No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
The effect of pre-harvest and post-harvest aloe vera gel treatments on fruit quality and storage performance of table grapes
Abstract
This study investigated the impacts of pre-harvest, post-harvest, and combined pre-harvest+post-harvest Aloe vera gel treatments on various quality parameters of the ‘Red Globe’ grape cultivar during a 150-day storage period. The quality parameters assessed were weight loss, decay ratio, color attributes, firmness, soluble solids content (SSC), titratable acidity (TA), levels of total phenolics and total antioxidant capacity, as these are indicative of bioactive compounds. Post harvest Aloe vera treatment resulted in the lowest weight loss among three treatments, while the combined treatment surprisingly led to the highest weight loss. Pre-harvest treatments resulted in the lowest SSC values, while the combined treatments led to the highest values. Differences in TA value were not statistically significant, neither between treatments nor during the storage period. Storage duration alone significantly affected pH values. The Aloe Vera treatments significantly increased total phenols compared to the control group, and this increase remained consistent throughout the storage period. The combined treatments yielded the highest total phenols (3389.45 µg gallic acid equivalent/g fresh fruit). Similarly, Aloe Vera treatments significantly increased total antioxidant capacity (TAC) throughout the storage period. While the combined treatment yielded the highest TAC on day 150 (6.66 µMol trolox equivalent/g fresh weight), it negatively affected physical and chemical parameters. However, compared to other treatments, this combined approach significant boosted phytochemical levels. These findings suggest that for fresh table grapes, separate pre-harvest or post-harvest Aloe Vera treatments might be preferable. On the other hand, for those prioritizing elevated phytochemical content for health benefits, the combined application offers an option despite its drawbacks.
... Grape berries are exposed to various biotic and abiotic stress factors, especially fungi, bacteria, and viruses during the growth process [9]. Botrytis cinerea, one of these pathogens, causes gray mold disease, which is common in the postharvest life cycle of grapes and causes significant economic losses [10]. This necrotrophic pathogen affects fruit tissues by secreting various metabolites and enzymes during infection; it can maintain a high germination rate even at low temperatures [11]. ...
Fungal infections, particularly those caused by Botrytis cinerea, pose significant challenges to grape production worldwide, leading to substantial economic losses and reduced fruit quality. While conventional fungicides remain widely used, growing concerns about environmental impact and fungicide resistance have intensified the search for natural alternatives. Essential oil compounds (EOCs) have emerged as promising candidates for sustainable disease management. This study investigated the protective effects of thymol, eugenol, and 1,8-cineole on "Narince" grapes challenged by B. cinerea infection. The study revealed that essential oil combinations significantly reduced oxidative stress in B. cinerea-infected "Narince" grapes, with MDA (Malondialdehyde) levels decreasing up to 41.3 % compared to the control group. The TOS (Thymol + Eugenol+1.8-Cineole) combination demonstrated a remarkable 467 % increase in CAT (catalase) enzyme activity, while the Thymol (T) and 1,8-cineole (S) combination effectively mitigated oxidative stress by reducing POD (peroxidase) activity by approximately 26 % and regulating SOD (superoxide dismutase), MDA activity. The treatments effectively restored mineral content (particularly Potassium (K), Phosphorus (P), Nitrogen (N), Calcium (Ca) that was depleted by fungal infection. Moreover, EOCs applications led to substantial increases in anthocyanin content, especially malvidin-3-O-glucoside and petunidin-3-O-glucoside, along with elevated levels of phenolic compounds including gallic, vanillic, and trans-p-coumaric acid. These findings reveal that EOCs strengthen grape defense mechanisms against B. cinerea through multiple pathways: reducing oxidative stress, preserving mineral content, and enhancing beneficial compound accumulation. Our study provides valuable insights into the development of sustainable disease management strategies in viticulture, offering a promising alternative to conventional fungicides. The demonstrated efficacy of these natural compounds in protecting grape quality and health suggests their potential for integration into modern vineyard management practices, particularly in regions where fungicide resistance or environmental concerns are paramount.
... Contrary to many studies reporting that covering applications such as Aloe vera, chitosan, thyme oil, olive leaf extract and guar gum reduce weight loss (Dong and Wang, 2018;Nabifarkhani et al., 2015;Maqbool, Ali and Alderson, 2010;Serrano et al., 2017;Zam, 2019). Diaz-Mula, Serrano, and Valero (2012) and Dong and Wang (2018), Donat and Sucu (2024) reported that preharvest application of Aloe vera on grapes was not effective in reducing weight loss. Water loss in fruit is controlled by the cuticle, which has a complex structure. ...
The effects of 1% biofilm (ParkaTM) treatment regimes, initiated three (biofilm-3), two (biofilm-2), and one week (biofilm-1) prior to the commercial harvest, on fruit quality traits during the postharvest storage stage were investigated in this study. The treated fruit were stored at 0 ± 0.5°C and 90 ± 5% RH for 21 days. The application of biofilm treatments had no discernible effect on weight loss. In fact, biofilm-1 was found to have the opposite effect, resulting in increased weight loss. Respiration rates of biofilm-treated fruit were generally higher than those of control. Firmness of the biofilm treatments was higher than that of the control, both at harvest and during storage. Red coloration of the fruit was delayed by the biofilm treatments. Biofilm treatments caused a significant increase in the SSC of the fruit. The acidity of the control was lower than that of the biofilm treatments from the time of harvest until the 14th d. At the end of 21 d, there was no significant difference in acidity between the treatments. The effects of the treatments on vitamin C differed according to the date of measurement. At the end of storage, vitamin C was higher in fruit treated with biofilm-1 and biofilm-2. All biofilm treatments caused a significant increase in total phenolics, total flavonoids, anthocyanin content and antioxidant activity of the fruit, which was more evident in the biofilm-1 treatment. The results showed that biofilm treatments were more effective in maintaining fruit firmness and bioactive compounds during storage.
The goal of the current study was to determine how long grapes with aloe vera coverings suspended in water at concentrations of 0, 10, and 30% would last while stored in poly bags and open plates at varying temperatures between 0°C and 30°C in a refrigerator and incubator. The effectiveness of the Aloe Vera coating was evaluated using the data and the grapes' original shelf life. Aloe Vera-based coatings produced good gloss, and coating concentrations of 20% produced the best physicochemical and visual outcomes. The most efficient and suitable Aloe Vera coating concentration for extending the shelf life of grapes was discovered to be 20%. Additionally, it was discovered that using edible coating and packaging along with low temperature storage increases marketability by limiting moisture loss. In other words, employing an Aloe Vera gel coating can extend the shelf life of grapes and lessen fruit rotting brought on by fungus.
Edible coating is an environmentally friendly, safe, and effective practice to extend the physical and biochemical qualities of fresh commodities. The present study evaluated the effects of preharvest Aloe vera (AV) spraying 1 week before harvest (25%), postharvest AV coating (25%), and their combined use on the quality of table grape (‘Sultani Cekirdeksiz’ syn. ‘Thompson Seedless’) during cold storage at 1.0 ± 0.5 °C and 90 ± 5.0% relative humidity for 120 d. Berry adherence was significantly improved by preharvest AV pulverization by increasing the berry detachment force, a prime feature determining the storage and marketing lifetime of table grapes. Both preharvest and postharvest AV treatments remarkably delayed the loss in weight and maintained the rachis chlorophyll content and antioxidant capacity during the storage. Visual quality was obviously higher in grapes subjected to both treatments. Overall investigations showed that both treatments significantly maintained the storage lifetime of the grapes. Based on the findings, AV treatment as a natural and healthy compound could be used as a suitable alternative to extend the marketable period of table grapes and minimize postharvest losses.
This study aimed to investigate the effect of preharvest salicylic acid (SA) (2 and 3 mM) and postharvest Aloe vera gel (AV) coating (25% and 33%) on the postharvest characteristics of Vitis vinifera L. fruits stored 4 ± 0.5℃ for 32 days. The results showed that all SA + AV treatments significantly reduced the incidence of decay and weight loss of grapes. The principal component analysis (PCA) showed that SA (2 and 3 mM) combined with AV (25%) coating had the most significant effect on increasing the grape's ascorbic acid and anthocyanin content. Besides, SA (2 and 3 mM) combined with AV (33%) coating had a stronger promoting effect on solid soluble content, firmness, total phenol content, antioxidant capacity, titrable acidity, and peroxidase activity. Overall, it is concluded that foliar-applied SA alone was not effective in increasing physicochemical properties, and using AV coating after foliar-applied SA can have the greatest effect on traits. These results showed that the preharvest and postharvest treatments of grapes with SA and AV, respectively, could prolong the storage life of table grapes and maintain their quality.
Peach is a climacteric fruit characterized by a rapid maturation, high respiration level, weight loss, breakdown of texture, and interior browning. Fast tempering of the fruit and subsequent mold expansion caused a negative impact on the marketing. This study was carried out to estimate the synergistic influence of coating with Aloe vera gel (AVG) at 15% or 30% mixed with chitosan (CH) at 1.5% as a kind of natural polymers or calcium chloride (CaCl2) at 3% on physical and chemical features. We investigated the changes in antioxidant enzymes activities of peach fruits Prunus persica (L.) Metghamer Sultany. Fruits were kept at 3 ± 1 °C and relative humidity (RH) 85–90% for 36 days during two consecutive seasons (2020 and 2021). Results revealed that applying AVG at 30% blended with CH at 1.5% significantly impacted the storage period of peach fruits, reduced the ion leakage (IL), malondialdehyde (MDA), and lessened weight loss. The differences were significant compared to the other treatments and untreated fruits (control) that exhibited the higher values for IL, MDA, and weight loss in the 36th day. Moreover, fruit quality features such as firmness, total acidity (TA), total soluble solids (TSS), and skin color chroma (c*), hue angle (h) were also maintained. Furthermore, this combination was raised of phenolic content, antioxidant capacity (DPPH), antioxidant enzyme activity such as catalase (CAT), peroxidase (POD), and quench the generation of H2O2 and O2•−. It could be concluded that dipping peach fruits in AVG at 30% blended with CH at 1.5% retained the biological features of peach fruit at considerable levels during cold storing. Thus, this effective mixture can be utilized to prolong the storage and marketing period of peach fruits. Nevertheless, a more in-depth analysis is required for this edible coating to be successfully commercialized in the peach fruit post-harvest industry.
Low temperature storage is widely used to maintain the postharvest quality of table grape. However, grape clusters easily undergo deterioration without treatment during the storage time. The main goal of this study was to evaluate the effect of postharvest 1-methylcyclopropene (1-MCP), calcium chloride (1%) and ethanol (16%), and the combination of 1-MCP with calcium chloride and ethanol treatments on maintenance of quality of table grapes ‘Kyoho’ (Vitis vinifera × Vitis labrusca) under 5 °C and 0 °C storage. Changes in decay incidence, weight loss, rachis browning and quality indexes of grape clusters were investigated. The results were as follows: all treatments significantly reduced the decay incidence, weight loss, rachis browning at both low temperatures storage; 1-MCP had positive effect for reducing the decay incidence in early stage, but no effect in late stage; there are no significant variations of taste and color quality indexes under two low temperatures storage, regardless of the treatments. Overall findings suggested that the combination of 1-MCP with calcium chloride and ethanol treatment is suitable for short-term 0 °C storage, while for long-term 0 °C storage, calcium chloride (1%) and ethanol (16%) treatment should be selected.
The effects of storage temperature on postharvest storability, quality attributes and antioxidant enzyme activities of harvested Ponkan mandarins were investigated. Fresh fruits were randomly divided into four groups and stored at different temperatures [5 ± 1 °C (S5), 10 ± 1 °C (S10), 15 ± 1 °C (S15), and 20 ± 1 °C (S20 or control)] for 120 days. The results indicated that, compared with the control fruit, low-temperature storage at 10 °C significantly delayed the increase in fruit decay rate, weight loss, citrus colour index, respiration intensity, relative electrical conductivity, the accumulation of hydrogen peroxide and malondialdehyde, retarded the decline in L* value, retained high contents of total soluble solid, titratable acid, vitamin C, total phenol and total flavonoid, as well as higher activities of antioxidant enzymes – superoxide dismutase, catalase, peroxidase and ascorbic peroxidase. The principal component analysis results showed that low-temperature storage significantly maintained the postharvest quality of Ponkan mandarins, with fruit stored at 10 °C having no significant difference from the fruit stored at 5 °C, but markedly higher than those fruit stored at 15 °C. The comprehensive result of single-factor analysis and PCA showed that 10 °C could be used as the optimum storage temperature for improving the postharvest storability of Ponkan mandarins.
Red grape (Vitis vinifera L.) is easy to get perishable and wrinkles/wilt, brown in color, and soft fruit flesh. one of the benefits of edible coating is that it can protect products from
microbiological damage. The ability of aloe vera as an antimicrobial can be a potential ingredient for making edible coatings. Besides, the use of aloe vera as an edible coating is
also very easy and affordable (cheap). The purposes of this study are to determine the effect of glycerol addition and the best treatment of aloe vera edible coating on the quality of the red
grape. The experiment used a completely randomized design (CRD) as an experimental design with 4 treatment factors, namely the concentration of glycerol (P1=0%, P2=3%, P3=5%, P4=7%). Each concentration was repeated three times. The parameters observed were physicochemical characteristics (weight reduction, pH, total titrated acid), hedonic quality test (color, aroma, texture). The results showed that the treatment of 3% glycerol was the best treatment since it could maintain the condition of the fruit well during storage, especially weight
reduction, aromas, and textures. Parameters that highly affect the quality of red grapes are texture and weight loss.
Keywords: Aloe vera, Edible coating, Glycerol, Red grape.
In the present study, orange fruit was coated with 1 mmol L−1 salicylic acid (SA), 10 g L−1 acetic acid (AA), 5 g L−1 AA + 0.5 mmol L−1 SA, 10 g L−1 AA + 1 mmol L−1 SA, and 10 g L−1 carboxymethyl cellulose (CMC) solutions to improve the postharvest quality of orange over 35 days of storage. The weight loss, decay, TPC, TAA, and mold injury increased and the AAC decreased throughout the storage time. The control showed the highest TSS, weight loss, decay, and mold injury and the lowest TA, L*, and b* values than the treated samples. Meanwhile, CMC, SA, and 5 g L−1 AA + 0.5 mmol L−1 SA showed the highest AAC, TPC, and TAA. The loss or increasing rate of AAC, TPC, TAA, decay, and mold damage followed a first-order kinetic model in most cases. The SA samples obtained the highest sensory scores. Overall, the application of SA, AA + SA, and CMC, particularly SA can be recommended for improving the postharvest quality of orange fruit.
The aim of the study was to compare the quality of table grapes (cv. Italia) held on the vine compared to grapes stored in cold rooms with or without modified-atmosphere packaging (MAP). The grapes were harvested from 12 plants in 2 vineyards in the same area, differing for the age of the plant. Four- and a fourteen-year-old vines were cultivated with the "Apulia tendone" system. After the first harvest, grapes were divided into small clusters and used for storage treatments in air and in MAP. Samples of 400 g were packaged in polypropylene (PP) trays sealed with a polypropylene/polyamide (PP/PA) film with 20% CO2 in air. MAP and control samples were then stored in the same cold room at 0 °C. Initially and after 8, 21, and 28 days, grapes stored in air and MAP were compared to fresh harvested grapes, stored on the plants. Quality attributes included color, texture, maturity index, phenols, antioxidant activity, sugars, organic acids, sensory parameters, and volatile compounds. The results obtained demonstrated that grapes held on the plant and in MAP showed better quality in terms of appearance scores compared to grapes stored in air. In particular, the application of high CO2 contributed to reduce the deterioration rate of the clusters, minimizing weight loss, and delaying degradation processes, and this particularly for grapes from the 14-year-old vine, where grapes held on the plant degraded faster than grapes in the younger vines. Most volatile compounds did not change their concentration with the storage treatment, except for ethyl acetate and ethanol, which increased in MAP at the end of storage, and to some compound responsible for green odor. In conclusion, keeping the grapes on the plant can be considered a good agronomic practice to preserve the quality, whereas MAP can be applied to better maintain postharvest quality of the product throughout storage and distribution.
Aloe vera (ALV) with its unique nutritional profile is being used for food, health, and nutraceutical industries globally. Due to its organic nature, ALV gel coating has created lot of interest for exploring its potential in extending the shelf and storage life of fresh produce. ALV gel coating plays imperative role in delaying fruit ripening by lowering ethylene biosynthesis, respiration rate, and internal metabolic activities associated with fruit softening, color development, enzymatic browning, and decay. ALV gel coating reduces the microbial spoilage due to its antifungal properties and maintains visual appearance, firmness, sugar: acid ratio, total antioxidants, and phenolic contents with conserved eating quality. ALV coated fruits and vegetables showed reduced weight loss, superoxide ion (
O
2
-
∙
), hydrogen peroxide (H2 O2 ), ion leakage, and soluble solids content and exhibited higher acidity, anthocyanins, ascorbic acid, catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) activities. It also delayed the enzymatic browning by inducing peroxidase (POD) activity during storage. Recent local studies also revealed that ALV gel coating markedly conserved higher consuming quality and extended storage period (>1.34-fold) of different fruits and vegetables. Overall, Aloe vera gel coating alone or in combination with other organic compounds has shown great potential as a food-safe and eco-friendly coating for maintaining the quality of fruits and vegetables over extended period and reducing postharvest losses in the supply chain. PRACTICAL APPLICATIONS: ALV gel is a plant-based natural coating of eco-friendly nature. The present review summarizes the updated information of ALV gel coating application, methods of extraction, combinations with other postharvest coatings, and its impact on quality of various fruits and vegetables. It also provides future insights for the development of commercially applicable ALV gel coating protocols through simulation studies. So, being a natural coating, ALV gel has tremendous potential to be used in fruit and vegetable industries around the globe.
Aloe vera gel provides numerous health benefits and is considered as one of the best coating materials, which is edible, safe, and biodegradable. It facilitates a barrier against moisture and gas exchange, conserves the firmness, color, and flavor of the fruits and vegetables. Besides, owing to the antimicrobial and antioxidative properties, Aloe vera coating provides reduced microbial proliferation and improved antioxidant activity of the stored produce. Hence, Aloe vera coating has been used as a noble edible coating for fresh produce. This review aims to highlight the application of Aloe vera gel coating alone or together with other functional compounds in order to extend postharvest shelf life and preservation quality of fresh and minimally processed fruits and vegetables. This study also summarizes relevant biological activities and compositional characteristics of the gel. Some challenges and future aspects of the application of Aloe vera coating have discussed as there is a growing interest in this unique edible coating. This information will help the food processors to identify the most effective Aloe vera coating concentration alone or in combination with other functional ingredients for a variety of fresh and minimally processed fruits and vegetables.
Ready-to-eat products are damaged by various factors, including exposure to O2 and CO2, extreme temperatures, and rapid decay,
due to trauma during processing. +e use of natural antimicrobial agents and antioxidants might extend the shelf-life of the fruits.
+e aim of this work is to investigate the effects of four different antibrowning and gelling agents added into the Aloe vera gelbased edible coatings and applied to fresh-cut papaya. EC1 treatment consists of Aloe vera gel (30% v/v), EC2 contains CaCl2 (5%
v/v), EC3 contains K carrageenan (0.5% v/v), and EC4 contains sodium alginate (1.5% v/v) and K carrageenan (0.5% v/v). +e
fruits treated with EC2 showed the best results while maintaining high values in terms of firmness (that differ from the control of
42.5%), soluble solid content (that differ from the control of 14.6%), and titratable acidity (that differ from the control of 49%).
Hence, the addition of CaCl2 also reduces the ripening rate and loss of color without altering the product’s sensory qualities. EC3
and EC4 treatments have provided an oxygen barrier and reduced respiratory rate, increasing the firmness retention and keeping a
high C∗ value thanks to K carrageenan and sodium alginate.
Brassinosteroids (BRs) are a class of polyhydroxysteroids that have been recognized as a “sixth class of plant hormones.” Exogenous application of BRs affects a broad spectrum of physiological responses, secondary metabolite accumulation, and resistance against stress factors in plants. In this study, the effects of pre-harvest 24-epibrassinolide (24-eBL) applications on the accumulation of antioxidant compound, yield, and quality properties of Alphonse Lavallée grape cultivar were examined. 24-eBL was applied to vines with 13 combinations including different application times and concentrations of 24-eBL (0.2, 0.4, 0.6, and 0.8 mg L⁻¹) and control. It was found that 24-eBL increased yield, quality, and antioxidant compounds in grapes when it was applied at appropriate concentration and application time. The concentration 0.2 mg L⁻¹ of 24-eBL applied to vines at three times (7 days after berry set + veraison + 30 days after veraison) was the most suitable application providing the highest yield and some quality properties such as cluster weight, berry weight, and specific gravity. Concentrations 0.6 and 0.8 mg L⁻¹ of 24-eBL applied at veraison to vines can be suggested for total phenolics, β-carotene, ascorbic acid, and trans-resveratrol accumulation for Alphonse Lavallée as a practical application, while the application consists of 0.6 mg L⁻¹ of 24-eBL and 7 days after berry set + veraison + 30 days after veraison seems to be the best treatment for anthocyanin content.
Nowadays, fruits and vegetables are highly demanded in the market because of its nutritional value. Fruits and vegetables have short shelf life due to its perishable nature. About 30% fruits and vegetables are affected or damaged by insects, microorganisms, pre and post harvesting conditions during transport and preservation. Preservation of fruits and vegetables is a big challenge for world. Edible coating is an effective method to solve this problem. It provides protective edible covering to fruits and vegetables. It is beneficial for consumers and environment. Today herbal edible coatings are used as a nutraceutical and beneficial for consumer health. Edible coatings are of different types such as hydrocolloids, lipids and plasticisers. These have good barrier properties to O2, CO2, moisture and water vapour.
The goal of the study was to determine the differences in phytochemical components of mulberry (Morus laevigata) fruits at different stages of ripeness. In this study, the highest total phenolic (1310.3 µg gallic acid equivalents/g fresh weight) and anthocyanin (925.6 µg cy-3-glu/g fresh weight) contents and antioxidant capacity (12.8 µmol trolox equivalents/g fresh weight) were observed in black ripening stage. The major sugars in mulberry fruits were fructose (17.55 g/kg). It was determined that the main organic acid in mulberry was citric acid ranging from 8.97 g/kg (pink stage) to 5.80 g/kg (black ripening stage), followed by malic acid ranging from 0.31 (pink ripening stage) to 5.67 (black ripening stage) g/kg. Looking at the contents of phenolic compounds, chlorogenic acid (average 27.48 mg/100 g) was found to be the predominant phenolic compound. Current study shows that M. laevigata fruits are a good source of healthy phytochemicals.
BACKGROUND: Table grape is a non-climacteric berry, sensitive to water loss and gray mold during postharvest storage. OBJECTIVE: To assess the effect of passive and active modified atmosphere packaging on quality parameters of minimally processed table grapes.
METHODS: ‘Red Globe’ minimally processed table grapes were dipped in a sodium hypochlorite solution and irradiated with ultraviolet-C, before being packaged in a rigid polypropylene boxes, sealed with a micro perforated polypropylene film (PP) or a continuous polyethylene film, with: a) 5% O2 + 15% CO2 + 80% N (PET1); b) 20% CO2 + air (PET2). Samples were stored at 5◦C for 21 days plus and additional 6-day period at 20◦C to simulate shelf-life.
RESULTS: No chemical and sensory changes during storage occurred in fruit sealed in PP packages. The high in-package CO2 partial pressure which increased in PET1 and PET2 combined with the reduced concentration of O2, increased decay incidence, stimulated anaerobic respiration, hastened soluble sugars degradation, produced higher weight loss and altered sensory quality. CONCLUSIONS: Quality of minimally processed ‘Red Globe’ was better maintained in PP packaging where air-composition was not changed than in PET1 and PET2 where toxic levels of CO2 and reduced tension of O2 hastened quality loss and increased decay incidence.
Keywords: Decay, MAP, ready-to-eat, Red Globe
A novel edible coating based on natural Aloe vera gel in combination with calcium chloride (2%) and
citric acid (1%) was used as a mean of preservation to maintain the quality and safety in table grape (Vitis vinifera L.
cv. Askari) during cold storage at 4°C temperature and 85 ± 5 % relative humidity for 35 days. Coated clusters
delayed the increase in weight loss and soluble solids content, retained greater ascorbic acid and titratable acidity
contents than control. Moreover, the sensory analyses revealed beneficial effects in terms of delaying rachis
browning and dehydration, which was significantly lower in treated than control fruit.
Investigations were carried out to verify the potential of putrescine and spermidine as a postharvest dip treatment for maintaining quality and extending storage life of table grapes (Vitis vinifera L.) cv. Flame Seedless during the 2012 and 2013 seasons. Grape clusters were manually harvested at the commercial mature stage and were dipped in different concentrations (0.0, 0.5, 1.0 and 1.5 mM) of putrescine and spermidine, and then stored at 3–4 °C, and 90–95% RH. Evaluation of physico-chemical parameters and other fruit quality attributes were made at 0 day (before treatment) and at 30, 45, 60 and 75 days of storage. Putrescine and spermidine at the lowest dose (0.5 mM) effectively maintained berry firmness, peel colour (L*, C*, h°) and stabilized anthocyanins as well as suppressing the activity of pectin methylesterase and reducing the rate of electrolyte leakage. The polyamines also retarded the degradation of TSS and TA while maintaining higher total phenol content and reduced decay incidence. Putrescine and spermidine at 1.0 mM exhibited almost similar effects with a 0.5 mM dose. The highest doses (1.5 mM) of both polyamines showed detrimental effects, especially on weight loss, decay incidence, rachis browning and organoleptic properties, as found in the control group, which was commercially acceptable only up to 45 days. Furthermore, analysis of linear regressions and correlations showed that many quality parameters were interdependent. The postharvest dip treatment of spermidine or putrescine at a dose of 0.5 mM for 5 min could be an effective means for prolonging storage and increasing shelf-life of ‘Flame Seedless’ grapes.
The effects of preharvest spray with Cryptococcus laurentii combined with chitosan coating after harvest on decay and quality of table grapes during storage periods were evaluated in the present study. Preharvest spray with C. laurentii (PreA) significantly decreased decay index (DI), and postharvest chitosan coating (PCC) enhanced the effectiveness of the pre-harvest spray when fruits were stored at 0°C. PreA combination with PCC increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) of fruit in storage. PreA+PCC treatment was effective in reducing weight loss of fruits by 85% at 17d storage and 38% at 42d storage as compared to PreA alone at the same stage. In addition, PreA enhanced the ratio of soluble solids content (SSC) to titratable acid (TA) by 12% at harvest time, 7% at 17d storage and 25% at 42d storage, mainly by increasing SSC and decreasing TA in fruit stored at 0°C. These results suggested that integration of preharvest spray with C. laurentii and postharvest chitosan coating treatment may be a promising management strategy for decay control and quality maintenance of table grapes.
A colour index for the objective determination of the colour in red table grapes is described. This index is based on the CIELAB values. A statistical study revealed a high correlation between L∗ and b∗, while a∗ was not a representative parameter. The usefulness of this index is investigated to classify the red grapes depending on their external colour. The proposed colour index for red grapes (CIRG) is based on the parameters L∗ (lightness), H (hue angle) and C (chroma) and its expression is “” All the colour indexes previously proposed were defined in fruits whose colour varied between yellow and red, and, therefore, were not suitable for red grapes which show a dark violet colour. This new index showed a good linearity with the visual colour of the berries and distinguished between sample groups of different external colour.
The measurement of antioxidant capacity in fruits differs from that of other biological samples due to their low pH and very low lipophilic antioxidant capacity. In this report, we present a modified 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method for fruits and compare its performance with the other commonly used antioxidant methods of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The antioxidant capacity and reaction kinetics of four phenolic compounds, two antioxidant standards, and five fruits were also investigated. The modified ABTS method prepared at a pH of 4.5 with sodium acetate buffer is highly stable and easily applied to fruit samples as compared to the standard (pH 7.4) version. The measured antioxidant capacity of samples varied with the assay method used, pH, and time of reaction. Traditional antioxidant standards (trolox, ascorbic acid) displayed stable, simple reaction kinetics, which allowed end point analysis with all of assays. Of the phenolic compounds examined, chlorogenic and caffeic acids exhibited the most complex reaction kinetics and reaction rates that precluded end point analysis while gallic acid and quercetin reached stable end points. All fruit extracts exhibited complex and varied kinetics and required long reaction times to approach an end point. Because the antioxidant capacity of fruit extracts is a function of the array of individual antioxidants present, accurate comparisons among fruit samples require that reaction times be standardized and of sufficient length to reach steady state conditions and that more than one assay be used to describe the total antioxidant activity of fruit samples.
The present study evaluated impact of pre-harvest foliar spraying with chitosan (2% and 3%) and post-harvest Aloe vera gel (AVG) coating (25% and 33%) to determine the quality of table grape during storage. The results showed that both treatments significantly influenced the storage lifetime of this fruit. In addition, the chitosan and AVG combinations minimized the incidence of decay and reduced the weight loss more than that of chitosan, AVG and control samples. 25 days once the foliar application of chitosan 3% with AVG 33% coating extending the storage life of fruit up to 15 days by significantly reducing decay index, malondialdehyde, weight loss and polyphenol oxidase also, maintaining the overall quality index, firmness, antioxidant capacity, peroxidase, total phenols, anthocyanin, SSC and vitamin C. Based on the findings, these natural compound treatments could be considered as suitable alternatives to extend the marketable period of table grapes and minimize post-harvest losses.
Aloe vera L. is a common succulent plant that has been used for centuries regarding their healing properties and health benefits. Nowadays, scientific investigations on its gel have gained more attention because of its interesting antioxidant and antimicrobial properties. Also, the food industry encounters the need to preserve safety and quality of fresh produce; fruits and vegetables are in high demand due to their reported health benefits, and fresh-cut products are a new trend that meets the restless needs of the society. Edible coatings are an effective way to maintain freshness of these products, extend their shelf life, and even act as an alternative to modified atmosphere packaging to be used in conventional packaging. Aloe vera gel is a natural hydrocolloid, composed mainly by polysaccharides, that has been applied in the last years on fruits and vegetables. It can act as a semipermeable barrier for gases and water vapor, decreasing the respiration and ripening processes of the fruit, thus maintaining weight, firmness and valuable compounds. Its antioxidant and antimicrobial properties make it also an interesting material for increasing the shelf-life of fruits and vegetables. This review aims to describe the preparation and preservation of Aloe vera gel as well as the properties and compounds that are effective against oxidation and microbial growth. Moreover, the recent findings of its use – with or without additives – as an edible coating on fruits and vegetables have been widely detailed, showing that Aloe vera gel is a promising preservative method in this industry.
In this study, the impact of chitosan in combination with aloe vera gel was investigated on the storage life of mango fruits. Mango samples were coated with 1% chitosan (CTS) and 1% chitosan + aloe vera gel (CTS + AVG), before storing at 12 ± 1 °C for 28 days and shifting to 25 ± 1 °C for 5 days. Results demonstrated that both coatings significantly (p ≤ 0.05) influenced the storage life of mango fruits, but CTS + AVG minimized the incidence of decay, and reduced weight loss, respiration rate, and ethylene production to a greater extent than CTS and control samples. In addition, fruit quality parameters such as titratable acidity, total soluble solids, fruit firmness, ascorbic acid, and peel color were also retained by the combined treatment. Furthermore, sustained phenolic content and antioxidant activity confirmed the effectiveness of this treatment. It was concluded that chitosan coating in combination with aloe vera gel suppressed diseases and maintained the natural properties of mango fruit during postharvest storage. Therefore, chitosan–aloe vera combination can be used to extend the storage life of mango fruit, however, more in-depth studies are required for successful commercialization of this organic, edible coating in the mango fruit industry.
The detrimental health implications of chemical preservatives in fruits have necessitated exploitation of safe and natural alternatives such as edible gums. This work studied shelf-life extension in grape (Pinot noir) under cold storage by xanthan gum (XAN) coatings enriched with ascorbic acid (XANAS) and citric acid (XANCI). Standard scientific methods were used to examine some sensory (color, texture—resilience and hardness), enzyme, anthocyanine and antioxidant activities. Also, the reaction rate mechanism was examined through modeling of selected shelf-life indicators; color change, weight loss, and antioxidants. The results revealed that, Xanthan gum and its acid modified coatings significantly (p < 0.05) suppressed polyphenol oxidase, ascorbic acid oxidase, polymethyl etherase acitivies and maintained the structural integrity of the grape during the 21 days storage period. Weight loss (%) in the grape samples was 13.66 < 13.98 < 14.16 < 15.64 in the order XANAS < XANCI < XAN < CONTROL whilst ferric reducing antioxidant power (FRAP) activity was 150.23 > 143.18 > 136.49 > 104.5 mg/100 g AEAC corresponding to XAN > XANAS > XANCI > CONTROL. Significantly (p < 0.05) higher phytochemical contents were observed in the gum coatings compared to the control. Through statistical parameters such as the coefficient of determination (R²), root mean square error (RMSE) and reduced Chi square (χ²), the second-order polynomial model predicted precisely the decomposition of color, weight loss and FRAP of grape. Color deterioration was attributed to changes in b* parameter as a result of phenolics and phytochemical decompositions resulting from enzymatic activities. Conclusively, acid modified xanthan gum coatings could preserve phytochemicals, color, antioxidant and textural properties of grape in cold temperature storage.
This study was conducted to determine the effects of Aloe vera (AV) and modified atmosphere packaging (MAP) on physiological and chemical quality attributes of cherry laurel (Prunus laurocerasus L.) fruit during the cold storage at 0 ± 0.5 °C and 90 ± 5% RH. Throughout the storage, fruit weight and firmness losses were delayed with AV and MAP treatments. At the end of storage, the respiration rate of fruit treated with MAP was lower than the control and AV-treated fruit. Similarly, ethylene production of MAP and AV-treated fruit was lower than the control. At the end of storage, the highest hue angle was obtained from the control, whereas the lowest hue angle was measured in AV + MAP. Decay rate of AV and MAP-treated fruit was lower than the control. Vitamin C, total flavonoids, total monomeric anthocyanin and antioxidant activity of fruit treated with AV and MAP was higher than the control. The astringency of AV and AV + MAP-treated fruit was higher than the control at the end of storage. This study revealed that AV gel and MAP treatments were effective in maintaining quality and bioactive compounds of cherry laurel fruit.
The effects of pre-harvest methyl jasmonate (MeJA) treatments on fruit quality attributes and bioactive compounds of sweet cherry fruits (Prunus avium L. cvs. 0900 Ziraat, Regina and Sweetheart) harvested at optimal and late harvest dates were investigated in this study. Measurements revealed that MeJA treatments were quite effective in retention of fruit flesh firmness of all three cultivars. It was observed that harvest could be delayed at least a week with MeJA treatments through maintaining flesh firmness. MeJA treatments slowed down color changes in all three cultivars. MeJA treatments did not have significant effects on fruit mass and geometric mean diameters, but decreased soluble solids content and titratable acidity of the fruits. In all three cultivars, total phenolics, antioxidant capacity and total monomeric anthocyanin values decreased with MeJA treatments. Delayed harvests increased bioactive contents of both the control and MeJA-treated fruits.
The development of biologically glorious experimental process for the synthesis of nanoparticles is an important emerging branch of nanotechnology. Gold nanoparticles (AuNPs) can be easily synthesized, functionalized and are biocompatible. In the present work AuNPs were synthesized by an eco-friendly, fast, one-pot and green synthetic route using Longan fruit juice as a reducing, capping and stabilizing agent. The AuNPs showed surface Plasmon resonance at around 555 nm. The spherical shape, fine dispersion, average size (25 nm), crystalline structure and elemental composition were characterized by high resolution transmission electron microscopy (HRTEM), X-Ray diffraction (XRD) and Energy-dispersive X-Ray spectroscopy (EDS). The capping and stabilizing molecules were characterized by Fourier transform infrared Spectroscopy (FTIR). The AuNPs found to be unique in respect of mono-structural morphology and greater yield as compared to other bio-synthesized AuNPs. Furthermore, the cytotoxicity of AuNPs found to be potent agent against human breast cancer cell lines MCF-7. AuNPs exhibited significant antioxidant activity and fluorescence emission. These biomaterials can be used for broad biomedical applications.
Organic table grape production has several disease and decay problems mainly due to Botrytis cinerea fungus. These problems are enhanced when the crops are located in wet areas or seasons, and with late cultivars grown in southern Spain. The effect of Aloe vera treatment applied preharvest under high relative humidity conditions on organic 'Crimson Seedless' table grape was evaluated. The use of A. vera reduced the microbiological counts at harvest (especially moulds), and this reduction was maintained during post-harvest storage. Additionally, the changes in quality parameters, such as firmness and colour during postharvest were reduced with the preharvest A. vera treatment. Furthermore, the percentage of rotten berries per cluster at the end of storage was lower in A. vera-treated (3%), compared with control fruit (13%).
Components of variance were estimated for 10 strawberry ( Fragaria × ananassa ) color traits to determine their relative importance and to design optimal sampling strategies. The color attributes of >2000 fruit from 47 genotypes from the Univ. of California Strawberry Improvement Program were evaluated over three harvest dates (HDs) in one growing season. Measurements were obtained for a moderate number of fruit from each genotype on each date, and two measurements were obtained for each trait on all fruit. Variances for HDs were nonsignificant or small (0% to 8% of the total variance). Genotype × date variances were highly significant but small (≤6% of the total) for all color traits except internal hue (14% of the total). For external color traits, the within-fruit variance was greater than the among-fruit variance (16% to 64% and 0% to 14% of the total, respectively). For internal color traits, the among-fruit variance was greater than the within-fruit variance (20% to 37% and 9% to 19% of the total, respectively). Obtaining two measurements per fruit for several fruit on one HD is an efficient strategy for characterizing a genotype's fruit color; seven to 22 fruit are needed to estimate a genotype's fruit color within 2 units (Commission Internationale de L'Eclairage L * a * b * or degrees) with 95% confidence.
Surface coatings and films can provide an alternative for extending the postharvest life of fresh fruits and vegetables. The objective of the research reported here was to evaluate the effect of chitosan and polyethylene wax (PE) coatings on storage of Xinjiang Hami melon at ambient temperature. The antimicrobial effect of natamycin on the two main pathogenic fungi of Hami melon alone and when added to the coatings was investigated. After 20 days the weight loss of coated Hami melon was 4.37%, decay area was 4.26cm2 for each melon, the ascorbic acid content was 94.4mgkg−1, the pH value was 5.83. Application of natamycin in combination with the bilayer films decreased decay severity and weight loss during storage.
Gray mold, caused by Botrytis cinerea, is the main postharvest decay of table grapes. It can develop in the vineyard and spread rapidly among berries after harvest, during long distant transport, cold storage and shelf-life. In conventional agriculture, bunches are sprayed with fungicides after flowering, at pre-bunch closure, at veraison, and later, depending on the time of harvest. Harvested bunches are usually stored in the presence of sulfur dioxide. However, the use of synthetic fungicides and of sulfur dioxide is not allowed on organic grapes and the study of alternative methods to control postharvest decay has developed over several decades, along with the demand for safer storage methods. This review summarizes the results published in the field within the last 5 years (2006–2010). We can group these approaches as follows: (i) biocontrol agents; (ii) natural antimicrobials; (iii) GRAS type decontaminating agents; and (iv) physical means. Two biocontrol agents, Muscodor albus and Hanseniaspora uvarum, have shown equal or better effectiveness than conventional methods to control gray mold of table grapes in laboratory scale experiments. Currently, the bottleneck for the commercial use of biocontrol agents is that the registration process is comparable to that of fungicides, with similar costs but often with a narrower market. This delays their transition from experimental to practical use. Natural antimicrobials, such as salts, chitosan, and plant extracts, have demonstrated good results and often have been applied in various scales. Several GRAS-classified sanitizers have been tested to extend postharvest storage of table grapes, including acetic acid, electrolyzed oxidizing water, ozone, and ethanol. Physical technologies involving variations in temperature, UV-C irradiation, pressure or changing atmospheric composition, are all postharvest practices which require significant adaptation by an industry which is accustomed to minimal intervention during harvest. Overall, the use of ozone and of calcium chloride are two promising examples of treatments that are beginning to be adopted on a commercial scale. The requirements for the optimal treatment of grapes against gray mold before harvest or during storage are summarized.Highlights► Alternative means to control decay of table grapes are mostly restricted to the level of research. ► Most of the alternative approaches have been evaluated only at the laboratory scale. ► Treatment with calcium chloride in the vineyard is common in several areas. ► Application of ozone during storage is being practiced at the commercial level. ► A combination of treatments before and after harvest can achieve sufficient decay control.
White seedless table grapes (Vitis vinifera cv. Autumn seedless) were stored under several gas treatments for up to 60 days at 0 °C followed by 7 days in air at 15 °C. To generate a modified atmosphere packaging (MAP) of 15 kPa O2 and 10 kPa CO2, a 35 μm thick microperforated polypropylene (PP) film with and without 0.7 g Na2S2O5 kg−1 was used. A controlled atmosphere (CA) of 5 kPa O2+15 kPa CO2 and continuous exposure to 0.1 μl l−1 O3 enriched air were also tested. As a control, macroperforated PP film was used. After shelf life, control berries showed the highest decrease in lightness and greenness while slight changes for gas-treated berries were found. At any time, no noticeable changes in firmness, SSC, pH, titratable acidity, maturity index, aroma and softness were detected. At the end of the experiment, severe browning of the rachis in control clusters occurred, due to the high weight losses reached (9.65%). Control clusters showed the highest fungal infection (over 9%), mainly caused by Botrytis cinerea. Visual appearance and eating texture of berries under gas treatments were higher after shelf life than in control fruit, with no differences among treatments except for CA-treated grapes. A progressive increase in the total sugar contents in all treatments was found. Glucose and fructose, in almost equal quantity, were the main sugars. Principal organic acids were tartaric and malic, and compared to values at harvest, no differences for any treatment at any sampling time were found. As a main conclusion, the gas treatment could be an alternative to replace the use of SO2 for keeping quality of ‘Autumn seedless’ grapes. MAP with 15 kPa O2+10 kPa CO2 provided the best results and also had a lower cost.
The quality of late-harvested (early December) ‘Aledo’ table grapes, during storage at 2±1 °C followed by a period of 4 days at 20 °C in a slightly CO2 enriched atmosphere in combination with generators of SO2 in cardboard boxes, was evaluated. The changes in different biochemical parameters indicative of grape quality, such as weight, texture, colour, sugars, organic acids and fungal attacks, was determined. The best quality maintenance was achieved by combining the use of generators of SO2 with a slightly CO2 enriched atmosphere. The rates of weight, texture and colour losses were slowed, and both fungal attack and the rachis drying were delayed. During storage at 2 °C, the levels of glucose, fructose and sucrose remained unchanged under all the tested conditions, while levels of tartaric and citric acids showed a sharp increase. However, a slightly CO2 enriched atmosphere, SO2 microgenerators and their combination extended the storage period of late-harvested ‘Aledo’ table grapes without relatively affecting their organoleptic characteristics.
Aloe vera gel was added at several concentrations on potato dextrose agar (PDA) to test its efficacy on inhibiting mycelium growth of two common fungi responsible for fruit decay (Penicillium digitatum and Botrytis cinerea). For both fungi, the inhibition of mycelium growth rate increased with Aloe concentration, although to gain the same inhibition the necessary A. vera gel concentration was 3-fold higher for B. cinerea than P. digitatum. Overall, the dose of 250 mL L−1 led to 4- and 2-log reductions of mycelium growth for P. digitatum and B. cinerea, respectively. Based on these results, A. vera gel at 250 mL L−1 was applied as a preharvest treatment to table grape vineyards 1 or 1 and 7 days before harvesting. Fruit were cold-stored for 35 days and sampled weekly. Respiration rate and weight loss were significantly reduced in treated samples, while ripening parameters such as colour and fruit firmness were significantly delayed. Both mesophilic aerobics and mould and yeasts counts were significantly lower at harvest in treated samples, the effect being persistent during storage. At the end of the experiment, the percentage of rotted berries was significantly lower in treated than in control fruit. From these results it could be inferred that A. vera could be considered as a promising preharvest treatment to maintain table quality during postharvest storage.
A novel edible coating based on Aloe vera gel, accordingly to our developed patent (SP Patent Filed P200302937), has been used as postharvest treatment to maintain sweet cherry quality and safety. During cold storage, uncoated fruit showed increases in respiration rate, rapid weight loss and colour changes, accelerated softening and ripening, stem browning and increased microbial populations, these processes being more intense during the shelf life periods. On the contrary, sweet cherry treated with A. vera gel significantly delayed the above parameters related to postharvest quality losses, and storability could be extended. The sensory analyses revealed beneficial effects in terms of delaying stem browning and dehydration, maintenance of fruit visual aspect without any detrimental effect on taste, aroma or flavours. As far as we aware, this is the first time A. vera gel is used as an edible coating in fruit, which would be an innovative and interesting means for commercial application and as alternative of the use of postharvest chemical treatments.
Scientific investigations on Aloe vera have gained more attention over the last several decades due to its reputable medicinal properties. Some publications have appeared in reputable Scientific Journals that have made appreciable contributions to the discovery of the functions and utilizations of Aloe--"nature's gift." Chemical analysis reveals that Aloe vera contains various carbohydrate polymers, notably glucomannans, along with a range of other organic and inorganic components. Although many physiological properties of Aloe vera have been described, it still remains uncertain as to which of the component(s) is responsible for these physiological properties. Further research needs to be done to unravel the myth surrounding the biological activities and the functional properties of A. vera. Appropriate processing techniques should be employed during the stabilization of the gel in order to affect and extend its field of utilization.
A novel edible coating based on Aloe vera gel obtained according to SP Patent Filed 200302937 has been used as a means of preservation to maintain the quality and safety of cv. Crimson Seedless table grapes during cold storage and subsequent shelf life. Table grapes have a crucial economic value as a dessert fruit, but once harvested show a reduction of shelf life due to a rapid loss of quality. Uncoated clusters showed a rapid deterioration with an estimated shelf life period of 7 days at 1 degrees C plus 4 days at 20 degrees C, based on the fast weight loss, color changes, accelerated softening and ripening, rachis browning, and high incidence of berry decay. On the contrary, those clusters treated with A. vera gel significantly delayed the above parameters related to postharvest quality losses, and storability could be extended up to 35 days at 1 degrees C. Interestingly, this edible coating was able to reduce the initial microbial counts for both mesophillic aerobic and yeast and molds, which significantly increased in uncoated berries over storage. Moreover, the sensory analyses revealed beneficial effects in terms of delaying rachis browning and dehydration and maintenance of the visual aspect of the berry without any detrimental effect on taste, aroma, or flavors. To the authors' knowledge, this is the first time A. vera gel has been used as an edible coating in fruits, which would be an innovative and interesting means for commercial application and an alternative to the use of postharvest chemical treatments.
Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to our developed patent (SP Patent P200302937) and then stored for 35 days at 1 degrees C, and the subsequent shelf life (SL) was monitored at 20 degrees C. Uncoated clusters showed a rapid loss of functional compounds, such as total phenolics and ascorbic acid. These changes were accompanied by reduction of the total antioxidant activity (TAA) and increases in total anthocyanins, showing an accelerated ripening process. On the contrary, table grapes coated with Aloe vera gel significantly delayed the above changes, such as the retention of ascorbic acid during cold storage or SL. Consequently, Aloe vera gel coating, a simple and noncontaminating treatment, maintained the functional properties during postharvest storage of table grapes.
Effects of aloe vera gel on the mechanical and thermal properties of nanocomposite produced from biopolymer blends
- A Ö Agirgan
Influence of vine crop load on ‘Redglobe’ table grapes
- Dokoozlian
The relationship between fruit texture and storage character in grapes
- Huiling
Importance of colors in consumption and health
- Özcan