Increase In Total Soluble Solids Research Articles

Development of Spray Drying of Powdered Oolong Tea Incorporated with Chinese Jujube Beverage

One useful economic crop which is utilized worldwide is Chinese jujube. It offers both nutritional and therapeutic benefits. Meanwhile, Oolong tea is a semi-oxidized form of tea which has a flavour that falls somewhere between black tea and green tea. Finally, spray-drying is an important technique used in food preservation. This current study sought to assess the most suitable use of Chinese jujube along with appropriate levels of maltodextrin when creating a mixed Oolong tea which incorporates Chinese jujube and is subsequently processed via spray-drying. Oolong tea served as the control sample, while evaluations were carried out on 60%, 70% and 80% blends of Chinese jujube with maltodextrin which served as a carrier agent at concentrations of 20 g, 30 g, 40 g and 50 g. These solutions underwent spray-drying where the respective inlet and outlet temperatures were 190°C and 80°C. An evaluation of the physico chemical, microbiological and sensory evaluation were performed. There was evidence of an increase in the total phenolic compounds, whereas in contrast there was a decline in antioxidant activity. L* and +a* showed no statistically significant difference, although for +b* a statistically significant difference was found. For products with mixed Chinese jujube and Oolong tea, the moisture, water activity and pH values were shown to be lower, although there was an increase in total soluble solids. In the evaluation, flavour and overall acceptability for Treatment 4 (80% Chinese jujube) achieved the highest respective ratings at 8.17 and 8.13 on the 9-point scale. This demonstrates that spray-drying can be beneficial in the context of powdered particles. The combination of Chinese jujube and powdered Oolong tea provides good antioxidant properties and offers strong potential for applications in the food sector.

Defoliation at berry set alters grape composition and gene expression during berry development in two Greek <i>Vitis vinifera</i> L. cultivars

The quality traits of a given grapevine cultivar are determined by the combinatorial action of the genotype, and environmental factors such as soil, landscape, and climate. Nonetheless, another critical factor is vineyard management. The forthcoming effects of climate change on viticulture represent a challenge for the application of sustainable practices. The impact of leaf removal at berry set stage on the Greek Vitis vinifera L. cultivars ‘Agiorgitiko’ and ‘Assyrtiko’ (a red- and white-berry cultivar, respectively) was investigated during the 2019 and 2020 vintages. Vine physiology measurements and berry sampling were performed at three phenological stages: green berry, veraison and harvest. Grape berry composition and the expression level of specific genes were analysed during ripening. Defoliation decreased berry weight in Assyrtiko, while no significant effect was observed in Agiorgitiko. The treatment resulted in a significant increase in total soluble solids and reduced acidity compared to the controls in both cultivars, while the effect on total phenols mainly depended on climate conditions. The expression profile of the genes examined was also altered during ripening, whereas the response to defoliation mainly depended on the vintage and the cultivar. Taken together, the results suggest that defoliation is a useful technique for maintaining grape and wine quality.

Physiological and biochemical variations of naturally ripened mango (Mangifera Indica L.) with synthetic calcium carbide and ethylene

To meet the increasing consumer demands for fruits, the implementation of artificial ripening techniques using synthetic chemicals has become increasingly commonplace among less ethical fruit production companies in today’s global market. The objective of present work was to establish a difference in the physiological and biochemical and profiles of naturally ripened mangoes vs. those ripened by application of synthetic calcium carbide and ethylene. The application of calcium carbide at 10 g/kg mangoes resulted early ripening in 2 days, with a 3-day shelf life, as compared with 5 and 6 days, for mangoes ripened by ethylene and naturally, respectively. Higher levels of calcium carbide reduced moisture, fiber, protein and carbohydrates content and increased the ash content of mangoes, as compared to higher levels of ethylene, whereas in naturally ripened mangoes the content percentages were 80.21, 3.57, 3.05 6.27 and 4.74, respectively. Artificial ripening resulted in significant loss of ascorbic, citric and malic acid, as values were recorded 35.94, 2.12 and 0.63 mg/g, respectively, in mangoes ripened with 10 g/kg of calcium carbide. However, in naturally ripened mangoes the amounts of these acids were recorded significantly (p < 0.05) high as 52.29, 3.76 and 1.37 mg/g, respectively. There was an increase in total soluble solids (TSS) and reducing sugars, and a decrease in titratable acidity in calcium carbide (10 g/kg) treated mangoes. Elemental analyses revealed high levels of minerals in naturally ripened mangoes, with significant values of iron (0.45 mg/100 g), zinc (0.24 mg/100 g) and copper (0.17 mg/100 g). The organoleptic quality of the fruit decreased significantly (p < 0.05) as a result of the use of calcium carbide. Although use of artificial ripening techniques provides speedy ripening of mangoes, there are obvious limitations. Consequently, natural ripening should be promoted in order to have safer and more nutritious mangoes.

Fruit maturity evolution of Clementine Mandarin variety (strain 88) grafted on different citrus rootstocks

Abstract. The research was carried out at Ciano Research Station of Lattakia Research Center - General Commission for Scientific Agricultural Research in Damascus in 2019. The fruit maturity evolution of Clementine Mandarin variety (Strain 88) budded on seven citrus rootstocks (Sour Orange, Citrumelo 4475, Citrumelo 1452, Troyer Citrange, Carrizo Citrange, Macrophylla and Cleopatra Mandarin) and planted in 1989 was studied for a period of 84 days, starting from 16th September 2019 to the start of reaping the fruits on 9th December 2019. There were insignificant differences in the average weight increase of the fruit among the studied treatments. Fruit peel thickness significantly increased by (50.15%) in the trees grafted on Macrophylla compared to those grafted on Cleopatra Mandarin, Troyer Citrange and Citrumelo 1452 whose fruit peel thickness increased by (19.21, 9.58 and 2.61%, respectively). The highest increase in total soluble solids (%) was in the trees grafted on Troyer Citrange by (38.10%), while total acids (%) significantly decreased by (18.33%) in the trees grafted on Citrumelo 1452.

Enhancing post-harvest quality of sapota using ultraviolet-C irradiation: A study on efficacy and effects.

Ultraviolet-C (UV-C) radiation has been identified as a promising method for enhancing the shelf life of fruits and vegetables by reducing microbial count and boosting their defence mechanisms. In this study, the impact of UV-C radiation on the physical, biochemical, and microbial properties of sapota fruits was investigated by subjecting them to different doses (2.5, 5, 7.5, and 10 kJ m-2; 12 ± 1°C; 85-90% relative humidity) to enhance their shelf life. The results revealed that higher doses of UV-C radiation resulted in significantly lower weight loss and higher firmness compared to untreated samples and samples treated with lower doses. Furthermore, UV-C-treated fruits displayed a delayed increase in total soluble solids, total sugar, and reduced sugar content compared to the untreated fruit during storage. The UV-C-treated fruits also exhibited a delayed decline in ascorbic acid and titratable acidity during storage. The treated fruits exhibited significantly higher phenolic content than the untreated fruits. Additionally, significantly lower decay and microbial count were observed in fruits treated with higher doses than in those treated with lower doses. The samples treated with a dose of 7.5 and 10 kJ m-2 had a shelf life of 25 days compared to 14 days for the control fruits.

Foliar application of Zinc and Boron improved physiological traits, productivity and shelf life of onion

Micronutrients play a crucial role in enabling crops and vegetables to achieve optimum productivity, improve storage quality, and overcome physiological disorders. The present study focuses on evaluating the effects of the foliar application of Zinc, Borax, and their combined application in enhancing onion yield and shelf life of Allium cepa L. (cultivars Red coral and Liberty). An experimental study was conducted for two years at Agriculture Research Unit, DIHAR Leh (34.1383˚N, 77.5725˚E) to assess the impact of different doses of ZnSO4, Borax, and their combination on onion yield and shelf-life improvement. Four treatments of ZnSO4 and Borax (T1: 0.5% ZnSO4; T2: 0.25% Borax; T3: 0.5% ZnSO4 + 0.25% Borax and T4: control) were applied twice, once at 30 DAT and again after 45 DAT. Among four treatments, T3 showed a significant impact on growth parameters, yield, and onion shelf-life followed by T1 and T2 compared to the control T4 treatment. Foliar sprays of ZnSO4 and Borax, rather than only ZnSO4 or Borax application, significantly improved plant height, leaves number, leaf area index, chlorophyll content, and onion yield. The storage examination revealed an important correlation between the concurrent application of ZnSO4 and Borax on onion, demonstrating a significant reduction in weight loss, an increase in Total Soluble Solids (T.S.S), and an extension of the onions’ shelf life. These findings hold the potential for significant implications in elucidating the optimal utilization of micronutrients for improving onion cultivation and preservation practices in cold desert regions of Ladakh.

Effect of water stress and foliar application of chitosan and glycine betaine on lettuce

The present study investigated the effect of foliar application of chitosan at 150 ppm and glycine betaine at 700 ppm on lettuce plants cv. Balady grown under well-watered and water deficit conditions in terms of growth, yield, quality, and water usage efficiency. The study was conducted in Qalubia Governorate, Egypt, during the two seasons of 2020/2021 and 2021/2022 on clay soil. Results indicated that water-stressed plants had a reduction in plant fresh weight, plant height, leaf area, and total yield, chlorophyll content and relative water content, while they exhibited an increase in total soluble solids, nitrate, and proline contents as well as water-use efficiency in both seasons. The foliar application of chitosan or glycine betaine to lettuce significantly improved plant performance under limited and normal irrigation conditions in comparison with untreated plants. The maximum positive effect was for chitosan foliar application. Overall, the results of this study indicated that foliar application of chitosan or glycine betaine was a substitute technology for improving the lettuce yield and quality as well as increasing water use efficiency under both irrigation regimes, but may be more efficient in lettuce plants subjected to a water deficit.

Biodegradable Mulching Film vs. Traditional Polyethylene: Effects on Yield and Quality of San Marzano Tomato Fruits.

Mulching is a common practice for improving crop yield and obtaining an out-of-season production, but when made using plastic materials it can bring environmental problems due to the management and the disposal of films at the end of the cropping seasons. To increase the sustainability of this practice, recently, mulching films made with biodegradable organic materials have become more widely used. Our aim was to evaluate the effect of a biodegradable mulching film on yield and qualitative traits of the San Marzano tomato fruits over two years (2014 and 2015). Two different types of mulching were tested: (i) black biodegradable film (MB12) and (ii) black low-density polyethylene (LDPE) were compared to bare soil (BS). Both mulching films elicited a 25% increase in yield, mainly due to the significantly higher number of fruits per square meter, compared to BS. Both mulching films also elicited a 9.9% increase in total soluble solids and a 57% increase in carotenoid content, while firmness showed the highest value in BS fruits. MB12 determined the highest value of the Hunter color ratio a/b of tomato fruits, followed by LDPE, while the lowest value was recorded in BS fruits. Both mulching films elicited an increase of 9.6%, 26.0%, and 11.7% for flavonoids, polyphenols, and AsA, respectively. In 2014, the MB12 degradation started at 71 days after transplant (DAT); in 2015, at 104 DAT. Therefore, replacing polyethylene with biodegradable film would seem to be an agronomically efficient and environmentally sustainable practice.

Effect of poly(L-lactic acid)/poly(ethylene glycol)-poly(L-lactic acid) block copolymer blend film on preservation of Chinese winter jujube (Ziziphus Jujuba Mill. cv. Dongzao)

The effect of poly(L-lactic acid)/poly(ethylene glycol)-poly(L-lactic acid) block film on preservation of Chinese winter jujube (Ziziphus Jujuba Mill.cv.Dongzao) was investigated. Eight arm poly(ethylene glycol)-poly(L-lactic acid) block copolymer (8-PEG/PLLA) and net structure 8-PEG/PLLA (NET-PEL) were successfully synthetized by ring-opening polymerization, and different percentages (5, 10, and 20 %) of them were blended with PLLA to prepared blends films. Mechanical properties, modulated different scanning calorimetry (MDSC), gas and water vapor permeability results showed that 8-PEG/PLLA and NET-PEL block copolymer greatly increased the toughness of blend films, could be decrease PLLA segment glass transition temperature (Tg)from 59.5 °C to 41.6–46.7 °C and cold crystallization temperature(Tcc)from 89.4 °C to 73.5–77.7 °C, and increased the oxygen (O2), carbon dioxide (CO2), and water vapor transmission rate. The an appropriate gas concentration [O2 (2.56–3.51 %), CO2 (5.05–5.56 %)] was created inside the PLLA/NET-PEL20% (NEPEL20)group, which could restrain increase of total soluble solids (TSS), malonaldehyde content. The firmness, color luminosity (L*), total phenols, and ascorbic acid were maintained at higher level，and kept its commercial value after 40 days of storage. The present data indicated that treating post-harvest winter jujubes with NEPEL20 MAP packaging was an effective method for preservation of postharvest winter jujube.

The effect of carboxymethylcellulose coating on the temperature-controlled storage of mangoes

Mango is a highly perishable tropical fruit with intense post-harvest metabolism, limiting its marketing period to distant regions. The application of edible coatings is an efficient way to preserve the quality of a fresh product during post-harvest storage. In the present research, the impact of a 3% carboxymethylcellulose (CMC) coating was studied on mangoes during storage at 20° C for 10 days. Results showed that treatment with 3% CMC delayed fruit maturation, suppressed the increase in total soluble solids, decreased firmness, and showed substantially higher titratable acidity, along with maintenance of skin color, in contrast to uncoated fruits. In conclusion, 3% CMC coating can be an effective approach for maintaining fruit quality of harvested mangoes during storage at 20°C.

Melatonin Treatment of Strawberry Fruit during Storage Extends Its Post-Harvest Quality and Reduces Infection Caused by Botrytis cinerea

Gray mold is a main disease of strawberry fruit (Fragaria × xananassa cv. Camino Real) caused by Botrytis cinerea, which leads to marketable value losses in the supply chain. The purpose of this study was to investigate the effects of exogenous melatonin (MT) on the physicochemical quality, antioxidant defense system, and disease resistance of strawberry fruit to B. cinerea infection. The results revealed that strawberry fruit immersed in 100 µM MT for 15 min effectively maintained its brightness and delayed the change in fruit color. MT also maintained the level of titratable acidity and slowed down the increase of total soluble solids in strawberry fruit. Moreover, strawberries immersed in MT maintained a fresh weight and fruit firmness, as well as reduced B. cinerea infection when compared to the untreated control fruit and fruit treated with 5% NaOCl. In addition, MT increased the accumulation of DPPH scavenging capacity and the activity of antioxidant enzymes (SOD, POD, and APX) with the exception of CAT. The same effect was also observed in strawberry fruit after immersion in MT and followed by B. cinerea inoculation. These findings demonstrated that exogenous MT could effectively maintain the postharvest quality of strawberries, even when the fruit was inoculated with B. cinerea.

Effect of Maleic Hydrazide and Waxing on Quality and Shelf-Life of Papaya (Carica papaya L.) Fruits

The effect of post-harvest treatment of Maleic hydrazide (MH)with and without waxing on the quality and shelf-life of ‘Baladi’ and‘Ekostika I’ papaya fruits at 18 ± 1 oC and 85% – 90% relative humiditywas evaluated. Maleic hydrazide at 250 and 500 ppm significantlydelayed fruit ripening by two and three days in both papaya cultivars,respectively, compared with untreated fruits. The higher theconcentration, the more was the delay in fruit ripening. The results alsoshowed that waxing in addition to MH resulted in a delay of two moredays in fruit ripening than treatment with MH alone. The effect of MHand waxing treatments in delaying papaya fruits ripening was manifestedin retarded respiratory climacteric, reduced weight loss and delayed fruitsoftening and increase in total soluble solids and ascorbic acid content

Quality Assessment of Burdekin Plum (Pleiogynium timoriense) during Ambient Storage.

Pleiogynium timoriense, commonly known as Burdekin plum (BP), is among many Australian native plants traditionally used by Indigenous people. However, only limited information is available on the nutritional and sensory quality of BP grown in Australia as well as its changes during storage. Therefore, this study evaluated the quality of BP during one week of ambient storage (temperature 21 °C, humidity 69%). Proximate analysis revealed a relatively high dietary fiber content in BP (7-10 g/100 g FW). A significant reduction in fruit weight and firmness (15-30% and 60-90%, respectively) with distinguishable changes in flesh color (ΔE > 3) and an increase in total soluble solids (from 11 to 21 °Brix) could be observed during storage. The vitamin C and folate contents in BP ranged from 29 to 59 mg/100g FW and 0.3 to 5.9 μg/100g FW, respectively, after harvesting. A total phenolic content of up to 20 mg GAE/g FW and ferric reducing antioxidant power of up to 400 μmol Fe2+/g FW in BP indicate a strong antioxidant capacity. In total, 34 individual phenolic compounds were tentatively identified in BP including cyanidin 3-galactoside, ellagic acid and gallotannins as the main phenolics. Principle component analysis (PCA) of the quantified phenolics indicated that tree to tree variation had a bigger impact on the phenolic composition of BP than ambient storage. Sensory evaluation also revealed the diversity in aroma, appearance, texture, flavor and aftertaste of BP. The results of this study provide crucial information for consumers, growers and food processors.

The improvement of guava (Psidium guajava) juice quality using crude multi-enzymatic extracts obtained from yeasts.

Guava juice is cloudy and viscous, which hinders filtration, decreases yield, and causes the loss of quality after its processing and during storage. This study aimed to evaluate enzymatic treatment effects using crude multi-enzymatic extracts (CME) obtained from Rhodotorula mucilaginosa, Rhodotorula orizycola, and Pseudozyma sp. produced by submerse fermentation in the extraction of juice guava. Mixtures of 100ml of guava pulp and multi-enzymatic extracts proposed by Doehlert planning were incubated under constant agitation at 150rpm and 50°C, and a Doehlert design was applied as a multivariate optimization strategy. The optimal conditions using the multi-enzymatic extract were: 0.4% (v/v) of CME for 131min for the multi-enzymatic treatment using Pseudozyma sp.; 3.0% (v/v) of CME for 154min using the R. mucilaginosa CME; and 5.0% (v/v) of CME for 90min using R. oryzicola. The maximum viscosity reduction values for the juices treated with the CME of yeasts were 10.33%, 86.38%, and 13.33% for the juices treated with the CME of Pseudozyma sp., R. mucilaginosa, and R. orizycola, respectively. The physical-chemical properties were improved after treatment with CMEs, yielding a reduction of clarity, increase of total soluble solids and reducing sugars, and decreasing the acidity (pH) for all treatments with enzymatic extracts of all strains. The yeasts studied showed a potential for CME production to be applied to juice, improving the quality of the juice, and R. mucilaginosa was the most prominent yeast due to most significant reduction of viscosity in guava juice.

Effect of orchard site and climatic conditions on plant nematode density levels

Phytoparasitic nematodes are commonly found in the soil and their presence can lead to plant diseases, weaker growth, reduced yields and lower fruit quality. A study conducted in 2006–2009, involving the monitoring of climatic conditions, identified the influence of precipitation and temperature on the number of nematodes, in 7 sites within a cherry orchard. Soil samples to assess nematode populations were taken from 7 sites that differed in terms of cultivation and age: 5 cherry orchards established in different years. Not all nematode taxa responded in the same way to temperature increase. Members of the families Belonolaimidae, Trichodoridae and the genus Aphelenchus increased in number with rising temperatures. The negative water balance limited the number of nematodes in the soil in the layer up to 30 cm, whereas the increase in soil moisture had a positive effect on the development of Paratylenchus spp., and mebers of the family Hoplolaimidae and Heterodera. The largest total number of nematodes was found on the strip cultivated with agricultural crops after orchard liquidation. However, parasitic nematodes accounted for were at low levels (17%). The size of fruits from trees growing on sites with a large number of nematodes decreased with a simultaneous increase in total soluble solids and fruit firmness.

Effects of Phospholipase D Inhibitors Treatment on Membrane Lipid Metabolism of Postharvest Banana Fruit in Response to Mechanical Wounding Stress

Banana fruit is a widely cultivated and economically important crop, and it is susceptible to mechanical damage. The effects of three different phospholipase D inhibitors (0.1% n-butanol, 0.05% 2-butanol, and 0.1% hexanal) on the cell membrane integrity and membrane lipid metabolism in wounding banana fruits during storage were investigated. The results indicated that wounded banana treated with phospholipase D inhibitors showed significant (p &lt; 0.05) delay in the ripening and senescence process than the control group after a 9-day storage. Of the three PLD inhibitors, hexanal showed the best effect in maintaining firmness, suppressing the increase of total soluble solids (TSS) and respiration rate, and reducing malondialdehyde (MDA) content and cell membrane permeability of wounded banana fruits. Furthermore, hexanal more efficiently decreased the phospholipase D (PLD) and lipoxygenase (LOX) activities, lowered the contents of phosphatidic acid (PA) and diacylglycerol (DAG), and inhibited the reduction of phosphatidylcholine (PC) and phosphatidylinositol (PI) after 6 days of storage, compared to n-butanol or 2-butanol. These results demonstrate that application of hexanal treatment may be a reliable method to delay the senescence of harvested bananas subjected to mechanical wounding.

Partial double-pruning after bloom delays bunch rot epidemics in &lt;i&gt;Vitis vinifera&lt;/i&gt; L. cvs. Riesling and Pinot gris

Bunch rot caused by Botrytis cinerea is a major fungal disease in grapevines. Under humid climatic conditions, bunch rot development on grapes cannot be completely suppressed and bunch rot control strategies mainly aim to delay the epidemic. In the present study, we investigated the potential of the innovative cultural practice “partial double-pruning after bloom (PDP)” to delay the bunch rot epidemic on Pinot gris and Riesling cultivars over five consecutive seasons (2016-2020) in Remich/Luxembourg. Control vines were pruned at winter to one 10-node fruiting cane per vine, while in PDP, two 10-node fruiting canes per vine were kept; one of the two canes was removed at BBCH 73 (2-3 weeks after bloom).In all the 10 cultivar*year combinations, the bunch rot disease severity at the final assessment date (shortly before harvest) was lower in PDP than in the control. This reduction was significant (P £ 0.05) in 7 of the 10 cultivar*year combinations. PDP significantly delayed the date when 5 % disease severity was reached; in data pooled over the five years this delay ranged between 10.3 (Pinot gris) and 8.3 days (Riesling). The proportion of non-marketable fruit was significantly reduced by 41 % (Pinot gris) and 53 % (Riesling). Total yield per plant was reduced by 10 % (Pinot gris) and 19 % (Riesling), with a significant increase in total soluble solids at harvest in the case of Riesling. An additional evaluation in the year 2020 revealed reduced cluster compactness in PDP for both cultivars.PDP turned out to be an innovative, efficient, reliable and relatively cost-efficient cultural practice to delay the bunch rot epidemic in grapes. It can be integrated as one module into the best practice strategy to control bunch rot and contributes to pesticide reduction in viticulture.

Synchronization of zinc and boron application methods and rates for improving the quality and yield attributes of Mangifera indica L. on sustainable basis

Deficiency of micronutrients is a major hurdle for achieving good quality mango fruit and sustainable optimum yield. High soil pH and phosphorus fertilizers are major causes that restrict the bioavailability of micronutrients, such as zinc (Zn) and boron (B). In addition, low or no micronutrient application may create severe Zn and B deficiency in fruits, especially mango. The judicious use of Zn and B is critical to overcoming this problem. Application of both nutrients in the form of soil and foliar application can increase the uptake of Zn and B and the yield of mango fruit on a sustainable basis. However, time is needed to synchronize micronutrients to application methods. Therefore, the current experiment was conducted to explore the best application rate of both micronutrients to the application method in mango orchards. There were 14 treatments applied with three replications. For micronutrient application, soil and foliar methods were chosen. Results showed that 75SB + 0.8FB + 150SZn + 1.0FZn perform significantly best for the improvement in the fruit length (62 %), fruit width (57 %), pulp fresh weight (92 %), stone weight (72 %). Furthermore, a significant increase in total soluble solids (45 %) and a decrease in acidity (50 %) confirmed the imperative functioning of 75SB + 0.8FB + 150SZn + 1.0FZn over control. Furthermore, a significant reduction in total phenolic contents and juice pH validated the effectiveness of 75SB + 0.8FB + 150SZn + 1.0FZnover control in mango. In conclusion, Zn and B soil and foliar application is a better approach for achieving good quality mango fruit. Treatment 75SB + 0.8FB + 150SZn + 1.0FZnis best for mango growers to achieve maximum fruit yield. However, more investigation is suggested in different climatic zones to declare 75SB + 0.8FB + 150SZn + 1.0FZnas the best application amendment to maximize the yield and quality of mango.

Gene Expression, Activity and Localization of Beta-Galactosidases during Late Ripening and Postharvest Storage of Tomato Fruit

Beta-galactosidases (β-GALs) hold a key role in both fruit softening and the increase of total soluble solids during maturation. Despite determining both quality and potential postharvest longevity, β-GAL activity during ripening, with a special focus on the postharvest period, has not been adequately addressed in a spatial and temporal manner. This study focused on the regulation of gene expression in relation to the total β-GAL enzyme activity during the ripening of tomato fruit attached on the plant, as well as harvested fruit ripened for 5 d at 4, 10, or 25 °C. The transcription of genes coding for β-GAL isoenzymes was significantly affected by both the fruit maturation stage (unripe vs. red ripe) and postharvest storage temperature. Cold stressed tomatoes (4 °C) exhibited a remarkably higher transcription of most β-GAL genes compared to on-plant red ripe fruit and to fruit exposed to either 10 or 25 °C, indicating a low temperature response. However, enzymatic activity and water-soluble pectin content increased with elevated temperature exposure, peaking in fruit stored at 25 °C. β-GAL activity was present in the pericarp, while it was less detected in locular parenchyma. These findings highlight the dual role of β-GAL not only in maturation, but also in the metabolism during postharvest homeostasis and cold acclimation of tomato fruit.

Carboxymethyl cellulose coating regulates cell wall polysaccharides disassembly and delays ripening of harvested banana fruit

Banana is a perishable fruit that ripens and deteriorates quickly after harvest. In this work, we investigated the impact of a dip in carboxymethyl cellulose (CMC) at concentrations of 0.5%, 1.0% and 1.5% on the quality of harvested bananas during storage at ambient conditions of 20 ± 1 ºC for a 15-d period. It was noted that 1.5% CMC markedly delayed the occurrence of decay incidence (9%) and suppressed physiological weight loss (6%). The 1.5% CMC treatment suppressed the activities of chlorophyllase, pheophytinase, Mg-dechelatase and chlorophyll (Chl)-degrading peroxidase (POD), which ultimately delayed banana peel color changes by conserving higher total Chl contents and reducing the accumulation of carotenoids. This subsequently resulted in higher L* and a* along with a lower increase in b* values as compared with control. Banana fruit coated with 1.5% CMC exhibited delayed ethylene and respiration peaks in comparison with control. In the same way, 1.5% coating maintained higher firmness and showed higher contents of protopectin, chelate-soluble pectin, sodium carbonate soluble pectin, cellulose and hemicellulose along with lower water-soluble pectin due to reduced activities of cellulase, pectin methylesterase, polygalacturonase and β-glucosidase. In the same way, postharvest application of 1.5% CMC coating suppressed the increase in total soluble solids (TSS) and showed higher titratable acidity (TA) along with a lower ripening index (TSS/TA ratio) in flesh of banana fruit compared with control. In conclusion, 1.5% CMC application could be an appropriate coating concentration to delay the ripening and rapid softening of harvested bananas stored in ambient conditions.