Commercial Maturity Stage Research Articles

Influence of Post-Harvest 1-Methylcyclopropene (1-MCP) Treatment and Refrigeration on Chemical Composition, Phenolic Profile and Antioxidant Modifications during Storage of Abate Fétel Pears.

'Abate Fétel', a winter cultivar, is the most important pear cultivar in Italy; its fruits are appreciated by consumers for their aroma, texture and balanced sweet and sour taste. Maintaining high-quality characteristics to prolong the shelf-life of fruit and preserve the sensory and nutritional quality is a priority for the food industry. The aim of our study was to test the effectiveness of 1-methylcyclopropene (1-MCP) and cold storage in prolonging the shelf-life of these fruits, which were harvested at maturity at two different times. This work focused on the effects of different storage treatments and two ripening times on (i) the chemical composition of Abate Fétel pulp fruits to preserve their sweet taste and aroma and (ii) the phenolic profile composition and antioxidant activity of the peel, which is naturally rich in phytochemicals and important for the fruit's shelf-life and in the functional food industry for its high nutritional value. Abate Fétel fruits were harvested at the optimal commercial maturity stage, first on 15 September, having been treated with 1-MCP and stored for 2 months at cold temperatures; the other fruits were harvested at the end of September and stored in a cold cell for 2 months. The fruit pulp was tested for glucose and fructose, pH, acidity and organic acids (malic, citric, fumaric and shikimic), phenolic content and phenolic compounds (chlorogenic and caffeic acids, rutin, hyperoside, kaempferol-3-rutinoside and isoquercitrin), and the antioxidant activities in the fruit peels were measured. Treating the fruits with 1-MCP better preserved the phytochemical compounds compared to simple refrigeration, preserving the fruit's quality and prolonging its shelf-life. All the treatments help to maintain the glucose and fructose content and the acidity, preserving the aroma and organoleptic characteristics.

Impact of Cold Storage Temperature and Shelf Life on Ripening Physiology, Quality Attributes, and Nutritional Value in Apricots-Implication of Cultivar.

This work aimed to investigate the storability potential of Orange Red and Orange Rubis apricots harvested at commercial maturity stage during cold storage (CS) at 1 or 5 °C for up to 28 days, followed by shelf life (SL) at 20 °C for 2 days. The variables evaluated included total soluble solids, titratable acidity, pH only at harvest, weight loss (WL), ethylene production rates, peel color, firmness, chilling injury incidence (CI), concentrations of total phenolics, flavonoids, carotenoids, total antioxidant capacity, b-carotene, b-cryptoxantine, and lutein. The main results showed that storage at 5 °C resulted in higher WL and CI symptoms than at 1 °C during both CS and SL, increased ethylene production during CS, whereas there was limited or no effect of CS temperatures on changes in firmness, color, and all antioxidants during CS. Firmness decreased abruptly soon after harvest in Orange Rubis, but progressively in the remaining samples of both cultivars during CS and SL. SL advanced fruit deterioration according to WL, CI, and softening. During SL, ethylene production increased in all samples. Orange Red exhibited higher ethylene rates during SL and antioxidant concentrations throughout CS and SL, by comparison. Conclusively, storage temperature at 1 °C retained WL, CI, and ethylene production, and both cultivars were marketable up to 21 days CS without SL or up to 14 days CS followed by SL, although Orange Rubis exhibited CI after 14 days, while Orange Red exhibited CI after 21 days of CS.

Aromatic profile of black truffle grown in Argentina: Characterization of commercial categories and alterations associated to maturation, harvesting date and orchard management practices

Black truffle (Tuber melanosporum) is one of the most appreciated fungi in the world mainly due to its aromatic properties. In the emerging markets such as Argentina, the aroma of locally produced truffles has not been described yet. The volatile organic compounds (VOCs) from 102 black truffles from Argentina were analyzed using solid phase microextraction gas chromatography coupled with mass spectrometer detector (SPME-GC-MS). Several factors such as commercial category, maturity stage, host tree, geographical origin, and aromatic defects detected during classification were also registered and considered. As a result, 79 VOCs were detected, among which 2-methyl-propanal, 2-butanone, 2-methyl-1-propanol, butanal-3-methyl, 3-methyl-1-butanol, 2-methyl-1-butanol were present in high percentage in fresh mature truffles, whereas immature truffles were associated with 3,5-dimethoxytoluene, 2-phenyl-2-butenal, 2,3-dimethoxytoluene. The Argentine black truffles showed significant similarities in their aromatic profile when compared with their Australian and European counterparts, but with some distinctive notes.

The Effect of Preharvest Application of Arginine on the Postharvest Quality of Sweet Cherry Fruits during Storage

ABSTRACT The quality of sweet cherry fruits decrease rapidly after harvest and in some cases does not reach the consumers properly due to the time require for transferring and market. Therefore, using chemical compounds is essential to increase durability and maintain its quality. This study was conducted to investigate the effects of arginine on postharvest quality of sweet cherry fruits. The sweet cherry fruits (Prunus avium L. cv TakDanehe Mashhad) were sprayed with arginine (0, 200, and 400 μM) one month before harvest. Fruits were harvested at commercial maturity stage according to acceptable color standards. After harvest, the fruits were transferred to the laboratory and immediately kept in cold storage with temperature of 1°C with 90–95% relative humidity (RH) for 20 days. The results showed that in treated fruits, electrolyte leakage, active oxygen production, and lipid peroxidation were decreased. The activity of antioxidant enzymes including ascorbate peroxidase, catalase, and superoxide dismutase was increased compared to control. The treated fruits with arginine 400 µM showed the highest enzymatic activity during cold storage. The percentage of chilling injury and fresh weight loss in treated fruits has decreased comparing control fruits. According to the results lowest amount of pH observed in fruits treated with arginine 400 µM. Arginine increased the amount of titratable acid, soluble solids, and vitamin C, as well the firmness of fruits. As short, arginine preharvest treatment at 400 µM concentration improved the postharvest quality of sweet cherry fruits.

Bioactive properties and enzymatic activities in long and round type eggplant (Solanum melongena L.): Inferences for processable traits

Eggplant is a valuable commercial vegetable widely consumed due to its unique meaty taste and nutritional and functional properties. The present investigation was done with the aim to assess the bioactive properties and enzymatic activities in twenty three different long and round type eggplant genotypes to ascertain their amenability for processable traits. The eggplants were harvested at commercial maturity stage and assessed for total phenolics content, total flavonoids, antioxidant capacity and browning related enzymatic activities (polyphenol oxidase and peroxidase). The results indicated that there were significant dissimilarities among all genotypes with regard to their functional compounds content and browning enzyme activities. The biochemical screening showed maximum phenolics content in Kashi Taru (81.1 mg gallic acid equivalent/100 g fresh weight) which was about 4.0-fold higher than IVBL-23 (19.3 mg gallic acid equivalent/100 g fresh weight). Additionally, total flavonoids content varied from 1.86 (IVBHL-UT-6 and IVBHR-18) to 5.83 mg rutin equivalent/100 g fresh weight (IVBHL-UT-1). The total antioxidant capacity among different eggplant cultivars varied by about 1.3-fold. These findings are useful for pre-breeding parental selection and assorting genotypes for higher antioxidant capacity and processable traits. About 3.5-fold variation in browning enzymatic activity clearly indicates the scope for selecting cultivars with lesser flesh browning and thus, higher suitability for processing particularly for development of products like eggplant extract, dips or dried flakes.

Reduction of chilling injury of ‘Washington’ navel orange fruits by melatonin treatments during cold storage

Abstract Cold storage is used to improve the efficiency of storage and handling of orange fruits, but the fruits are exposed to chilling injury (CI). Antioxidant enzymes are part of the antioxidant defence system against CI of ‘Washington’ oranges during cold storage, which controls storage/handling efficiency. In this study, melatonin (ME) was used on fruits to reduce cold damage. To assess the action of ME influences; fruits were picked from the tree at the commercial maturity stage and divided into two groups that were uniform in size and colour. Then, they were immersed in ME solution at 0 mmol, 10 mmol, 100 mmol or 1,000 mmol for 20 min at 20 ± 1 °C. The treated fruits were stored at 4 ± 1 °C and 95 ± 1% RH for 4 weeks during 2019 and 2020 seasons. The physical and chemical characteristics of the stored fruits were measured every week up to the end of the storage period. Results indicated that immersing fruits in 1,000 μM ME minimised the CI-index and the water loss%, while preserving the orange peel colour (h°) during cold storage. On the other hand, the same treatment caused slight changes in soluble solid content (SSC%), maintained ascorbic acid (AA) content and the stability of total acidity (TA%), enhanced the antioxidant enzymes activities (AEAs) such as ascorbate peroxidase (APX), catalase (CAT), and superoxidase dismutase (SOD) and also reduced the rate of malondialdehyde (MDA) and ion leakage (IL) during cold storage. Moreover, it minimised hydrogen peroxide (H2O2) and superoxide anion (O2 •−) production and caused pronounced results to be exhibited in antioxidant capacity. Overall, the 1,000 μM ME treatment for orange fruits afforded more tolerance against cold storage stress.

Effect of surround WP (a Kaolin-based particle film) on Ceratitis capitata infestation, quality and postharvest behavior of cactus pear fruit cv Gialla

• Medfly can cause high preharvest and postharvest losses to cactus pear • Preharvest kaolin treatments effectively prevented medfly damage • Kaolin treatments reduced postharvest losses from decay caused by fungi or bacteria • Kaolin did not negatively affect the ripening process of cactus pear • Kaolin increased the postharvest level of betaxantins and polyphenols in cactus pear A Kaolin-particle film (Surround WP) was applied at 3% to cactus pear (Opuntia ficus-indica cv Gialla) to assess its capacity to Control medfly (Ceratitis capitata Wiedemann) infestation and to evaluate its effects on the quality and postharvest behavior of treated fruit. In the first trial, Kaolin was applied at the end of July when fruit were green and about two weeks later, at color breakage. Its efficacy was compared with a standard organophosphate insecticide (Phosmet). The experiment was conducted in two locations in 2014 and 2015. Kaolin application was very effective in preventing medfly attacks until natural fruit drop in November. Kaolin treated fruit were harvested at the commercial maturity stage and stored 2 weeks at 8 °C plus 1 week at 20 °C, or 3 weeks at 2 °C plus 1 week at 20 °C. The incidence of decay in the presence of medfly larvae or only due to molds was 2 -13%. Phosmet was ineffective in preventing medfly attacks. The second study of Kaolin on fruit quality and postharvest behavior demonstrated that Kaolin slightly delayed fruit coloration when fruit was once or twice before harvest. Respiratory activity, ethylene rates, juice chemical composition and color at harvest time and after 1 or 2 weeks of storage at 8 °C plus 4 d at 20 °C demonstrated slight differences between Control fruit and Kaolin. Vitamin C, betaxantins levels and the antioxidant capacity of Kaolin treatments were lower or not different than Control fruit at harvest but increased at a higher rate than in Control fruit over storage. Total phenols decreased in all treatments during storage but at a slower rate in Kaolin treatments. Overall results show that Kaolin treatments are effective to prevent medfly attacks in cactus pears with no negative effect on fruit quality and shelf life.

ANTIOXIDANT PROPERTIES OF TOTAL LUTEIN CONTENT IN DIFFERENT PARTS OF PUMPKIN (Cucurbita maxima)

Pumpkin (Cucurbita maxima) is a vegetable crop which is commonly consumed as vegetables or incorporated into food products. Pumpkin flesh was reported abundant with carotenoid compounds includes α-carotene, β-carotene, β-cryptoxanthin, lutein and zeaxanthin. As this antioxidant related to the colour pigment, these nutrients highly potential to be in other parts of pumpkin such as peel and seed. Therefore, the aim of this was to determine the total lutein content in different parts of pumpkin and their antioxidant properties. The pumpkin would be collected and evaluated at the commercial maturity stage (60% to fully orange-yellow of fruit peel). The presence of the lutein properties using DPPH, FRAP and ABTS assays in different parts of pumpkin was tested by using microplate spectrophotometer and analysed statistically with SPSS version 20. Among of all pumpkin fruit parts, flesh presented the highest concentration of potential lutein extracts, followed by peel and seed, respectively. On the contrary, potential lutein extracts from the pumpkin peel had the highest antioxidant activity in terms of DPPH, FRAP and ABTS assays when compared to the lutein extracts in flesh and seeds. This study indicates that the potential lutein from Cucurbita maxima especially peel may be the alternative to be used as both natural antioxidants in food products due to increasing demand for natural food preservatives. Therefore, this study may act as a source for others to further study to optimize the usage of pumpkin by-products.

Dissection of the incidence and severity of purple spot physiological disorder in loquat fruit through a physiological and molecular approach

Loquat (Eriobotrya japonica) fruit marketability is affected by the incidence and severity of purple spot (PS), a pre-harvest physiological disorder showing an evident skin discoloration with depressed surface. Despite its impact in limiting the cultivation and economic potential of loquat, the etiology of this disorder is still poorly understood. To this end, our study aimed to investigate and disclose possible mechanisms underlying PS development. The intensity and severity of PS in three loquat cultivars (‘Morphitiki’, ‘Karantoki’ and ‘Obusa’) was phenotypically monitored during successive on-tree fruit developmental stages. ‘Obusa’ fruits harvested at commercial maturity stage showed the highest incidence of purple spot (58.6%), while ‘Morphitiki’ fruits did not show any symptoms. ‘Karantoki’ fruits demonstrated an intermediate response, with 31.3% of the fruit being affected. Thereafter, fruits with 30–50% PS severity were selected and used for further analysis; peel tissue was removed from both symptomatic and asymptomatic tissue of the same fruit for all examined cultivars. ‘Karantoki’ fruit with PS were characterized by the highest accumulation of total soluble sugars, sucrose, glucose and fructose contents, while the concentration of these primary metabolites was the lowest in asymptomatic fruit of ‘Obusa’, exception made for the sucrose. The incidence of PS was also transcriptionally investigated by assessing the mRNA profile of important genes involved in polyphenolic (PAL1, PAL2 and PPO1) and carbohydrate (CWI2, CWI3, SPS1, SPS2, NI2, NI3, SuSy, HXK, FRK and VI) pathway. The enhanced expression levels of CWI3 and VI genes in symptomatic fruit of the highly susceptible cultivar ‘Obusa’ highlight a cultivar-specific type of response. Notably, SuSy registered significantly suppressed levels in symptomatic tissue of both ‘Obusa’ and ‘Karantoki’. To what extent PPO is associated with PS incidence and whether the etiology of the disorder can be assigned to an oxidative process triggered and coordinated by its action need to be further elucidated. The aforementioned genes are suggested to be further examined as potential markers towards a more sophisticated and informed characterization of purple spot detection in loquat fruit.

Antioxidant Activity and Phenol Content in Different Tissues of Stone Fruits at Thinning and at Commercial Maturity Stages

Fruits and their by-products are a font of polyphenols and antioxidant compounds which are heterogeneously distributed in the different tissues. These by-products include thinned fruits that contains large amounts of bioactive compounds. The present study aims to determine changes in antioxidant activity and polyphenols in different tissues (peel, flesh and seed) of five stone fruits (apricot, peach, flat peach, nectarine and plum) at thinning and at commercial maturity stage. The phenol and flavonoid contents decreased from thinning to harvest for peel and flesh (up to 95%). Hydroxycinnamic acids, mainly neochlorogenic and chlorogenic, were the predominant groups of phenols in both maturity stages, thinning and commercial. The seeds were the tissues with the highest antioxidant capacity, particularly the flat peach seed in both maturity stages. Thus, thinned stone fruit extracts might be used as a source of beneficial compounds. Also, seeds of some fruits at commercial maturity, a by-product of juice and jam industries, could be a promising source of bioactive antioxidants.

Postharvest 1-methylcyclopropene treatments maintain the quality of Rosa sterilis D. shi during storage

Abstract Effects of different concentrations of aqueous 1-methylcyclopropene (1-MCP) on Rosa sterilis D. shi fruits were investigated. The fruits were harvested at commercial maturity stage and treated with 1-MCP treatment at 0.5, 1.0, and 1.5 μL L-1 for 20 h at 25 °C in an air tight chamber along with control sample to evaluate the effect of 1-MCP concentration on its quality during storage. The result showed that postharvest treatment with 1.0 μL L-1 1-MCP suppressed the respiration rate, ethylene production rate and POD activity in Rosa sterilis D. shi fruits, inhibited the transport of reducing sugar and the increase of cellulose, delayed the increase in PPO activity, and retarded the decrease in ascorbic acid. The regulation of fibrosis process with postharvest 1.0 μL L-11-MCP treatment could be used to maintain the quality of Rosa sterilis D. shi fruits.

Postharvest flavonol and anthocyanin accumulation in three apple cultivars in response to blue-light-emitting diode light

The effects of postharvest blue-light irradiation on the accumulation of anthocyanins and other phenolic compounds, and on phenylalanine ammonia-lyase activities and color development in the skin was investigated in fruit of three apple cultivars (Malus domestica Borkh.). ‘Idared’, ‘Fuji’, and ‘Carjevič’ apples were harvested at the commercial maturity stage and irradiated or not with blue LEDs (peak wavelength 444 nm) at 8 °C for 7 days. Response to the irradiation was cultivar dependent. Anthocyanin accumulation was greatest in ‘Idared’ apples; however, the anthocyanins profile differed from that in the naturally colored apples. Twelve phenolic compounds were evaluated. Among these, chlorogenic acid and total flavonols increased in all cultivars after blue-light irradiation. Structure-specific responses of quercetin glycosides were detected in terms of the sugar moieties. Three out of six evaluated quercetin glycosides increased after irradiation, with the highest relative increase seen for quercetin 3-O-arabinopyranoside, followed by quercetin 3-O-galactoside and quercetin 3-O-glucoside. Contents of quercetin 3-O-arabinofuranoside, quercetin 3-O-rhamnoside and quercetin 3-O-xyloside were not affected by irradiation. The highest phenylalanine ammonia-lyase activity was seen for ‘Fuji’ apples after blue-light irradiation. Therefore, blue-light irradiation appears to be promising to enhance color and nutritional quality of apples.

Tolerance of ‘Baladi’ mandarin fruits to cold storage by postharvest pectin/PVA blend with ascorbic acid treatment

Postharvest chilling injury (CI) of 'Baladi' mandarin is related to the activity of antioxidant enzyme activities (AEAs) during cold storage. The performance of pectin/polyvinyl-alcohol (PC/PVA) blending in ascorbic acid (AA) to increase storability tolerance of mandarin fruit under cold otherwise the impacts of PC/PVP-AA on antioxidant enzymes were assessed. The mandarins were harvested manually from trees aged-8-years on April 15th when the fruits reached commercial maturity stage. Fruit were coated with PC/PVA biopolymer with AA at the different concentration (0, 3, 6 and 9 mM). The experiment was conducted during two growth seasons (2017–2018). Fruits coated by PC/PVA-AA for 20 min and stored at low temperature (4 ± 1 °C and 95 ± 1% RH) for 60 days. The studies were distinguished within a pair of groups: physical and chemical assessments. The physical measurements chilling injury index (CI-index), weight loss%, and mandarin peel color profile (lightness, Chroma, Hue) were monitored. However, the chemical analysis for instance soluble solid content (SSC%), titratable acidity (TA%), SSC/TA-ratio, for evaluating mandarin fruit maturity were estimated. The AEAs were evaluated: ascorbate peroxidase (APX), catalase (CAT), granulation reductase (GR), and superoxide dismutase (SOD). Plus, malondialdehyde (MDA), and cell membrane ion leakage (IL%) were considered. Further, the O2 and H2O2 production rate were measured beside the scavenging activity and inhibition (DPPH and ABTs). Results indicate that the coated mandarin by PC/PVA-AA 9 mM exhibited less CI. Also, it forced AEAs in activities much more compared to other treatments. Moreover, it reduced the formation of O2•̶ radical and H2O2 and more scavenging activities (DPPH and ABTs) during cold storage. Therefore, the coating treatment PC/PVA-AA 9 mM for mandarin fruits provided more tolerant to cold storage stress.

UV-C treatment promotes quality of early ripening apple fruit by regulating malate metabolizing genes during postharvest storage.

Early ripening apples are usually used for fresh marketing because of short storage life, although they are with high acid and low sugar contents. Understanding the malate metabolism in fleshy fruit and underpinning process during ripening is crucial for particular crop improvement where acidity is a concern for direct consumption or further processing. In this research, a traditional Chinese apple cultivar ‘Hongyu’, which belongs to early ripening apple cultivar, were freshly harvested at commercial maturity stage (120 Days after full bloom) and used for different storage temperature (4°C, 20°C) and UV-C treatment (following storage at 20°C after treatment). Simple sugars (glucose, sucrose, and fructose) and organic acids (malic, and oxalic) were assessed after 14 d of storage. Compared to fruits stored at 20°C, the malate content in fruits stored at 4°C significantly higher, while it was decreased significantly in UV-C treated fruits stored at 20°C after 14 d of storage. The sugar content was almost similar throughout the UV-C-treated fruits and fruits stored at different temperature. The higher ratios of total sugars to total organic acids in UV-C treated fruits after 14 d suggest that UV-C treatment has the potential to improve the taste of early ripening apple cultivars. Considering the significant difference in malate the samples at 14 d of storage were subjected for RNA-seq analysis. Transcriptome analysis revealed that the phenomena underlying this change were governed by metabolism of malate by the regulation of NADP-malic enzyme (NADP-ME) and phosphoenolpyruvate carboxylase kinase (PEPCK) in apple during postharvest storage. This transcriptome profiling results have specified the transcript regulation of malate metabolism and lead to possible taste improvement without affecting the other fruit quality attributes.

Preliminary physicochemical and sensory characterization of new “Picota”-type cherry cultivars (Prunus avium L.)

The Jerte Valley (Extremadura, Spain) has been clearly distinguished for the cultivation of traditional sweet cherry landraces (mainly ‘Ambrunes’, ‘Pico Negro’ and ‘Pico Colorado’), which are generally known as “Picota”-type cherries because they are usually harvested stemless. Additionally, these cultivars are included into the Protected Designation of Origin “Cereza del Jerte”. These autochthonous “Picotas” are highly appreciated in European markets, especially in England, because of their outstanding organoleptic characteristics. Notwithstanding, several technical problems restrict the sustainability of “Picota”, mainly small fruit size and self-incompatibility. In this work, thirteen new selections “Picota”-type obtained from the Sweet Cherry Breeding Program of CICYTEX were evaluated in one harvest season (2016), concerning quality parameters and sensory properties. Physicochemical parameters such as fruit size, weight, skin colour, flesh firmness, total soluble solids (TSS), titratable acidity and sensory properties (external appearance, skin colour, colour intensity, sourness, sweetness, ‘Ambrunes’ taste, crispness, texture and acceptance) were assessed at commercial maturity stage. Among quality characteristics evaluated, skin colour, fruit size and weight showed a prominent role in the segregation of the new selections, followed by flesh firmness and titratable acidity. However, TSS was not so decisive as the previous ones, because the cultivars showed a narrow range, whose values varied between 19-25 °Brix. According to sensory analysis, as relevant results, new selections of “Picota”-type that received the highest scores for global acceptance were directly related to those cultivars that showed fruits with higher size and dark-coloured skin.

Effects of Two Doses of Organic Extract-Based Biostimulant on Greenhouse Lettuce Grown Under Increasing NaCl Concentrations.

The enhancement of plant tolerance toward abiotic stresses is increasingly being supported by the application of biostimulants. Salinity represents a serious problem in the Mediterranean region. To verify the effects deriving from the application of biostimulants, trials on Romaine lettuce plants under salt exposure were performed, in greenhouse. Plants were subjected to three NaCl solutions with 0.8, 1.3, and 1.8 dS/m of electrical conductivity. The volume of the solution was 200 mL/plant and delivered every 3 days. Biostimulant treatments started after crop establishment and were: control (water) and two doses (0.1 or 0.2 mL/plant) of the commercial biostimulant Retrosal® (Valagro S.p.A), containing calcium, zinc, and specific active ingredients. Four Retrosal® treatments were applied, every 7 days, directly to the substrate. Non-destructive analyses were conducted to assess the effects on leaf photosynthetic efficiency. At harvest, plants fresh weight (FW) and dry weight were determined, as well as the concentration of chlorophylls, carotenoids, total sugars, nitrate, proline, and abscisic acid (ABA). The biostimulant tested increased significantly the FW of lettuce (+65% in the highest dose) compared to controls. Results indicate that treatments positively affected the chlorophyll content measured in vivo (+45% in the highest dose) and that a general positive effect was observable on net photosynthesis rate. Retrosal® seems to improve the gas exchanges under our experimental conditions. The total sugars levels were not affected by treatments. Biostimulant allowed maintaining nitrate concentration similar to the untreated and unstressed controls. The increasing levels of water salinity caused a raise in proline concentration in control plants (+85%); biostimulant treatments at 0.2 mL/plant dose kept lower the proline levels. All plants treated with the biostimulant showed lower value of ABA (-34%) compared to controls. Results revealed that Retrosal® is able to stimulate plant growth independently from the salinity exposure. However, treated plants reached faster the commercial maturity stage. The fresh biomass of control at the end of experiment, after 30 days, ranged from 15 to 42 g/head, while in biostimulant treated plants ranged from 45 to 94 g/head. The product applied at maximum dose seems to be the most effective in our experimental conditions.

Effect of calcium lactate in combination with hot water treatment on the nutritional quality of persimmon fruit during cold storage

Abstract Quality reduction and quick softening, occurring after harvest, limit shelf-life of persimmon fruit. In the present research, the effects of hot water and calcium lactate treatments on maintaining the firmness and preserving the quality of persimmon fruit during cold storage were investigated. ‘Karaj’ persimmon was harvested at commercial maturity stage and treated with hot water at three levels of 25 °C for 25 min, 45 °C for 30 min and 50 °C for 20 min, and calcium lactate at three levels of 0, 0.5 and 1%, and their combinations. The treated fruits were then stored at 1 °C with a relative humidity of ≥80%. At 20 and 40 days of the storage, fruits were removed from the refrigerator and some traits were evaluated three days after storage under shelf-life conditions. The evaluated traits were calcium content, firmness, weight loss, soluble tannin content, carotenoid, ascorbic acid, antioxidant capacity, total soluble solids and titratable acidity. The results showed that the amount of calcium in fruit tissue increased only in calcium lactate treatment, and hot water treatment showed a small effect on the trait. The combination of calcium lactate and hot water treatments caused higher effect on maintaining the firmness, controlling weight loss and preserving the quality of fruit when compared to applying each treatment alone. Furthermore, the treatments maintained antioxidant properties of the fruits during cold storage by maintaining the amount of soluble tannin, carotenoid and ascorbic acid contents. Thus, combined treatment of hot water and calcium lactate can be used to enhance antioxidant properties and preserve nutritional quality of persimmon fruits during postharvest storage.

Chemical profile and antioxidant potential of four table grape (Vitis vinifera) cultivars grown in Douro region, Portugal

The aim of this work was to improve the knowledge about the potential of Douro region (North of Portugal) to produce table grapes of superior quality. Skin, pulp, and seeds of four table grapes ‘Alphonse Lavallée’, ‘Cardinal’, ‘Dona Maria’ and ‘Muscat Hamburgo’ produced in Dour region, collected at commercial maturity stage, were evaluated. Phenolic compounds, organic acids and sugars were determined in each cultivar and in the different parts of the grape by HPLC-DAD, while the antioxidant properties were evaluated by DPPH, Cuprac and lipid peroxidation assays. Phenolics from different classes were found: four anthocyanins (delphynidin, cyanidin, petunidin and malvidin), two hydroxibenzoic acids (gallic acid and protocatechuic acid), three hydroxycinnamic acids (caffeic, chlorogenic and coumaric acids), one flavonol (rutin), three flavan-3-ols ((+)-catechin, (-)-epicatechin, and (-)-epicagallocatechin)), one oligomer (procyanidin B2) and one stilbene (resveratrol). In addition, three organic acids (tartaric, malic and citric acids) and two types of sugars (glucose and fructose) were detected in all samples. Differences were found between cultivars (p<0.001) and sample material type (p<0.001). Skins presented the higher content in anthocyanins, seeds in flavan-3-ols and pulps in phenolic acids, organic acids and free-sugars. The cultivar ‘Cardinal’ showed the highest content in phytochemicals, while ‘Dona Maria’ was the cultivar with the lowest content. Nonetheless, the content of flavan-3-ols and organic acids in ‘Dona Maria’, associated with its higher antioxidant capacity, makes it an interesting choice as table grape from healthier point of view. According to our results, Douro region have proper environmental conditions to produce these table grapes.

Influence of Storage Temperature, Hot Water, and 1-Mcp Treatments on the Postharvest Quality of ῾Karaj᾿ Persimmon

ABSTRACTThe present study was aimed at assessing the effect of storage temperature, hot water, and 1-MCP treatments on postharvest quality of ‘Karaj’ persimmon. To do so, fruits were harvested at the commercial maturity stage, treated with treatments of water at 25°C for 20 min (control), hot water at 45°C for 25 min, hot water at 50°C for 15 min, and 1-MCP at 500 nL.L−1 for 24 hours, and then stored at two temperatures of 1°C for 30 days and 13°C for 20 days. Finally, fruits were subjected to an astringency removal treatment (98% CO2 at 20°C for 24 h) before being transferred to shelf-life conditions for 5 days at 20◦C. Fruits’ quality was assessed after storage time and after shelf-life conditions, and the results showed that fruit tissue gelling, ethylene production, and ethanol and acetaldehyde contents increased in control fruit after cold storage at 1°C. The results also showed that at 1°C storage, the firmness of control fruits reduced and their coloration retarded. The existence of these symptoms in persimmon, which are chilling symptoms, showed that ‘Karaj’ persimmon is sensitive to chilling, but using treatments of 1-MCP and to some extent hot water at 50°C for 15 min effectively reduced these symptoms and maintained fruit quality. The fruits stored at 13°C soften quickly during storage, but gelling of fruit tissues did not occur and coloration was not affected. At this temperature, treatments of hot water and 1-MCP did not show a significant effect on the maintenance of the fruit quality compared to control.

Postharvest Attributes of “Washington Navel” Orange as Affected by Preharvest Foliar Application of Calcium Chloride, Potassium Chloride, and Salicylic Acid

ABSTRACTTo evaluate the effects of preharvest foliar application of calcium chloride (CaCl2), potassium chloride (KCl), and salicylic acid (SA) on postharvest quantitative and qualitative attributes and storage life of “Washington navel” orange, an experiment was conducted during two consecutive years. Solutions including CaCl2 (1.5% and 3%), KCl (1.5% and 3%), SA (0.015%, 0.03% and 0.045%), and the combination of CaCl2, KCl, and SA were sprayed on the canopy at the end of the first stage of fruit growth one month after full bloom (fruit diameter was 20 mm) and repeated in late September. The fruits were harvested at commercial maturity stage and were stored at 5°C with 85 ± 5% relative humidity (RH) for 90 days. Quantitative and qualitative characteristics were assessed every month. Preharvest KCl treatment had no significant effect on measured parameters. However, CaCl2 and SA treatments had the most impact on the quantitative and qualitative characteristics, such as firmness and phenolic content of fruit during storage. The SA treatment enhanced fruit appearance and nutritional value compared to the control but could not prevent the weight loss during storage. The results showed that preharvest spray of CaCl2, KCl, SA, and their combination had positive effects on storability of “Washington navel” orange fruit during storage. However, the effect of Ca and SA was more. Application of Ca, K, and SA could be beneficial for orange postharvest instead of mixed elements fertilizers.