Shelf-life Of Strawberry Fruit Research Articles

The Effect of Putrescine and Modified Atmosphere Packaging (MAP) Treatments on Fruit Quality Characteristics of Strawberry (Kabarla cultivar) During Cold Storage

Strawberry is a fruit species that must be harvested at full ripening and at the same time has an extremely short shelf life and deteriorates rapidly. Therefore, it is important to extend the shelf life after harvest. In this study, putrescine and modified atmosphere packaging (MAP) were applied during cold storage in order to maintain the quality and extend the shelf life of strawberry fruit. The commercial ripening fruit were treated with 1 mM putrescine and stored in MAP for 20 days. The quality characteristics such as weight loss, soluble solids content, titratable acidity, fruit color, organic acid and phenolic content were measured and analyzed on days 4, 8, 12, 16 and 20 of storage. At the end of 20 days of the cold storage, the highest weight loss was in control treatment (%). The decrease in soluble solids content (SSC) and titratable acidity (TA) values during cold storage was slowed down by MAP and putrescine treatments. Organic acids and phenolic compounds were significantly affected by storage time and MAP and putrescine treatments. After 20 days of the cold storage, citric acid (748.91 mg 100 g -1) and malic acid (258.34 mg 100 g-1), which were determined as basic organic acids, were highest in putrescine treatment. Shikimic acid (0.77 mg 100 g-1) and isocitric acid (112.58 mg 100 g-1) as phenolic compounds were highest in MAP and MAP+ putrescine treatments, respectively. These results releaved that the application of putrescine and modified atmosphere packaging (MAP) during cold storage significantly extends the market life of strawberries by preserving their quality attributes.

Foliar spraying of boron prolongs preservation period of strawberry fruits by altering boron form and boron distribution in cell.

Boron (B), an essential micronutrient for fruit development, also plays a crucial role in maintaining the shelf life of strawberries (Fragaria ananassa Duch.) by affecting cell wall structure and components. We investigated the distribution pattern of B within cells and cell walls in strawberry fruits under different B levels and revealed the relationship between the B distribution in cell walls and fruit firmness after harvesting. Foliar spraying of 0.1% H3BO3 promoted the growth of strawberry seedlings and improved fruit yield and flesh firmness by 45.7% and 25.6%. During the fruit softening and decay process, the content of bound B and cell wall-B decreased while more B was allocated to the protoplast and apoplast. The changes in B distribution in cells were attributed to cell damage during fruit decay, and B extended the freshness period of the fruits by alleviating the decrease of B distribution in cell walls. After leaving the fruits at room temperature for 10 h, the B content in different cell wall components significantly decreased, while foliar spraying of B alleviated the reduction of B content in covalently bound pectin (CBP), cellulose, and hemicellulose. Meanwhile, B spraying on fruit decreased the activity of cell wall degradation enzymes, including polygalacturonase (PG) and pectin lyase (PL), by 20.2% and 38.1%, while enhancing the demethylation of pectin by increasing pectin methylesterase (PME) activity from 21.6 U/g to 25.7 U/g. Thus, foliar spraying of 0.1% H3BO3 enhances the cross-linking of B with cell wall components and maintains cell wall structure, thereby prolonging the shelf life of strawberry fruits.

Efficacy of nano-zinc oxide and iron oxide formulations on shelf life of strawberry

The research investigates the transformative impact of nano-zinc oxide and iron oxide formulations on prolonging the shelf life of strawberries. A total of 16 distinct treatments were applied through foliar application, and a nano-zinc oxide (ZnO) and iron oxide (FeO) formulations were administered. Each square meter received 42 ml of the solution in triplicate, ensuring a comprehensive exploration of the formulations' impact on shelf-life enhancement. Notably, the combined application of ZnO and FeO NPs at 150 mg/l, specifically T15 (Z3F3), exhibited superior effectiveness in preserving the crop. T11 (Z2F2), featuring 100 mg/l ZnO and 100 mg/l FeO, closely trailed T15, showcasing significant improvements in parameters such as ascorbic acid content (49.66 mg/100g), and anthocyanin content (39.82 mg/l), etc. at nine days after harvesting. Besides this, TSS (7.25 obrix) in T14 and acidity (0.65%) in T5 and T9 at nine days intervals. These findings advancing the strawberry preservation methods in the agriculture and food industries and establishes the superiority of simultaneous applications of nano-formulations in T15 (150 mg/l ZnO + 150 mg/l FeO) and T11 (100 mg/l ZnO + 100 mg/l FeO). These formulations emerge as optimal solutions for extending the shelf life of strawberry fruits, particularly the Cv. Winter Dawn under Punjab Region, India, and could implement in similar climatic condition around world.

Investigating the effect of acoustic waves on spoilage fungal growth and shelf life of strawberry fruit

The effects of acoustic waves on growth inhibition of food spoilage fungi (Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus and Botrytis cinerea) on the medium and strawberry surfaces were investigated. Firstly, single-frequency sound waves (250, 500, 1000, 2000, 4000, 8000, 12,000 and 16,000 Hz) were induced on inoculated medium with fungi spores for 24 h and growth diameter of each mold was evaluated during the incubation period. In the second stage, the sound waves with two frequencies of 250 Hz and 16,000 Hz were induced on inoculated strawberries with fungi spores at 5 °C for different times (2, 4, 6, 8 and 10 days). The results from the first stage indicated that the sound waves inhibited the growth of A. niger (20.02%) at 250 Hz and B. cinerea (4/64%) at 4000 Hz on potato dextrose agar (PDA) surface. Also, comparison of the growth diameter of some species of Aspergillus revealed various responses in presence of 250 Hz frequency. In the second stage, applying a frequency of 250 Hz over a period of 10 days proved to be more effective in inhibiting the growth of A. niger and B. cinerea on strawberries inoculated with fungal spores. Consequently, the shelf lives of the strawberries significantly increased to 26 days and 18 days, respectively, under this treatment. Based on the findings, it is concluded that sounding with acoustic waves can be used as a green and cheap technology along with other technologies to improve food safety.

Pre-harvest treatments: A different insight into preservation of strawberries

Strawberry is one of the most favored consumed fresh fruits worldwide. However, the major constraint limiting future sustainable production and sales of strawberries is post-harvest decay. Thus, taking a deep look into the effective preservation measures including pre- and post-harvest techniques to retain freshness and inhibit the pathological spoilage of strawberries in the supply chain is of great significance and necessity. At present, relying solely on post-harvest technology is not enough to fix the aim of strawberry fruit preservation and longer shelf life. On the contrary, pre-harvest treatments could be extend shelf life of strawberry fruit and adapt to the diverse post-harvest environments. This review give the latest pre-harvest treatments, their effects on post-harvest quality and storability of strawberries, and develop the expectation of strawberries pre-harvest methods applicated in the future.

Quality and shelf life of strawberry fruit as affected by edible coating by moringa leaf extract, aloe vera gel, oxalic acid, and ascorbic acid

ABSTRACT In the current study, the most effective concentrations of moringa leaf extract (MLE), aloe vera gel (AV gel), ascorbic acid (1 mM) and oxalic acid (5 mM) were used. Physically mature fruits harvested from a commercial orchard were dipped in aqueous solutions of different edible coatings and kept at ambient conditions (25±2ºC & 55-60% RH) for evaluation of the quality and enzymatic parameters on daily basis till marketability. Current results revealed that 5 mM ascorbic acid treatment resulted in 57% reduced fruit weight loss; while 20% AV gel coating increased firmness by 60% over a 5-day ambient storage period. Application 6% MLE exhibited 50.7% and 49.7% reduced respiration rate and ethylene production respectively. Fruit biochemical quality parameters were also improved with the lowest accumulation of total soluble solids as a result of slow respiration, higher titratable acidity, ascorbic acid contents, carotenoids and anthocyanin contents in all treated fruit. While, total phenolic contents and total antioxidants along with superoxide dismutase, catalase, peroxidase, and anthocyanins were higher in ascorbic acid treated fruits. The activity of poly phenol oxidase enzyme was lowest in fruits treated with 5 mM ascorbic acid solution. Conclusively, the application of different edible coatings was proved to be beneficial as numerous fruit biochemical and antioxidative attributes were improved by ascorbic acid treatment; furthermore, MLE, AV gel and oxalic acid treatments were also helpful in maintaining fruit quality of strawberry fruits over a 5-days ambient storage period.

Effect of Different Levels of Carbon Dioxide Concentrations on Qualitative Traits of Strawberry (Fragaria × Ananassa) during Storage var. Winter Dawn

The present investigation the effect of different levels of carbon dioxide concentration on qualitative traits of strawberry during storage was studied. Strawberry (Fragaria × ananassa) were stored at ambient temperature for 5 days and controlled temperature at 5oC for 14 days in eight different atmospheres: air, 5% CO2, 10% CO2, 15% CO2, 20% CO2, 25% CO2, 30% CO2, 35% CO2. Changes in several parameters were evaluated. Atmosphere with high carbon dioxide were the most effective in preventing the fungal growth and enhancing strawberry firmness. However, other quality parameters such as color, titrable acidity, ascorbic acid, TSS, pH, aroma were only mildly affected by superatmospheric CO2 levels. The result showed that atmosphere with treatment 35% CO2 proved as the most effective one to control the weight loss, firmness, and to minimized the fruit decay. In conclusion, strawberries stored under superatmospheric carbon dioxide conditions maintained the fungal growth, firmness, weight loss and increase the shelf life as compared to air stored. In future, these experimental results may prove very useful for increasing the shelf life of strawberry fruits for certain period in better quality.

Effect of Pre-Harvest Melatonin and Salicylic acid treatments on Decay, Maintaining Quality and Extend the Shelf life of Strawberry fruits

Effect of Pre-Harvest Melatonin and Salicylic acid treatments on Decay, Maintaining Quality and Extend the Shelf life of Strawberry fruits

The Effect of Post-Harvest Calcium Chloride Applications on the Shelf Life Quality of Strawberry

In the study; fruit skin color parameters, fruit flesh firmness and total soluable solid (TSS) ratios, as well as total acidity, total phenolic substance, total monomeric anth°Cyanin amounts and total antioxidant capacity were determined. After the fruits were harvested, they were immersed in three different doses (0-2-4%) of calcium chloride (CaCl2) solution for 5 minutes. The fruits removed from the solution were kept to dry. The fruits were stored for 14 days in a cold store with a temperature of 1-2°C and a relative humidity of 90±5%. Before the storage and on the 7th and 14th days of storage, the fruits samples were taken and kept on the shelves in the rooms with a temperature of 21±1°C and a relative humidity of 60±5%for 3 days. Measurements and analyses of fruit quality parameters were made in the samples taken from the fruits that were kept on the shelf for three days. As a result of the study, it was determined that 4%CaCl2 application was effective in maintaining fruit flesh firmness. In fruits kept on the shelf for 3 days after 14 days of storage, SSC of 4%CaCl2 treatment was found to be higher than the control treatment. Compared to the control, 4%CaCl2 caused a significant increase in the total phenol content. The highest total monomeric anth°Cyanin content and total antioxidant capacity was determined in the control treatment. While there were no significant changes in L* values between treatments, a* and b* values were found to be higher in 2%CaCl2 treatment. In the light of the data obtained, it was concluded that 4%CaCl2 application had a positive effect on the shelf life of strawberry fruits.

Fabrication of the antimicrobial sachet by encapsulation of peppermint essential oil in active packaging of strawberry fruit

AbstractThe anti‐microbial property‐based packaging system is able to destroy and eliminate the contaminants and pathogenic microorganisms, which spoil the food. In this study, sachets were prepared by an active packaging system using starch‐based microcellular foam loaded with peppermint essential oil (SMF‐PEO). The produced SMF was used to make sachets loaded with PEO and then placed on the upper part of the strawberry package. Qualitative and biochemical traits of the strawberry fruits, such as weight loss percentage, vitamin C, phenolic substances, antioxidant capacity, anthocyanin, malondialdehyde, hydrogen peroxide content, microbial load, and antioxidant enzymes activity, were evaluated. Results of the gas chromatography confirmed EO release until the end of the fourth day of the fruit storage. Fourier‐transform infrared spectroscopy spectra showed the porosity of the SMF and the loading of PEO in its pores. Total phenol and antioxidant activity decreased during storage. At the end of storage, the most total antioxidant activity (29.04 iron II mol g−1) was found in packaged fruits with sachet, whereas the most anthocyanin (896 mg kg−1) was found in control. At the end of the storage period, the treated fruits showed a greater catalase (1660 U kg−1) and phenylalanine ammonia‐lyase (1626.6 U kg−1) activity. Packaged fruits with sachet had lower microbial load, total mesophilic bacteria in control and treated samples was 3.7 and 1.7 Log CFU g−1 in end during storage. At the end of storage, the total yeast + mold in treated and control fruits was 1.3 and 1.57 Log CFU g−1, respectively.Practical applicationsThe sachets loaded with PEO increased activity of enzymes and the decreased amount of malondialdehyde have a positive effect on increasing the shelf life of strawberry fruits and are efficient enough to reduce microbial load. Due to the inexpensiveness and degradability of starch, SMF is a suitable system for PEO loading.

Preservation of strawberry fruit with an Aloe vera gel and basil ( Ocimum basilicum ) essential oil coating at ambient temperature

Strawberry deterioration accelerates after harvesting when the fruit are exposed at ambient temperature. Therefore, it is imperative to utilize efficient methods to mitigate the deterioration of fruit at ambient temperature. In the current study, harvested strawberries were coated with Aloe vera gel either alone or mixed with essential oil from basil plant. Coated strawberries were stored at ambient temperature (20°C) for 7 days and successfully retained their postharvest quality during storage. Scanning electron microscopy was used to examine the fracture morphology of coated and uncoated fruits. Application of coatings, specially the combination of Aloe vera with basil oil, reduced weight loss, respiration rate, degradation of vitamin C, and color change. Additionally, fungal growth was intensively prevented at room temperature. Finally, sensory analyses revealed positive results for the coatings on visual aspect. The results demonstrated that application of Aloe vera–basil oil complex coating is an effective method to preserve the postharvest quality and extend shelf life of strawberry fruit at room temperature. Novelty impact statement Combination of Aloe vera gel coating and basil oil preserved postharvest quality of strawberry fruit at ambient temperature. Aloe vera gel coating enriched with basil oil reduced fungal growth in in vitro and in vivo conditions at ambient temperature. Addition of basil oil to Aloe vera gel coating improved the efficacy of treatment at ambient temperature.

High-CO2 Treatment Prolongs the Postharvest Shelf Life of Strawberry Fruits by Reducing Decay and Cell Wall Degradation

Improved methods are needed to extend the shelf life of strawberry fruits. The objective of this study was to determine the postharvest physiological mechanism of high-CO2 treatment in strawberries. Harvested strawberries were stored at 10 °C after 3 h of exposure to a treatment with 30% CO2 or air. Pectin and gene expression levels related to cell wall degradation were measured to assess the high-CO2 effects on the cell wall and lipid metabolism. Strawberries subjected to high-CO2 treatment presented higher pectin content and firmness and lower decay than those of control fruits. Genes encoding cell wall-degrading enzymes (pectin methylesterase, polygalacturonase, and pectate lyase) were downregulated after high-CO2 treatment. High-CO2 induced the expression of oligogalacturonides, thereby conferring defense against Botrytis cinerea in strawberry fruits, and lowering the decay incidence at seven days after its inoculation. Our findings suggest that high-CO2 treatment can maintain strawberry quality by reducing decay and cell wall degradation.

Post-Harvest Enhancing and Botrytis cinerea Control of Strawberry Fruits Using Low Cost and Eco-Friendly Natural Oils

This work investigates an experimental study for using low-cost and eco-friendly oils to increase the shelf life of strawberry fruit. Three natural oils were used: (i) Eucalyptus camaldulensis var obtuse, (ii) Mentha piperita green aerial parts essential oils (EOs), and (iii) Moringa oleifera seeds n-hexane fixed oil (FO). Furthermore, a mixture of EOs from E. camaldulensis var obtusa and M. piperita (1/1 v/v) was used. The treated fruits were stored at 5 °C and 90% relative humidity (RH) for 18 days. HPLC was used to analyse the changes in phenolic compounds during the storage periods. The effects of biofumigation through a slow-release diffuser of EOs (E. camaldulensis var obtusa and M. piperita), or by coating with M. oleifera FO, were evaluated in terms of control of post-harvest visual and chemical quality of strawberry fruits. The post-harvest resistance of strawberry fruits to Botrytis cinerea fungal infection was also evaluated. As a result, the EO treatments significantly reduced the change in visual and chemical quality of strawberry fruit. Additionally, changes in the titratable acidity of moringa FO-coated strawberry fruits were delayed. EO treatments improved total soluble solids, total phenols, ascorbic acid, antioxidants and peroxidase. E. camaldulensis var obtusa and M. piperita (1/1 v/v) EO-vapour fruit exhibited a slower rate of deterioration, compared to other treatments in all tested, in two experiments. The lowest colour change (ΔE) was observed inthe fruit treated with E. camaldulensis var obtusa EO and M. oleifera FO. HPLC showed changes in phenolic compounds’ concentration, where p-coumaric acid, caffeic acid, gallic acid, ferulic acid and ellagic acid were mostly identified in the fruits treated with the oils. SEM examination confirmed the potential decrease in fungal growth as the fruits were treated with EOs. In conclusion, the treatment of EOs during different storage periods showed promising characterisations for strawberry fruit quality.

Effects of hydroxyethyl cellulose and sodium alginate edible coating containing asparagus waste extract on postharvest quality of strawberry fruit

Edible coatings have been used as a medium for the incorporation of functional compounds to maintain postharvest quality parameters of fruits. In this study, we explored the influence of 1.5 g/100 mL hydroxyethyl cellulose coatings (HEC1.5), 1.5 g/100 mL sodium alginate coatings (SA1.5), and the composite coatings of 1.0 g/100 mL HEC and 0.5 g/100 mL SA (HEC1.0/SA0.5) containing asparagus waste extraction on quality of strawberry fruit. The fluorescence microscope and scanning electron microscope images showed that the HEC1.0/SA0.5 coatings displayed a continuous, smooth and porous structure. The HEC1.0/SA0.5 coatings also exhibited favorable anti-fungal activity against Penicillium italicum. Furthermore, the HEC1.0/SA0.5 coatings significantly delayed color change (ΔE), reduced weight loss, and maintained total phenolic and flavonoid contents. These results indicated that the application of HEC and SA based edible coatings containing asparagus waste extract could be an effective, safe and environmentally friendly approach to maintain the quality and extend the shelf life of strawberry fruit.

Effect of Aloysia citrodora Essential Oil on Biochemicals, Antioxidant Characteristics, and Shelf Life of Strawberry Fruit during Storage.

Strawberry fruits are highly susceptible to cold burning, resulting in low storage periods at low temperatures. Plant extracts or essential oils (EOs) can potentially be used as preservatives in fruits throughout the refrigerated period. In the present study, the biochemicals, antioxidant characteristics, and shelf life of treated strawberries with Aloysia citrodora essential oil (ACEOs) were evaluated during keeping time. The treatments were produced as follows: T1, control; T2, 250 ppm ACEOs; T3, 500 ppm ACEOs; and T4, 750 ppm ACEOs. Total soluble solids (TSS), weight loss, titratable acidity (TA), antioxidant activity (DPPH assay), total phenolic (TPC), flavonoid and anthocyanin contents (TFC), and enzymes activity (peroxidase and ascorbate peroxidase) were evaluated during the refrigerated period (5 °C with relative humidity of 85–90% for 20 days). The results revealed that weight loss and TA were reduced in all treatments during storage, being that the rates were lower in samples treated with ACEOs. TPC, TFC, TSS, antioxidant, and enzymes activity were higher in treated fruits than control.

Influence of Pre-Harvest Gibberellic Acid and Post-Harvest 1-methyl Cyclopropane Treatments on Phenolic Compounds, Vitamin C and Organic Acid Contents during the Shelf Life of Strawberry Fruits.

In recent years, significant portions of the fresh fruits and vegetables produced worldwide have been decaying before reaching the consumer because of insufficient preservation after harvest. In this direction, we carried the study out to investigate the effect of gibberellic acid (GA3) and 1-methyl cyclopropane (1-MCP) applications on phenolic compounds and organic acid contents of the strawberry fruits (cv. Albion) during shelf-life. Gibberellic acid treatments, which prepared in two different concentrations (50 and 100 ppm), were performed by spraying the leaves before harvest. 1-methyl cyclopropane applied after harvest. The results of the study showed a greater decrease in organic acids (except oxalic and succinic acid) in Gibberellic acid-applied fruits during shelf-life. Citric acid was recorded as the most abundant organic acid in the control group. In phenolic compounds, gallic acid (15.22 mg 100 g−1) and ellagic acid (9.38 mg 100 g−1) were recorded as the highest phenolic compounds on the third day. 1-MCP and GA3 (50 ppm) + 1-MCP treatment reduced the breakdown of vitamin C during the shelf-life of strawberry fruits compared to the control group. As a result, phenolic compounds, vitamin C, and organic acids decreased during the shelf-life, and 1-MCP applications slowed down the breakdown of these compounds.

The Effect of Cultivation Method of Strawberry (Fragaria x ananassa Duch.) cv. Honeoye on Structure and Degradation Dynamics of Pectin during Cold Storage.

The high quality and long shelf life of strawberry fruit are largely dependent on the cultivation method. The goal of this experiment was to study the effect of different cultivation methods on molecular structure and rheological properties of pectin extracted from strawberry quality parameters during cold storage. Three methods of cultivation of strawberry cv. Honeoye were tested: organic cultivation on raised beds, organic cultivation with the flat-planted method and conventional cultivation with the flat-planted method. The nanostructure of pectin (AFM), its chemical structure (FT-IR) and rheological properties were studied. The fruits were also tested by size, dry matter, firmness, acidity and the content of soluble solids, anthocyanin, phenolics, vitamin C and galacturonic acid. Pectin isolated from organic strawberries was more rapidly degraded than conventional strawberry pectin, which limits the possibilities for their processing and use as gelling or stabilizing agents at 20 °C. The differences in fruit quality were particularly noticeable with respect to the anthocyanin content, which was significantly higher for organic strawberry. The organic fruit also had better sensory properties because of its lower acidity and higher soluble solid content (SSC). These and other results from this experiment showed that strawberries produced by organic farming methods had better biochemical properties compared to conventional fruit; however, pectin transformation undergone faster limits their further technological applications.

Effect of nanocomposite-based packaging and chitosan coating on the physical, chemical, and mechanical traits of strawberry during storage

The combined use of fruit coating with nanocomposite packaging film is a novel technique for maintaining the quality and assisting more appropriate storage conditions. In the present study, a novel nanocomposite-based packaging was prepared by blending polypropylene and polyolefin elastomer with nanoclay. Strawberry fruit (Gavita cultivar) was evaluated for determining the effect of chitosan coating, packaging with polyethylene film and clay nanocomposite film on physical, chemical, and mechanical traits. Dependent variables including chemical (pH and Brix percentage), physical (color and weight loss), mechanical properties (firmness and elasticity modulus) and independent variables including two temperature levels (including 25 and 4 °C), two packaging levels (with polyethylene and with clay nanocomposite films), and two chitosan coating levels (including chitosan coating and without coating) were selected and analyzed based on the completely randomized multivariate factorial design. The results showed that main and interaction effects of studied factors were significant on color parameters, weight loss, pH, Brix percentage, firmness, and elasticity modulus. Finally, the outputs indicated that the coated samples packed with the clay nanocomposite film had the most optimal mode in terms of the changes in physical, chemical, and mechanical properties during the storage period. The variations of the dependent parameters at 4 °C were less than that at 25 °C during the storage period. The results showed that shear force and stress in nanocomposite film are higher than polyethylene film. Therefore, the coated samples packed with the clay nanocomposite film could be used to improve the shelf life of strawberry fruit.

Effect of Gamma Radiations on the Quality and Shelf Life of Strawberry Fruit of the Uttrakhand Region

<div><p><em>Present study was conducted to investigate the effect of gamma radiations on the quality and shelf life of strawberries. The aim of this study was to evaluate gamma radiation doses in range of 0.3- 1.5 kGy. The irradiated strawberries were stored in ambient (temperature 25 +- 2<sup>o</sup>C, RH 70 %) and refrigerated (3 +-1<sup>o</sup>C, RH 80%) conditions. In samples treated with dose 1.2-1.5 kGy no decay was recorded up to 9 days of ambient conditions. Under refrigerated conditions, strawberry samples of unirradiated and irradiated in the range of 0.3-0.9 kGy started decaying after 14 days of storage. No decay was observed in the samples treated with 1.2-1.5 kGy up to 28 days of refrigerated storage. Dose of 1.2 kGy was significantly effective in reducing the weight loss and in maintaining the higher overall acceptability under both the storage conditions compared to the other treatments. This dose also proved effective in retention of significantly higher levels of total sugars compared to the other treatments. Thus, it was established that irradiating strawberries with dose of 1.2 kGy can prove beneficial in facilitating the marketing of the fruit to distant places other than the local markets, thereby benefiting the growers.</em></p></div>

Effect of Vacuum Microwave Drying on the Quality and Storage Stability of Strawberries

The aim of this study was to determine how vacuum-assisted microwave drying (VMD, 50C, 6 kPa for 3 h) affects the quality attributes and shelf life of dehydrated strawberries. Changes of quality attributes such as color, texture, and rehydration, shrinkage, polyphenol contents, antioxidant activity, and physicochemical and sensory properties were assessed after VMD. Vacuum packed, dehydrated strawberries were stored at 20C in the dark for 6 months. Decay of anthocyanins, flavonoids and polyphenols, and antioxidant activity was determined and modeled according to first-order kinetics. VMD resulted to minimum color difference. Texture changed by increased mechanical resistance and stiffness, and decreased toughness after VMD. Sensory attributes were between 3.5 and 4.3 on 5-point intensity hedonic scale. Anthocyanins were the most unstable components in strawberries after VMD and storage, assessing the strawberry shelf life to 68 days. Finally, VMD is a promising technology that can be used to maintain fruit quality and extend shelf life. Practical Applications Drying is particularly important for handling and distribution of agricultural products with high moisture content and limited shelf life such as fruits and vegetables. The main objective of drying is to reduce moisture content to a level where microbial spoilage and deteriorative chemical reactions of agricultural products are minimal. However, the degradation of nutrients in food during convective hot air drying results to quality loss. Therefore, new drying equipment and drying techniques have to be designed and studied. Vacuum-assisted microwave drying is an emerging dehydration method that may be efficient to preserve quality characteristics of food and additionally leads to shorten effective drying time. The purpose of this study was to determine the effects of vacuum-assisted microwave drying and subsequent product storage on the quality attributes and shelf life of strawberry fruits. This preservation technique may avoid freezing or refrigeration of fruit.