. There was no significant difference (p > 0.05) between standard pasteurized milk and newly developed milk sample with respect to proximate composition except for ash content. When considering physiochemical properties of the fortified final product; antioxidant activity (40.615 ± 0.447) and gallic acid equivalent total phenolic content (0.532 ± 0.004) was significantly higher (p < 0.05). Antimicrobial properties of plant extracts against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans were checked using agar well diffusion method. All 3 extracts have shown inhibition towards selected pathogenic bacteria and fungi. Final product possesses antimicrobial properties, high antioxidant activity and total phenolic content. Thereby, it can be concluded this product has a considerably improved medicinal value than normal milk as it was incorporated with ginger, turmeric and pomegranate peel extracts.

Effects of ripening stage and postharvest treatment on apricot ( Prunus armeniaca L.) cv. NS4 delivered to the consumers

Fully ripe apricots (Iad < 0.1) were stored during 21 days at low temperature (1 ± 1°C) under different CO2/packaging treatments: non treated, stored non-packed after 24 hr in 100% CO2, stored packed in 100% CO2 and stored in commercial micro perforations (MAP) bags in which CO2 concentration reached up to 7%. Obtained results were compared with fruits harvested in commercial ripening stage (Iad 0.4–0.8), cold-stored for 21 days and subjected to 3 and 8 days of shelf life. Lower ethylene production and respiration rate, higher total soluble solids and sucrose and lower citric acid content characterizing fully ripe fruits in comparison to fruits harvested as commercially ripe even after prolonged postharvest ripening were noted as advantages of fully ripe fruits. Packaging in MAP bags seems to be the promising alternative for marketing of fresh apricots. Browning is the main quality deficiency which deserves further attention. Novelty impact statement Possibilities for distribution of apricots harvested as fully ripe fruit through the cold chain as alternative to distribution of commercially ripe apricots was investigated. Lower ethylene production and respiration rate, higher total soluble solids and sucrose and lower citric acid content were noted as advantages of fully ripe fruits delivered to consumers. Tissue browning, which depends on CO2 concentration in apricot packaging units, was noted as the main problem limiting possibilities for distribution of fully ripe apricots.

Astaxanthin improves the shelf-life of tilapia fillets stored under refrigeration.

Astaxanthin, classified as a xanthophyll, has antioxidant properties about 500 times greater than α-tocopherols and ten times greater than β-carotenes. Based on the antioxidant activity of this carotenoid, this study aimed to evaluate the shelf-life of tilapia fillets (Oreochromis niloticus) fed with astaxanthin, by determining the microbiological quality (colimetry, counts of mesophilic and psychrotrophic microorganisms), physicochemical analyses (colorimetry, pH, thiobarbituric acid reactive substances (TBARS)) and sensory analysis. Tilapia supplemented with astaxanthin presented a reduction in the counts of microorganisms (mesophiles and psychrotrophics) and lower lipid oxidation index (TBARS), when compared to fillets of control fish. Colorimetric changes of fillet degradation were observed, associated with increased pH during storage, as well as loss of brightness and texture in addition to worsening of appearance and odor. These deteriorating changes were minimized using astaxanthin. Our results demonstrate the beneficial performance of astaxanthin in the shelf-life of tilapia fillets stored under refrigeration. Therefore, dietary supplementation with astaxanthin (100 and 200 mg kg-1 of feed) improves the microbiological and physicochemical quality of tilapia fillets during 50 days of shelf-life. © 2022 Society of Chemical Industry.

Da li primena naftenskih kiselina u ranoj fazi razvoja voća ima produženi efekat na skladišnu sposobnost i rok trajanja plodova kajsije?

In this experiment, the effects of the application of naphthenic acids (NAs) on apricots in the early fruit development phases on fruit morphological properties, composition and postharvest properties were investigated. Two concentrations of NAs (1 mg/L and 3 mg/L) were applied at two development stages in the apricot cultivar NS-4. The application of NAs at the beginning of the petal fall development phase resulted in the reduction of fruit dimensions at harvest while the application 7 days later increased fruit dimensions. Although there were no significant differences in the most investigated characteristics between fruits treated with NAs and untreated control at harvest or in the postharvest period during 20 days of cold storage (1 ± 1 °C, RD 80%) and particularly after 3 days of shelf life at room temperature. However, compared to the untreated control, apricots treated with NAs were characterized by higher total soluble solids content accompanied by higher fructose content, and lower titratable acidity accompanied by higher succinic acid content. Apricots treated with NAs showed trends towards improved sensory properties: sweeter and less sour taste, with more expressed apricot aroma accompanied with decreased gumminess and crispiness and more intensive tissue breakdown, but without expressed notes of inappropriate taste.

Da li primena naftenskih kiselina u ranoj fazi razvoja voća ima produženi efekat na skladišnu sposobnost i rok trajanja plodova kajsije?

In this experiment, the effects of the application of naphthenic acids (NAs) on apricots in the early fruit development phases on fruit morphological properties, composition and postharvest properties were investigated. Two concentrations of NAs (1 mg/L and 3 mg/L) were applied at two development stages in the apricot cultivar NS-4. The application of NAs at the beginning of the petal fall development phase resulted in the reduction of fruit dimensions at harvest while the application 7 days later increased fruit dimensions. Although there were no significant differences in the most investigated characteristics between fruits treated with NAs and untreated control at harvest or in the postharvest period during 20 days of cold storage (1 ± 1 °C, RD 80%) and particularly after 3 days of shelf life at room temperature. However, compared to the untreated control, apricots treated with NAs were characterized by higher total soluble solids content accompanied by higher fructose content, and lower titratable acidity accompanied by higher succinic acid content. Apricots treated with NAs showed trends towards improved sensory properties: sweeter and less sour taste, with more expressed apricot aroma accompanied with decreased gumminess and crispiness and more intensive tissue breakdown, but without expressed notes of inappropriate taste.

Development of a Monte Carlo simulation model to predict pasteurized fluid milk spoilage due to post-pasteurization contamination with gram-negative bacteria

Psychrotolerant gram-negative bacteria introduced as post-pasteurization contamination (PPC) are a major cause of spoilage and reduced shelf life of high-temperature, short-time pasteurized fluid milk. To provide improved tools to (1) predict pasteurized fluid milk shelf life as influenced by PPC and (2) assess the effectiveness of different potential interventions that could reduce spoilage due to PPC, we developed a Monte Carlo simulation model that predicts fluid milk spoilage due to psychrotolerant gram-negative bacteria introduced as PPC. As a first step, 17 gram-negative bacterial isolates frequently associated with fluid milk spoilage were selected and used to generate growth data in skim milk broth at 6°C. The resulting growth parameters, frequency of isolation for the 17 different isolates, and initial concentration of bacteria in milk with PPC, were used to develop a Monte Carlo model to predict bacterial number at different days of shelf life based on storage temperature of milk. This model was then validated with data from d 7 and 10 of shelf life, collected from commercial operations. The validated model predicted that the parameters (1) maximum growth rate and (2) storage temperature had the greatest influence on the percentage of containers exceeding 20,000 cfu/mL standard plate count on d 7 and 10 (i.e., spoiling due to PPC), which indicates that accurate data on maximum growth rate and storage temperature are important for accurate predictions. In addition to allowing for prediction of fluid milk shelf life, the model allows for simulation of "what-if" scenarios, which allowed us to predict the effectiveness of different interventions to reduce overall fluid milk spoilage due to PPC through a set of proof-of-concept scenario (e.g., frequency of PPC in containers reduced from 100% to 10%; limiting distribution temperature to a maximum of 6°C). Combined with other models, such as previous models on fluid milk spoilage due to psychrotolerant spore-forming bacteria, the data and tools developed here will allow for rational, digitally enabled, fluid milk shelf life prediction and quality enhancement.

Combined effects of storage temperature variation and dynamic controlled atmosphere after long-term storage of ‘Maxi Gala’ apples

The present study aimed to evaluate the effects of temperature variation strategies during the storage period using a dynamic controlled atmosphere based on respiratory quotient (DCA-RQ) on the physicochemical qualities of ‘Maxi Gala’ apples after 9 months of storage plus 7 and 14 days at 20 °C. The apples were stored in a controlled atmosphere with ultra low oxygen (CA/ULO), CA/ULO + 1-methylcyclopropene (1–MCP) at 0.5 °C, and DCA-RQ 1.3 at three constant temperatures of [1] 0.5, [2] 2.0, and [3] 3.0 °C and four variation temperatures of [1] (0.5 +3.0), [2] (0.5 +2.0), [3] (2.0 +3.0), and [4] (0.5 +2.0 + 3.0) °C. After 9 months of storage plus 14 days at 20 °C, fruit stored in DCA-RQ, regardless of the temperature, maintained the lowest incidence of flesh breakdown and highest healthy fruit percentages in relation to conventional CA/ULO with and without 1-MCP application. However, after 7 days of shelf life, storage in CA/ULO and DCA-RQ 1.3 at 2.0 and 3.0 °C resulted in higher percentage of healthy fruit. At this evaluation time,1-MCP treatment in fruit stored under CA/ULO increased flesh breakdown and decay. Flesh firmness was higher in the fruit stored in DCA-RQ 1.3 at 0.5, 2.0, and (0.5 + 2.0) °C after 7 and 14 days at 20 °C. In conclusion, DCA-RQ 1.3 under a constant temperature of 2.0 °C or temperature increasing during storage keeps fruit with better quality than those stored in CA/ULO + 1-MCP treatment after 9 months of storage plus 7 and 14 days of shelf life.

Postharvest Quality of Two Mangosteen (Garcinia mangostana L.) Fruit Maturities Held in Ambient and CoolBot-equipped Cold Storage

Mangosteen fruit has a good demand in the global market, however, local production is beset with high postharvest losses. The effectiveness of low temperature in maintaining fruit postharvest quality is well known but costly. In this study, the effects of ambient storageand CoolBot-equipped room are determined on two maturity stages of mangosteen. The mangosteen fruit which is classified as reddish purple or dark purple was stored in either ambient conditions (26.7±0.6°C, 88.4±3.4% RH) or inside a modified cold room using CoolBot (9.9±1.8°C, 77.8±10.7% RH) and the quality was evaluated weekly. Mangosteen at both maturity stages had at least 8.5 days of shelf life under ambient conditions and 29.8 days under CoolBot storage. Peel color was maintained for less than four days after storage in ambientm while 35 days in room with CoolBot. There was a higher total soluble solids (TSS) content in dark purple fruit in both storage conditions. Pericarp hardening of the fruit was observed starting at 7 and 28 days in ambient and CoolBot storage, respectively. Fruit stored in the CoolBot-equipped room had better visual and calyx quality, lower weight loss, higher TSS, and delayed peel color change. Chilling injury which manifested as inner pericarp browning at 35 days did not vary between the two fruit maturities in cold storage. Storage of reddish purple mangosteen fruit using CoolBot maintained the fruit quality until 28 days.

Imidazole derivative with an intramolecular hydrogen bond as thermal latent curing accelerator for epoxy/phenolic resins

AbstractOne‐component epoxy systems with long shelf life during storage or transportation, while high curing reactivity during molding as well as satisfactory mechanical and thermal performances after curing, are extremely essential for industrial application. Herein, we used salicylaldehyde and o‐phenylenediamine to synthesize 2‐(2′‐hydroxyphenyl)‐1H‐benzimidazole (HPBI), an imidazole derivative with an intramolecular hydrogen bond between the phenolic hydroxyl group and the pyridine‐type nitrogen atom of imidazole ring, and further employed HPBI as a thermal latent curing accelerator for epoxy/phenolic resins. The intramolecular hydrogen bond endowed HPBI with inert activity toward resins at room temperature, making the one‐component resin system a long‐term storage stability (21 days of shelf life at 30°C). Once rising the temperature to a high degree, a rather high activity of HPBI to accelerate the curing process of epoxy/phenolic resins. It was attributed to the effective release of high activity of the pyridine‐type nitrogen by breaking the intramolecular hydrogen bond at high temperature. In addition, the resulted thermosets from HPBI also possessed the comparable Tg (&gt;130°C, determined by DMA) and thermostability (Td‐5% &gt; 380°C) with that from common curing accelerators. Therefore, HPBI was proved to be a promising thermal latent curing accelerator applied in electronic packaging field.

The synergistic effects of aloe vera gel and modified atmosphere packaging on the quality of strawberry fruit

The aim of this study was to evaluate modified atmospheric packaging containing 500 ppm cinnamon essential oil, aloe vera concentrated gel (1:3 with distilled water), calcium lactate, and ascorbic acid on the shelf life of strawberry. Acidity, antioxidant activity, soluble solids, phenolic compound, anthocyanin content, vitamin C content, weight loss, firmness, color, gas composition as well as microbial quality were determined during 15 days of shelf life. According to the results, the antioxidant activity was significantly higher in samples stored in aloe vera packaging (89 ± 5.43%); besides, a higher percentage of anthocyanin content (66.57 ± 20.55 mg/L) and vitamin C values were proved in modified atmospheric aloevera packaging. Also, aloe vera packaging could reduce decay by significantly suppressing the total aerobic mesophilic bacteria, yeast, and mold growth (p < .05). In summary, aloe vera gel, ascorbic acid, calcium lactate, cinnamon EO, and modified atmosphere packaging could significantly prevent the quality loss of strawberries and extend its shelf life. Novelty impact statement A combination of Aloe Vera gel coating ascorbic acid, calcium lactate, cinnamon essential oil and modified atmosphere packaging preserved the postharvest quality of strawberry fruit stored at 4°C for 15 days. The efficacy of Aloe Vera gel coating enriched with ascorbic acid, calcium lactate, and cinnamon essential oil, packed in the modified atmosphere on the protection of phenolic, and antioxidant content was evaluated. The addition of cinnamon essential oil to coating reduced the microbial load of strawberry fruit.

Composition Changes in Lycium ruthenicum Fruit Dried by Different Methods.

The fruit of Lycium ruthenicum (LRF), known as black wolfberry, is a medicinal and edible fruit. The fresh LRF is perishable and has only about 3 days of shelf life. Drying could prolong the shelf life of LRF. However, it could imply physical changes and chemical modification. This study evaluated the effect of sun drying (SD), hot air drying (HD), and freeze drying (FD) on the appearance characteristics, moisture content, bioactive compounds, amino acid composition, and antioxidant activity of LRF. The results showed that LRF dried by FD was round, expansive, fragile, and maintained the largest amount of appearance traits among the three drying methods. Drying methods had a significant effect on phytochemical content and antioxidant activity of LRF (P < 0.05). Principal component analysis (PCA) showed that procyanidin content (PAC), asparagine (Asn), total phenolic content (TPC), total anthocyanin content (TAC), and moisture content were the main sources of the difference in LRF dried by different methods. The characteristic of LRF in FD was low moisture content, and high TPC, Asn, PAC, and TAC. Sun drying was opposite to FD. Hot air drying was high TPC and low TAC content. The quality of LRF was in the order of FD > HD > SD based on comprehensive evaluation of the phytochemical component content and antioxidant capacity. Additionally, the water temperature and soaking time had different antioxidant activity effect on LRF dried by different methods. These findings will provide useful information for production and utilization of LRF.

Growth potential of Listeria monocytogenes in veal tartare.

In the present study the growth potential of Listeria monocytogenes in veal tartare was evaluated. A challenge test was performed on three tartare batches at 8°C, aiming to evaluate the growth potential of the pathogen. The data indicated the absence of a significant growth (δ<0.5 log cfu/g) during the entire period. When considering intermediate sampling times, an increase of 0.56 log cfu/g was detected after five days of storage in one of the batches. Microflora of veal tartare was dominated by lactic acid bacteria, that increased gradually during the trial, reaching counts up to 7 Log CFU/g in two of the three batches considered. Spoilage bacteria were present (especially Pseudomonas spp., yeasts and Enterobacteriaceae) but in very low counts and with a limited increase during the period considered. Finally, daily maximum tolerable L. monocytogenes counts were calculated to highlight the maximum acceptable load to avoid the overcoming of the legal limit of 100 CFU/g: a total increase of 0.95 log cfu/g in 12 days of shelf-life was estimated, obtaining a “safety initial concentration” at t0 of 10 CFU/g of the pathogen.

Salicylic acid and nutrient immersion to maintain apple quality and bioactive compounds in postharvest

The world production of apples in the 2019 cycle reached 7´620,288 tonnes. For marketing purposes and to supply the demand, apple fruits need to be stored for different periods under refrigerated conditions. However, in the market, the shelf life of the fruit is short, the quality decreases in postharvest due to the dynamic changes of its physicochemical properties, which cannot be stopped, but can be slowed down to improve its shelf life. Postharvest treatments by immersing apple fruit in salicylic acid (SA) and nutrients are an innovative technological alternative to maintain their quality. In this study, 5 concentrations were tested for the immersion of apple fruits cv ‘Golden Delicious’, using a 56 factorial arrangement delimited to 25 treatments, using the Taguchi L25 structure: SA 0 - 1.440 mM, potassium (K) 0 - 2.250, calcium (Ca) 0 - 31.500 mM, cobalt (Co) 0 - 0.180 mM, molybdenum (Mo) 0 - 0.0900 mM and magnesium (Mg) 0 - 0.0900 mM. The study was conducted in the municipality of Cuauhtémoc, Chihuahua, Mexico. After 7 months of storage and 13 days of shelf life, the combination of K, Ca, SA and Co with the appropriate concentration values can maintain the quality variables and bioactive compounds at the desired optimum. It is concluded that the quality variables; firmness, juice percentage, juice density, titratable acidity and total soluble solids and the bioactive compounds; total phenols and antioxidant capacity can be maintained at the desired optimum.