Non-bagged Fruit Research Articles

Effects of paper pouches of different light transmittance on the phenolic synthesis and related gene expression in peach fruit

Bagging is a vital cultivation measure for producing high-quality peach fruit, which affects the appearance and internal quality of the fruit by mainly intervening in its exposure to light. However, it is not entirely clear whether bagging affects the content of phenolic compounds or which compounds are most sensitive to bagging treatment, and the regulatory role of bagging on phenolic synthetic-related genes is also unknown. In this experiment, four peach cultivars, 'BJ', 'XH', 'RG', and 'HYT', were bagged with four different types of bags at 50 days after full bloom, with no bag as control, and all fruits were harvested at the commercial maturation stage. The study found that bagged fruits had higher L*, b*, and h° values but lower a* and C* values than non-bagged fruits. Different cultivars and different phenolics exhibited different sensitivities to bagging treatments. Light intensity not only played a decisive role in the accumulation of anthocyanins in peach fruit but also had a strong and widespread impact on other phenolic substances. Overall, light not onlly significantly promoted the accumulation of cyanidin 3-glucoside, cyanidin 3-rutinoside, epicatechin, and rutin but also increased the accumulation of catechin, chlorogenic acid, and neochlorogenic acid to some extent, while shading by bagging inhibited the accumulation of these phenolics. Correspondingly, high light induced the upregulation of most structural genes and transcription factors, including PpPAL1, PpC3H1, PpC3H2, PpDFR, PpLDOX, PpUFGT, and PpMYB10.1, while low light inhibited the expression of these genes in the four varieties. In addition, PpHY5 homolog PpHYH was induced by high light, which might participate in the biosynthesis of the light-regulated phenolic in peach fruit. This study lays the foundation for further analysis of the regulation mechanism of light on the synthesis of phenolic compounds in peach fruit.

Effect of pre-harvest fruit bagging on biotic stresses and postharvest quality of banana

A study was conducted to determine the impact of pre-harvest fruit bagging on banana maturity, pest and disease management, and postharvest quality. The bunch was wrapped in a variety of bags, including white polythene bag, blue polythene bag, muslin cloth bag, gunny bag, brown paper bag and non-bagging (control). The study was designed as a randomized complete block design (RCBD) with three replicates. The results showed that banana bunch covered with brown paper bags were ready to harvest 16 days earlier than those in the control. In addition, bagging increased fruit length, diameter, weight, and pulp weight in comparison to non-bagged fruit. Moreover, the brown paper bag treatment significantly reduced pest infestation (15-fold), disease infection (12-fold) and physiological disorder (6.5-fold) compared to control. The firmness, total soluble solids, and total sugar content were found maximum with brown paper bagged fruit, while Vitamin C content was higher in control fruits. Brown paper bagged fruit exhibited the longest shelf life (12 days) as compared to the control (09 days). Bagging presented a significant effect on the color and overall expression of the fruit, although it did not influence the flavour of the fruit. In conclusion, brown paper bags can help to prevent diseases and insect infestation and improve the fruit quality of bananas.

Effect of pre-harvest fruit bagging on yield, postharvest quality and shelf life of tomato (Solanum lycopersicum L.) cv. BARI Tomato-2

Fruit bagging protects fruits from pest infestation and multiple biotic and abiotic stresses during development without reducing yield. It also can potentially improve the quality and market value of fruits. Hence, the present study aimed to determine the effect of pre-harvest fruit bagging on the yield and quality of tomato (Solanum lycopersicum) cv. BARI Tomato-2. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replications that constituted the various treatments- T0: Control (no bagging), T1: White paper bag (single layer), T2: Brown paper bag (double layer), T3: Non-woven fabric bag, and T4: Jute bag from October 2021 to March 2022. The results showed that the non-woven fabric bag had the highest fruit length (57.79 mm), diameter (57.81 mm), number of fruits plant-1 (55.9), yield (4.06 kg plant-1), vitamin C (24.63mg/ 100g-1), and lycopene content (0.12 mg g-1). The maximum insect incidence (18.41%) was recorded in control and the minimum was counted in T3 (2.17%). The highest total soluble solid (6.73%0Brix) and dry matter (8.63%) were observed in a white paper bag. The highest mean color score (6.08), firmness (26.81%), and shelf life (13 days) found in fabric bags outperformed non-bagged fruits. The fabric bag showed maximum net income (21.12 TK) and the highest benefit: cost ratio (2.36). Thus, the fabric bag was the best for improving the physical and chemical qualities of tomatoes (Solanum lycopersicum) among the various fruit-covering materials.

THE INFLUENCE OF PRE-HARVEST TREATMENTS ON FRUITS QUALITY OF APPLE CULTIVARS (MALUS DOMESTICA BORKH.)

Apples fruit quality is mainly influenced by biotic and abiotic factors. Various possible pomological approaches are able to improve fruit quality and market value. Among these, techniques of fruit bagging and summer pruning have become an integral part of pomological practises in many countries, because it is a safe and eco-friendly technique to protect fruits from multiple stresses, preserving or improving the overall quality. The bagging consists essentially of enclosing a young fruit in a cardboard bag. Isolating the fruit from the external environment protects it during development from mechanical or biotic damage, especially in regions where fruits are prone to attacks by fungi, bacteria, insects and even birds. The expected increasing fruit skin color in comparison to non-bagged fruits can therefore correspond either to a reduction or an increase in color or even a greater homogeneity of the color itself.
 The aim of this research was to determine how the application of post-harvest aids affects the quality of fruits and storage capacity of three cultivars of late-ripening apples (Breaburn, Fuji and Pink Lady). Applying summer pruning and covering apple fruits with cardboard bags has a positive effect on increasing the surface of the complementary color on the skin of the fruit.In addition, the influence of these measures on the physical and chemical properties of the fruits after harvest and storage for a period of four months was examined. The experiment was set up in 2019 in a completely randomized design with five replications in the nine leaves old orchards of the Faculty of Agriculture in Belgrade. The used pre-harvest treatments influenced the increase in yield, fruit firmness, and chemical composition. The summer pruning of branches four weeks before harvesting significantly improve percentage of fruit skin color to all examined cultivars, while bagging of fruits only had increased of fruit skin to cultivar Breaburn. 

On-Tree Fruit Bagging and Cold Storage Maintain the Postharvest Quality of Mango Fruit

The present study investigates the influence of on-tree fruit bagging on the quality and shelf life of mango (Mangifera indica L. cv. ‘Samar Bahisht Chaunsa’) during cold storage (12 °C ± 1; 85–90% RH) for 0, 10 and 20 days (d) and subsequent shelf storage under ambient conditions (25 °C ± 1; 60–65% RH). Fruits were covered with brown paper bags at the marble stage and then harvested at commercial maturity. Results showed that 0 d and 10 d cold-stored fruits, irrespective of bagging treatments, retained eatable quality and shelf-life up to 7 d and 5 d during ambient storage, respectively. However, bagged fruits had better postharvest performance compared with non-bagged fruits by exhibiting slower weight loss, higher fruit firmness, more total soluble solids, vitamin C and total phenolic content and higher activities of catalase and superoxide dismutase during cold storage and ambient shelf storage. On the other hand, 20 d cold-stored fruits, both bagged and non-bagged, were decayed when kept under ambient conditions. It is proposed that mango fruit bagging could be a potential cultural practice to preserve postharvest quality up to 10 d of cold storage, followed by 5 d under ambient conditions.

Physiological Characteristics of Sunburn Peel after Apple Debagged.

The bagging of fruits provides efficient protection from high-intensity sunlight and improves fruit color and quality. However, bagged fruit suddenly exposed to bright light can cause sunburn and destroys the peel cell structure. In this study, fruits from ten-year-old apple trees of ‘Gala’ variety were debagged, and the effect of sunburn on fruits was divided into: (1) normal peels (BFN), (2) peels with albefaction (BFA), and (3) browning (BFB). The non-bagging fruits (NBF) were set as a control to study the physiological characteristics of apple fruits with different levels of sunburn. Our results showed that in the early stages of debagged fruits’ sunburn, the cell structure of the peel was partially destroyed, the color of the injured fruit surface turned white, and the peroxidation in the cell membrane of the peel increased. Initially, the fruit improved its photosynthetic protection ability, and the activity of antioxidants and phenolics was enhanced, to cope with external injury. However, with the increase in duration of high-intensity sunlight, the cell structure of the peel was severely damaged, and the increase in membrane peroxidation resulted in brown coloration of fruits. Under the same conditions, the photoprotection ability and antioxidant enzyme activity of non-bagged fruits showed higher levels. In conclusion, the non-bagged fruits were more adaptable to high-intensity sunlight as compared to debagged fruits.

Influence of fruit bagging technique on the morphometric and biochemical characteristics of two pomegranate varieties (Punica granatum L.)

The pomegranate tree is cultivated and its fruits consumed since ancient times. This tree is typical of the Mediterranean climate, with high thermal demands to mature properly. The main objective of this work was to study the influence of the fruit bagging technique on the morphometric and biochemical characteristics of the pomegranate fruits of two new varieties that are currently cultivated in the Southeast of Spain. The results indicated that the fruit bagging presented a significant effect on the weight, equatorial diameter, height and shape of the fruit, however, it did not show any influence on the peel thickness. No significant differences have been observed in the number of healthy fruits with and without bagging, however, the number of cracked fruits with Cryptoblabes gnidiella damage was higher for the non-bagged fruits. The fruit bagging presented a significant effect on the total soluble solids, maturity index, glucose, α-punicalagin, α + β-punicalagin and ellagic acid, but it did not show influence on pH, acidity, ABTS, DPPH, FRAP, total phenols, fructose, citric, malic, and quinic acid, β-punicalagin and anthocyanins. The internal fruit color was not affected by the bagging, although it did affect the external color of the fruit, and unevenly depending on the variety. Based on the results, it can be said that bagging can improve the quality of the fruit by reducing damage from pests and pathophysiology, and this benefit compensates or even exceeds the negative effects of bagging on peel color.

Quality of guava fruits bagged with different materials in an organic system

This study aimed to evaluate the interference of bagging materials on the incidence of insect larvae and the physical and chemical quality of the guava cv. Paluma in an organic system. The experimental design was in randomized blocks with seven treatments and four replications of 25 fruits each. The bagging materials (treatments) were: nonwoven fabric (TNT), transparent plastic bag, white plastic bag, parchment paper, kraft paper, and non-bagged fruits (control). The titratable acidity (TA), ascorbic acid, soluble solids (SS), SS/TA ratio, fresh mass, fruit diameter, fruit length, appearance, and fruit fly incidence were evaluated. Fruit bagging increased the fresh fruit mass, except the tulle bag, which did not change fruit diameter but increased fruit length. There was a high incidence of fruit flies in the non-bagged fruits (100%) and in those with tulle bags (56.53%), reduced to 2.15% when using parchment paper, and reaching the absence of bored fruits when using nonwoven fabric, transparent plastic, and white plastic bags, materials that provided the highest percentages of marketable fruits. All bagging materials did not change the total titratable acidity content and the SS/TA ratio; however, all of them reduced the content of total soluble solids, except the tulle bag. Fruit bagging with nonwoven fabric and parchment paper increased the content of ascorbic acid. Fruit bagging with parchment paper, plastic bag, and nonwoven fabric are efficient in the organic production of guavas for preventing the infection by insect larvae and maintaining the physical and chemical quality of the fruit.

Fruit bagging for improving quality of rainy season guava under Punjab conditions

The rainy season crop of guava is severely infested by fruit fly and fetches lower economic returns. The farmers going in for rainy season crop have to use aggressive chemical measures, which may render serious health hazard to the consumers. In the present study, different bagging materials for guava fruits viz. non-woven bags of green, white, red and blue colour, leno bags, butter paper bags, perforated polythene bags and newspaper bags were put on immature green fruits at marble stage of development and evaluated for their efficacy to prevent fruit fly damage. The fruit size, weight, organoleptic rating and yield improved significantly in all the non-woven bagged fruits as compared to non-bagged fruits. The fruit bagging especially in non-woven bags eliminated the incidence of fruit fly infestation. Thus, 98–99 per cent fruits bagged in non-woven bags were healthy, free of fruit fly infestation and marketable while non-bagged fruits exhibited 100 per cent damage. Though, the effective yield obtained from blue and white non-woven bagged treatments was <12 kg but the white coloured bags proved to be the best in terms of fruit size, yield and quality. The benefit cost (B: C) ratio exhibited by newspaper bags was highest (2.11) because they were cheaper but were not very effective in controlling the fruit fly damage. The overall costs of the bagging treatments with non-woven white bags amounted to Rs 120 per 100 fruits which is affordable as the benefits are greater compared to non-bagged fruits which were unmarketable.

Chilling Prevention on Banana ‘Nanica’ in the Field with Bagging

Low temperature in the field causes chilling injury (CI) in banana and peel browning. The aim of this paper was to investigate the influence of different bagging materials and combinations on bunch development of banana (Musa AAA cv. Nanica) and the occurrence of CI. The study was carried in Jacupiranga, São Paulo, Brazil, in a completely randomized design in 2 × 9 factorial, two years of formation (2013 and 2014) and nine bagging materials, with eight replicates. Materials consisted in blue transparent polyethylene, white non-woven fabric, white opaque polyethylene, bubble wrap, white laminated non-woven fabric, double paper, blue transparent polyethylene plus kraft paper, blue transparent polyethylene plus white non-woven fabric and control (non-bagged). Fruits formed in both years showed low L* and C* values related to the CI index. On the coldest days of 2013 and 2014, bagging raised the temperature by only 1.91 and 3.17 °C, respectively. Depending on the year of bunch formation, the bagging materials influenced the period between flowering and harvest, but not the bunch mass. In the green fruit, the content of chlorophylls was lower in double paper, while L* was higher, but there were no differences in the content of phenols for the different materials. In mature fruits, CI index, L* and a* were not affected by the bagging materials, unlike coordinates b*, h° and C*, which were lower for double paper, with no difference between other materials and non-bagged fruits. Bagging materials did not prevent CI and did not reduce the peel browning intensity.

Effect of Debagging Time on Pigment Patterns in the Peel and Sugar and Organic Acid Contents in the Pulp of 'Golden Delicious' and 'Qinguan' Apple Fruit at Mid and Late Stages of Development.

This study examined the effect of debagging time on color and flavor / taste compounds in the non-red apple cultivar ‘Golden Delicious’ and red cultivar ‘Qinguan’ at mid and late stages of fruit development. Debagging briefly improved the red color in both cultivars, the peel of ‘Golden Delicious’ presenting pale-pink hue. However, rapid anthocyanin accumulation occurred in apple peel at a specific time (after 179 days after flowering (DAF) in ‘Qinguan’) and was unaltered by debagging time in the red cultivar ‘Qinguan’. Furthermore, untimely debagging had a detrimental effect on the content of anthocyanin. All sugars increased and organic acids decreased in apple pulp at mid to late stages of development. Bagging treatment reduced the content of most sugars and organic acids, as well as, the overall total. However, glucose and citric acid contents were higher in bagged fruit than non-bagged fruit; the maximum occurred in T7 treatment that was no-debagging at DAF 159 / 196 (‘Golden delicious’ / ‘Qinguan’), i.e., 24.35 and 0.07 mg g-1 FW in ‘Golden delicious’, and 38.86 and 0.06 mg g-1 FW in ‘Qinguan’, respectively. In a word, bagging treatment can alter the pattern of peel color development in apple fruit; however, it remains difficult to alter the timing of rapid anthocyanin accumulation as it is regulated solely by development. Moreover, bagging treatment reduced the total accumulation of sugars and organic acids, and even the over total in pulp, but increased the glucose and citric acid contents in apple pulp.

Effect of Pre-Harvest Bagging on Fruit Quality of Litchi(Litchi ChinensisSonn) CV. Rose Scented

An experiment on pre-harvest bagging of litchi fruits was conducted at Department of Horticulture Govind Ballabh Pant University of Agriculture and Technology, Pantnagar. Litchi fruits cv. Rose Scented were bagged by perforated transparent polyethylene bag, green polyethylene bag, white polyethylene bag, yellow polyethylene bag, black polyethylene bag, blue polyethylene bag, butter paper bag and brown paper bag, whereas, non-bagged fruit was used as control. Fruits were bagged two months prior to harvest. Bagged and non-bagged (control) fruits were harvested at commercial maturity. After harvest, postharvest quality characteristics were determined such as, fruit Retention, fruit cracking, pericarp sun-burn, weight and size of whole fruit, total soluble solids (TSS), titratable acidity, ascorbic acid, sugar content and sensory evaluation. Results showed that brown paper bag and butter paper bag were found effective in increasing days to maturity, fruit retention, reducing fruit cracking, pericarp sun-burn as well as showed maximum fruit weight and size. Minimum acidity (0.51%) while TSS (19.5o B), ascorbic acid (21.56 mg/100gm), reducing sugar (11.31%) and total sugar (13.13%) were found maximum in fruits bagged in green polyethylene bag. Hence, brown and butter paper bags and green polyethylene bag were found effecive in improving fruit colour and maintaining fruit quality at harvest.

Effects of bagging on fruit characteristics and physical fruit protection in red pitaya (Hylocereus spp.)

The effects of bagging on fruit characteristics and its role in physical fruit protection were investigated in three pitaya cultivars: Vietnam White (VN-White) and Chuchi Liu (Hylocereus undatus), and Chaozou 5 (Hylocereus sp.). The experiment comprised four treatments: paper-white bag (P-WB), net screen-black bag, polyethylene plastic-black bag (PP-BB), polyethylene plastic-white bag (PP-WB) and non-bagged control. Fruit bagging did not change the fruit lightness but significantly affected other peel colorimetric parameters. VN-White fruits bagged with P-WB became redder (a* = 27.6), less yellow (b* = 4.4) and had higher colour purity (h° = 10.7) than non-bagged fruits. Fruits with P-WB in Chuchi Liu also showed significant difference in b* and h° values as compared with control. Bagging with PP-BB or PP-WB in Chaozou 5 also produced redder fruits (a* = 31.7 and 30.3) with more colour intensity (C* = 32.4 and 31.3) than non-bagged fruits. There were no significant differences in fruit size and weight, total soluble solids content and fruit ripening duration among treatments in all three cultivars. Fruit firmness also exhibited no significant differences among most treatments except for PP-BB, which gave a lower value than other treatments. In general, fruit bagging could reduce the peel thickness but could not increase the edible fruit rate. The most important role of fruit bagging was to effectively protect fruits from physiological factors such as cracking, bird damage and blemish, which led to the significant decrease of the total damaged and defective fruits (13.7–33.3%), as compared with non-bagged control (66.7–72.6%).

Reduced late-season leaf potassium and phosphorus levels influence decreases in sugar contents of bagged apple fruit

Fruit bagging has been widely used in the fruit production industry; however, in apples, it is known to cause a significant decrease in fruit sugar contents. To address this issue and identify the changes in leaf mineral contents associated with fruit sugar levels in bagged apples, aqueous solutions of 10 g L−1 CaCl2, 5 g L−1 KH2PO4, or 2 g L−1 Na2B4O7·10H2O were foliar sprayed during four fruit developmental stages. The late-season leaf phosphorus (P) and potassium (K) contents after the rapid fruit growth period and the soluble sugar contents in ripening fruit were significantly lower in bagged fruit than in non-bagged fruit (11.1–15.09 %). The decreases in leaf P and K contents caused by bagging were almost completely compensated for by foliage applications of CaCl2, KH2PO4, or Na2B4O7 during the fruit set period. Therefore, the fruit soluble sugar contents were significantly higher in bagged ripening fruit with foliar spray than in bagged fruit without foliar sprays, reaching the levels of non-bagged apples. The decrease in the sugar contents of bagged apples was closely associated with the decrease in late-season leaf P and K levels caused by fruit bagging.

Effects of TiO₂ and Kaolin Application on Postharvest Fruit Quality, Phenolic Compound, and Foliar Scab of Asian Pears

This study was conducted to investigate effects of TiO2 and Kaolin application on fruit quality, phenolic compound, and foliar scab incidence of four Asian pear cultivars (Pyrus pyrifolia Nakaii) ‘Hosui’, ‘Hwangkeumbae’, ‘Niitaka’, and ‘Kamcheonbae’. Non-bagged fruits were treated with foliar application of 1.0% TiO2 or 10% Kaolin, while on conventional tree fruits were enclosed in doublelayered paper bags. Conventional trees had higher average fruit weight than those treated with TiO2 or Kaolin, but the total fruit weight was higher for both TiO2 and Kaolin applications due to the increased fruit numbers. ‘Hosui’ and ‘Kamcheonbae’ fruits had higher soluble solids contents for conventional trees than those treated with TiO2 or Kaolin. TiO2 application increased fruit firmness of ‘Hwangkeumbae’ and ‘Kamcheonbae’, which was also slightly increased by Kaolin application compared to conventional fruits. Conventional fruits had bright skin color but reduced total polyphenols amongst all fruit cultivar compared to those of TiO2 or Kaolin application. The scab incidence of ‘Hosui’, ‘Hwangkeumbae’, and ‘Niitaka’ was suppressed on conventional trees, while scab was completely prevented by the TiO2 application on ‘Kamcheonbae’.

Pre-harvest fruit bagging influences fruit color and quality of apple cv. Delicious

An attempt was made to observe the effect of pre-harvest bagging with spun-bound fabric bags on color and quality of Delicious apple. Bagging was done about a month before harvesting and removed 3-day before harvesting. Bagged and non-bagged fruits were stored at 2℃ ± 1℃ and 90%-95% RH. Observations were recorded on color and fruit quality attributes such as total phenolics, AOX activity, fruit Ca contents, LOX activity, SSC and ascorbic acid contents at harvest and during storage. Our studies have revealed that bagged fruits have better color development (Hunter “a” = 52) than non-bagged fruits at harvest (Hunter “a” = 38), which declined slightly during storage. Similarly, at harvest, bagged fruits contained high amounts of Ca (5.38 mg/100g) and total phenolics (9.3 mg GAE/100gpulp) exhibited higher AOX activity (12.6 μmoles Trolox g-1), and had better SSC and ascorbic acid contents than non-bagged fruits, and there was a decline in all recorded parameters during storage. Bagged fruits exhibited lower LOX activity (1.38 μmoles min-1 g-1 FW) at harvest than non-bagged fruits (2.14 μmoles min-1 g-1 FW), indicating that non-bagged fruits were more senescent than bagged fruits. Further, LOX activity increased during storage both in bagged and non-bagged apples but increase in LOX activity was slower in bagged apples than in non-bagged apples.

Native bees pollinate tomato flowers and increase fruit production

The tomato plant has a specific relationship with native pollinators because the form of its flowers is adapted to buzz pollination carried out by some pollen-gatherer bees that vibrate their indirect flight muscles to obtain that floral resource. The absence and the low density of these bees in tomato fields can lead to pollination deficits for crop. The aim of this study is to demonstrate that open tomato flowers, probably visited by native pollinator, have greater pollen load on their stigma than unvisited flowers. Another objective is to show that this great pollen load increases fruit production. We selected crops of the Italian tomato cultivar in areas of the State of Goiás, Brazil. Thirty seven plants of three crops each had one inflorescence bagged in the field. Bagged and non-bagged flowers had their stigmas collected and the amount of pollen on their surfaces was quantified. For the comparison of fruit production, we monitored bagged and not-bagged inflorescences and after 40 days, their fruits were counted, weighed, measured and had their seeds counted. The amount of pollen grains on the stigma of flowers available to pollinators was higher than that on the stigma of bagged flowers. On average, fruit production was larger in not-bagged inflorescences than in bagged inflorescences. In addition, not-bagged flowers produced heavier fruits than did bagged flowers. There was a significant difference in the number of seeds between treatments, with significantly more seeds in the non-bagged fruit. Our results show that native bees buzz-pollinate tomato flowers, increasing the pollen load on their stigma and consequently fruit production and quality.

Efficacy of some biodegradable films as pre-harvest covering material for guava

To produce guavas with good commercial or industrial potential, fruit farmers use phytosanitary practices such as fruit bagging. Bagging protects the fruit mainly from the attack of pests, such as the fruit fly ( Anastrepha spp.) and the guava weevil ( Conotrachelus psidii), and reduces the use of insecticides and fungicides. This investigation aimed to develop and produce biodegradable films from cassava starch and poly(butylene adipate-co-terephthalate) (PBAT) by extrusion for application in pre-harvest guava fruit bagging. After the fruit harvest, for 6–9 weeks all films were more fragile and rigid, but did not present cracks. BF70 was the most fragile and had the greatest tendency to tear; however, it remained whole until harvesting. Fruit bagged with films BF30, BF50, BF70 was analyzed for fruit quality and compared with PSF control and non-bagged fruit. There was no difference between the treatments relative to physical and chemical characteristics, indicating that biodegradable film did not influence fruit development when compared to the PSF control.

INFLUENCE OF INDUCED RIPENING AND COLD STORAGE PROTOCOLS ON THE INCIDENCE OF POSTHARVEST DISEASES OF DATE PALM FRUIT

Date palm (Phoenix dactylifera L.) is a crop of increasing importance in the Elx area (Southeast of Spain). Since in this area date fruit are commercialized for fresh consumption, the most important problems limiting their storability are irregular ripening, weight loss, and postharvest decay. Postharvest treatments to uniformly accelerate fruit ripening and avoid more than one harvest are economically mandatory for the most important date cultivars in the area. In this work, the incidence of major postharvest diseases was determined for two consecutive seasons on locally grown ‘Hayani’ and ‘Medjool’ dates sealed in multi-layer PE bags and cold-stored (CS) at -3°C for up to 3 months before or after exposure of non-bagged fruit to induced ripening treatments of 98% CO2 at 25°C for 2 or 4 days (CO2) or air at 25°C for 2 or 4 days (Heat). Determinations were performed after shelf-life of 10 days in an ambient air atmosphere at 20°C. Fungal pathogenic isolates were plated in PDA Petri dishes and incubated at 25°C for further macroscopic and/or microscopic identification. Irrespective of the protocol, all ‘Hayani’ dates exposed to CS, CO2+CS, and Heat+CS were infected by Penicillium spp. Although with variable incidence depending on the season, other frequent disease causal agents were Aspergillus niger, Alternaria spp., and Cladosporium spp., generally in this order. A. niger and Alternaria spp. were significantly less frequent on Heat+CS and CO2+CS-treated dates, respectively. On ‘Medjool’ dates, Penicillium spp. and A. niger were isolated from about 100 and 10%, respectively, of fruit treated with either CS+CO2 or CO2+CS. Severe microbial fermentation was observed on dates exposed to the sequence CS+Heat.

Effects of Bagging on Volatiles and Polyphenols in “Wanmi” Peaches during Endocarp Hardening and Final Fruit Rapid Growth Stages

Fruits of the late-ripening peach cultivar "Wanmi" were bagged at the early period of fruit endocarp hardening, and the bags were removed 1 wk before maturity harvest. The effects of bagging on volatile compounds and polyphenols were studied. Total volatiles and the sum of C(6) compounds, esters from bagged fruits were significantly lower than from nonbagged fruits from the beginning of the final rapid fruit growth stage to maturity. As the most dominant compounds of C(6) compounds and esters, the lower contents of hexanal, trans-2-hexenal, hexyl acetate, cis-3-hexenyl acetate, and trans-2-hexenyl acetate attributed to the lower content of C(6) compounds and esters in bagged fruit. γ-Hexalactone and δ-decalactone were produced earlier in bagged fruits than in nonbagged ones, suggesting that bagging accelerates fruit maturity. Level of γ-decalactone in bagged fruits was significantly lower than in nonbagged fruits at 159 days after full blossom (DAFB), so did δ-decalactone at 166 DAFB. Bagging did not affect chlorogenic acid and catechol contents of either fruit peel or flesh, nor did it affect contents of keracyanin or quercetin-3-rutinoside in fruit flesh during fruit development. However, keracyanin and quercetin-3-rutinoside levels were significantly reduced in bagged fruit peels before ripening compared to nonbagged fruit peels. Considering the large changes in volatiles and polyphenols, the key stage for "Wanmi" fruit maturity was between 126 DAFB and 147 DAFB, about 1 mo ahead of maturity.