Improving blueberry cold storage quality: the effect of preharvest hexanal application on chilling injuries and antioxidant defense mechanisms.

Blueberries are vulnerable to chilling injury (CI). This can lead to limited longevity when they are subjected to cold storage conditions. This study investigated the effectiveness of a preharvest spray containing 0.02% hexanal in reducing CI and improving the postharvest storage quality of 'Star' and 'Biloxi' blueberries. The blueberries were stored for a period of 5 weeks at 2 °C and in 90% relative humidity (RH). The findings revealed that the preharvest hexanal spraying of both cultivars delayed senescence by mitigating CI, as evidenced by the bolstering of the antioxidant defense system through increased superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), catalase (CAT), and phenylalanine ammonia lyase (PAL) enzyme activity. The treated fruit also maintained elevated levels of total phenol content (TPC), total flavonoids (TFC), and vitamin C, demonstrating enhanced free radical scavenging capacity (FRSC), while exhibiting reduced polyphenoloxidase (PPO) activity, and reduced malondialdehyde (MDA), and H2O2 content in comparison with the control group. The preharvest hexanal treatment also suppressed fruit softening by maintaining greater firmness and higher membrane stability index (MSI) scores, inhibiting the activity of polygalacturonase (PG), pectinmethylesterase (PME), xylanase, and α-amylase, and reducing microbial counts (MC) and incidence of decay (DI) in comparison with the control. Preharvest hexanal treatment also improved the overall storage quality by reducing weight loss, total soluble solids (TSS), pH, and the TSS/acid ratio, while increasing titratable acidity (TA) in comparison with the control during cold storage. The findings suggest that hexanal, as a preharvest application, delays senescence effectively and preserves overall quality by enhancing cold tolerance through antioxidant defense mechanisms in blueberry storage under cold conditions. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Postharvest hexanal application delays senescence and maintains quality in persimmon fruit during low-temperature storage.

BACKGROUND: Persimmon (Diospyros kaki L.) fruit is characterized by rapid metabolic changes following ripening, and softening occurs due to the gradual breakdown of the cell membrane by direct catabolic cascades of phospholipase D enzyme on the phospholipid bilayer. Cell membrane weakening is also enhanced by the generation of reactive oxygen species during stress conditions such as cold storage and postharvest handling. This research evaluated the postharvest hexanal dipping application on persimmon fruit storage quality. RESULTS: The response of 'MKÜ Harbiye' persimmon fruit to exogenous hexanal at different concentrations (0.04% and 0.08%, named as HEX-I and HEX-II, respectively) on quality parameters, chilling injury (CI), microbial growth, antioxidant compounds and free radical scavenging capacity (FRSC) during storage at 0 °C and 80-90 ± 5% relative humidity for 120 days were evaluated. Both hexanal treatments retained quality and delayed senescence, as indicated by greener peel (lower a* and L* values), higher firmness, total phenol concentration, FRSC and titratable acidity, but lower weight loss, electrical conductivity, rate of CO2 , ethylene production, decay and microbial growth than the control. Total soluble solids were lower in treated fruit than the control up to 100 days, and were much lower in HEX-I treatment as compared to HEX-II treatment. HEX-I treatment exhibited lower CI than the other treatments during storage. CONCLUSION: Hexanal at 0.04% could be used to increase the storage period of 'MKÜ Harbiye' persimmon fruit up to 120 days at 0 °C and 80-90 ± 5% relative humidity by retaining quality and delaying senescence. © 2023 Society of Chemical Industry.

Effects of calcium chloride plus coating in modified-atmosphere packaging storage on whole-radish postharvest quality.

BACKGROUND: Calcium treatment plays an important role in regulative physiological functions in fruits and vegetables after harvest that is protected many horticulture products postharvest quality during storage life. The effects of 2% calcium chloride (CaCl2 ) and 1% starch + 2% glycerin on the physiological, biochemical, and quality responses of the Kadirli radish variety were investigated. RESULTS: Whole leafless radishes were stored in 10 kg modified-atmosphere packages at 90% relative humidity conditions at 4 °C for 56 days. Significant differences were observed in radish treated with 2% CaCl2 and coating with 1% starch + 2% glycerin compared with the control. There were significant effects of the application of CaCl2 either alone or in combination with a coating on radish with regard to the firmness and the important physiological disorder of hollowing ratio percentage and cell membrane (malondialdehyde) aging level of the fresh whole radish. CONCLUSION: The application of CaCl2 alone and in combination with coating protected the physical, chemical, and microbiological quality characteristics of radish and prolonged the shelf-life quality of fresh radish. © 2020 Society of Chemical Industry.

SNP Discovery by GBS in Olive and the Construction of a High-Density Genetic Linkage Map.

Genetic linkage maps are valuable tools for genetic, genomic, and crop breeding studies. Several genetic linkage maps were constructed for the olive (Olea europaea L.) genome, mainly using amplified fragment length polymorphisms (AFLPs) and simple sequence repeat (SSR) markers. However, AFLPs and SSR markers were not enough to develop a high-density olive linkage map. Genotyping-by-sequencing (GBS), a recently developed single-nucleotide polymorphism (SNP) identification methodology based on next-generation sequencing (NGS) technologies, has been demonstrated to be useful for the identification of a high number of SNP markers and the construction of high-density genetic linkage maps. In the present study, we identified a total of 10,941 SNPs from a cross between the olive cultivars 'Gemlik' and 'Edincik Su' using GBS and de novo SNP discovery implemented in the computer program "Stacks." A high-density genetic linkage map for the olive genome was constructed using 121 cross-pollinated full-sib F1 progeny and 5643 markers (21 SSRs, 203 AFLPs, and 5736 SNPs). This linkage map was composed of 25 linkage groups, covering 3049 cM of the olive genome, and the mean distance between the flanking markers was 0.53 cM. To the best of our knowledge, this map is the most saturated genetic linkage map in olive to date. We demonstrated that GBS is a valuable tool for the identification of thousands of SNPs for the construction of a saturated genetic linkage map in olive. The high-density genetic map developed in this study is a useful tool for locating quantitative trait loci and other economically important traits in the olive genome.

Comparison of lipids, fatty acids and volatile compounds of various kumquat species using HS/GC/MS/FID techniques.

BACKGROUND: Kumquat (Fortunella spp.) is one of the important fruit species that has been introduced into Turkey recently. It is well adapted to the Mediterranean region in Turkey. Early research of kumquat was started on adaptation and pomological traits, and only a few studies have been concerned with chemical content. After understanding the health benefits of kumquat fruits farmers started their plantations in Turkey. Thus in this study the fruits of five kumquat species - Fortunella margarita (Lour.) Swingle, F. crassifolia Swingle, F. obovata Hort. ex Tanaka, F. hindsii (Champ. ex Benth.) Swingle, and limequat [Citrus aurantifolia × F. japonica (Thumb.)] - were compared based on their lipids, fatty acids and volatile profiles. The lipids, fatty acids and volatile profiles were determined by using gas chromatography with flame ionisation detection (GC/FID) and headspace gas chromatography mass spectrometry (HS-GC/MS) techniques. Volatile constituents of kumquat fruits were isolated by a headspace method. RESULTS: The total lipid content (%) of kumquat species ranged from 0.26% to 0.37%. The polyunsaturated fatty acids were detected in a higher amount compared to the monounsaturated fatty acids and saturated fatty acids, respectively. The headspace technique led to the identification of 39 compounds and among a total of 39 constituents identified, d-limonene was the most abundant compound, comprising 67.78-88.72%. The results indicated that kumquats are rich in dietary and health benefits. CONCLUSION: Thirty-nine compounds were identified and terpenes were the major chemical group in all kumquat genotypes. Esters, alcohols, aldehydes and ketones were also detected. The present study revealed that the kumquat fruits have a valuable levels of health beneficial chemo-preventive effects and genotypes varied based on their lipid, fatty acids and volatile constituents.

The effect of oleum myrtle on the fruit quality of strawberries during MAP storage.

Strawberries are known to be significant source of the nutraceuticals; however, rapid perishable property of this fruit is very important issue. Up to now, extension of this fruit is still the focus of scientific and industrial interest in the worldwide. Therefore, of the known nutraceuticals, myrtle essential oil in this study is intended to use for extending the storage of strawberries. Strawberries were individually immersed in the treatment solutions of 0.1 % myrtle oil, 0.5 % myrtle oil and then placed in Modified Atmosphere Packaging (MAP) for 8 days at 5 °C. The control fruits without myrtle oil treatment were also placed in MAP and stored under the same condition. Treatment of myrtle oil decreased the weight and the fruit firmness loss. Furthermore, titratable acidity (TA), pH and colour value did not display significant changes during storage. Fluctuations were observed in the vitamin C, total soluble solids (TSS), TSS/TA content and microbial growth. The O2 concentration in MAP decreased from 21 % to around 15 %, whereas, CO2 concentration varied from 6.0 to 6.9 % in the treatments by the 8th day of storage time. The delay of flesh firmness, weight loss, vitamin C loss and increasing CO2 concentration in MAP, best sensory quality as well as limiting the growth of microbial parameters in concern was attained through the use of 0.5 % myrtle oil, suggesting that 0.5 % myrtle oil showed more pronounced activity than 0.1 % myrtle oil and control in maintaining the fruit quality and shelf life of fruits during MAP storage.