Decrease In Ascorbic Acid Content Research Articles

Effect of Dynamic High-Pressure Microfluidization on the Quality of Not-from-Concentrate Cucumber Juice.

The effects of dynamic high-pressure microfluidization (DHPM at 400 MPa) and heat treatment (HT) on the microbial inactivation, quality parameters, and flavor components of not-from-concentrate (NFC) cucumber juice were investigated. Total aerobic bacteria, yeasts and molds were not detected in the 400 MPa-treated cucumber juice. Total phenolic content increased by 16.2% in the 400 MPa-treated cucumber juice compared to the control check (CK). The significant reduction in pulp particle size (volume peak decreasing from 100-1000 μm to 10-100 μm) and viscosity increased the stability of the cucumber juice while decreasing the fluid resistance during processing. HT decreased the ascorbic acid content by 25.9% (p < 0.05), while the decrease in ascorbic acid content was not significant after 400 MPa treatment. A total of 59 volatile aroma substances were identified by gas chromatography-ion mobility spectrometry (GC-IMS), and a variety of characteristic aroma substances (i.e., valeraldehyde, (E)-2-hexenal, (E)-2-nonenal, and (E,Z)-2,6-nonadienal, among others) were retained after treatment with 400 MPa. In this study, DHPM technology was innovatively applied to cucumber juice processing with the aim of providing a continuous non-thermal processing technology for the industrial production of cucumber juice. Our results provide a theoretical basis for the application of DHPM technology in cucumber juice production.

Novel edible coating based on Macadamia Nut oil and chitosan to maintain the antioxidant and physical properties of tomato fruits

Innovative approaches for extending the shelf life of tomatoes are required due to increased postharvest losses of climacteric-fruits. The use of edible coatings is recently considered as a promising approach due to their non-toxicity and affordability properties. The coatings form physical barriers that alter the internal atmosphere of the fruit and slow down a ripening process. The influence of an edible coating comprising of chitosan and macadamia nut oil on the antioxidant and physical properties of tomato fruits is reported. The antioxidant and physical qualities of tomato fruits were investigated using different coating solutions. Various concentrations of macadamia nut oil, ranging from 1 % to 2.5 %, were used as independent coating solutions. Additionally, another set of coating solutions was prepared by mixing macadamia nut oil in the same concentration range (1 % to 2.5 %) with 1 % w/v chitosan. The tomatoes were dipped into the coating solutions and stored under a postharvest shed (23.8–30 °C, 65.8–97.5 % RH) for 20 days to monitor total phenolic content, total flavonoid content, ascorbic acid content, color, percentage weight loss, decay percentage, and shelf life after every 5-days interval. The results showed a significant difference (P < 0.05) between coated and uncoated tomato samples. The coated tomatoes showed the significant retention of total flavonoid content, total phenolic content, hue angle and red-green (a*) compared to uncoated tomatoes. On contrast, the decrease of decay, weight loss, the lightness (L), blue-yellow (b*), chroma, and ascorbic acid content was lower for coated compared to control tomatoes. The findings indicated that 1 % macadamia nut oil exhibited the highest retention of antioxidant and physical properties, and lowest decrease in ascorbic acid content from 0.014 mg/100 g on the 5th day to 0.0096 mg/100 g on the 20th day was observed. Thus, the findings from this study suggest that the macadamia nuts can serve as a cheap and low-cost source of edible oil suitable for prolonging the shelf life of tomatoes and related fruits.

Kiwifruit Monodehydroascorbate Reductase 3 Gene Negatively Regulates the Accumulation of Ascorbic Acid in Fruit of Transgenic Tomato Plants.

Ascorbic acid is a potent antioxidant and a crucial nutrient for plants and animals. The accumulation of ascorbic acid in plants is controlled by its biosynthesis, recycling, and degradation. Monodehydroascorbate reductase is deeply involved in the ascorbic acid cycle; however, the mechanism of monodehydroascorbate reductase genes in regulating kiwifruit ascorbic acid accumulation remains unclear. Here, we identified seven monodehydroascorbate reductase genes in the genome of kiwifruit (Actinidia eriantha) and they were designated as AeMDHAR1 to AeMDHAR7, following their genome identifiers. We found that the relative expression level of AeMDHAR3 in fruit continued to decline during development. The over-expression of kiwifruit AeMDHAR3 in tomato plants improved monodehydroascorbate reductase activity, and, unexpectedly, ascorbic acid content decreased significantly in the fruit of the transgenic tomato lines. Ascorbate peroxidase activity also increased significantly in the transgenic lines. In addition, a total of 1781 differentially expressed genes were identified via transcriptomic analysis. Three kinds of ontologies were identified, and 106 KEGG pathways were significantly enriched for these differently expressed genes. Expression verification via quantitative real-time PCR analysis confirmed the reliability of the RNA-seq data. Furthermore, APX3, belonging to the ascorbate and aldarate metabolism pathway, was identified as a key candidate gene that may be primarily responsible for the decrease in ascorbic acid concentration in transgenic tomato fruits. The present study provides novel evidence to support the feedback regulation of ascorbic acid accumulation in the fruit of kiwifruit.

Exploring the potential of aloe vera gel-based coating for shelf life extension and quality preservation of tomato

ABSTRACT Tomato is considered the world’s most important crop owing to its high nutritional profile and flavor. However, its limited shelf life and post-harvest losses impact its marketing. The present study investigated the impact of aloe vera gel-based edible coating on tomato’s post-harvest quality under storage at 8°C for 12 days. The aloe vera-based coating solutions were made with varying concentrations of extracted gel that varied from 0 to 60% with inclusion of chitosan (0.5 to 2%). Physiological, chemical, nutritional, and microbiological analysis of coated and uncoated tomatoes was carried out during storage. It was found that uncoated (control) tomatoes showed maximum weight loss (5.85%), total soluble solids (5.3 ± 0.20 0Brix), change in pH (5.6 ± 0.26), microbial count (3.57 ± 0.12 log cfu/g), decrease in ascorbic acid content (19.23 ± 0.92 mg/100 g), and acidity (0.54 ± 0.01%) as compared to aloe vera-based coatings. However, the coating formulation comprising aloe vera gel (60%) + chitosan (2%) performed much better than other prepared coatings in delaying the weight loss (2.1%), total soluble solid (3.7 ± 0.16 0Brix), change in pH (4.6 ± 0.21), ascorbic acid value (30.47 ± 1.31 mg/100 g), acidity (0.83 ± 0.04%), and microbial load (1.6 ± 0.08 log cfu/g). In addition, it also maintained firmness and color of tomatoes during storage of 12 days. Conclusively, the application of aloe vera-based coating (60% gel) with the inclusion of chitosan (2%) may be proposed for preserving the post-harvest quality of the tomatoes.

Dynamic Physiological Responses of Cinnamomum camphora with Monoterpene Protection under High Temperature Shock

Monoterpenes can protect plants against high temperature, but the early events of protection are still unknown. In this study, the dynamic variations in reactive oxygen species metabolism, photosynthetic capacity, and related gene expression in linalool, eucalyptol, and camphor chemotypes of Cinnamomum camphora with and without monoterpene emission under 6 h high-temperature stress were investigated. With respect to the control (28 °C), 40 °C and Fos + 40 °C (fosmidomycin inhibited monoterpene biosynthesis under 40 °C) treatments increased H2O2 and thiobarbituric acid reactive substance levels in the three chemotypes, but without significant differences between the two treatments after 2 h. Compared with the 40 °C treatment, the Fos + 40 °C treatment further aggravated the increase after 4 h, with increases of 13.8%, 12.3%, and 12.3% in H2O2 levels as well as 16.5%, 17.4%, and 9.1% in thiobarbituric acid reactive substance levels, respectively, in linalool, eucalyptol, and camphor chemotypes. When the three chemotypes were treated with 40 °C and Fos + 40 °C, the ascorbic acid content was gradually decreased during the 2 h treatment. After 4 h, the Fos + 40 °C treatment further aggravated the decrease in ascorbic acid content, with decreases of 10.6%, 9.8%, and 20.1%, respectively, in the eucalyptol, linalool, and camphor chemotypes. This could be caused by the further down-regulation of the key gene GGP in antioxidant biosynthesis. Meanwhile, two genes (VTE3 and 4CL) in other non-enzymatic antioxidant formation were also further down-regulated in Fos + 40 °C treatment for 4 h. These might lead to the further increase in reactive oxygen species levels in Fos + 40 °C treatment lacking non-enzymatic antioxidants. The photosynthetic electron yield and transfer (φPo, Ψo and φEo) in the three chemotypes were significantly (p &lt; 0.05) decreased under the 40 °C and Fos + 40 °C treatments for 0.5 h, and the photosynthetic rate was significantly (p &lt; 0.05) decreased in the two treatments for 1 h. After 4 h, the Fos + 40 °C treatment aggravated the decrease, as the genes encoding the components of photosystem II (psbP and psbW) and ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcS and rbcL) were further down-regulated. These dynamic variations in the early events suggested that monoterpenes should act as signaling molecules to improve plant thermotolerance, as blocking monoterpene biosynthesis did not cause immediate effects on the physiological responses in contrast to the monoterpene-emitting plants during the 2 h high temperature stress, but resulted in serious damages after 4 h for suppressing related gene expression. This not only provides new proof for the isoprenoid thermotolerance mechanism by serving a signaling function, but also promotes the utilization of monoterpenes as anti-high-temperature agents, and the cultivation of high-temperature tolerance varieties with abundant monoterpene emission.

Chronic Antioxidant Capacity Loss in Anterior Chamber Environment After Iridectomy.

To compare the ascorbic acid concentration and total antioxidant capacity in the aqueous humor of pigmented Rex rabbits after sham operation (control), iridectomy, and trabeculectomy. Pigmented Rex rabbits were divided into control, iridectomy, and trabeculectomy groups and followed up for 12 months after surgery. Ascorbic acid concentration and total antioxidant capacity in the aqueous humor, intraocular pressure, and the occurrence of cataracts were examined in each group. The ascorbic acid concentration and total antioxidant capacity after iridectomy and trabeculectomy were significantly lower at one week and at one, six, and 12 months after operation than those in the control group (P ≤ 0.03). Ascorbic acid concentration was positively and significantly correlated with total antioxidant capacity in the aqueous humor (P < 0.01). Compared to the control and the iridectomy groups, intraocular pressure in the trabeculectomy group was significantly lower at one week and at one and six months after surgery (one week: P < 0.01 and P < 0.01, respectively; one month: P < 0.01 and P = 0.03, respectively; six months: P = 0.03). Histological findings in the iridectomy and trabeculectomy groups included the appearance of vacuoles in the lens at six and 12 months after surgery. Iridectomy causes a sustained decrease in ascorbic acid concentration, followed by a long-term decrease in the total antioxidant capacity within the aqueous humor. The animal model possibly predicts the vulnerability focusing on the antioxidant level in the anterior chamber environment after trabeculectomy and iridectomy per se in clinical settings.

Morpho-physiological characterization and metabolic profiling of rice lines for immunity to counter Helminthosporiumoryzae

Heliminthosporium oryzae is a necrotrophic fungal pathogen that effect rice crops grown on millions of hectares. We evaluated nine newly establishing rice lines and one local variety for resistance against H. oryzae. Significant (P ≤ 0.05) differences in response to pathogen attack were recorded in all rice lines. Maximum disease resistance was recorded in Kharamana under pathogen attack as compared to uninfected plants. A comparison of decline in shoot length revealed that Kharamana and Sakh experienced minimum lost (9.21%, 17.23%) in shoot length respectively against control while Binicol exhibited highest reduction (35.04%) in shoot length due to H. oryzae attack. Post-infection observations of shoot fresh weight revealed 63% decline in Binicol and declared it as the most susceptible rice line. Sakh, Kharamana and Gervex exhibited minimum fresh weight decrease (19.86%, 19.24% and 17.64% respectively) as compared to other lines under pathogen attack. Maximum chlorophyll-a contents were recorded in Kharamana under control and post pathogen attackconditions. Following the inoculation of H. oryzae, SOD was increased up to 35% and 23% in Kharamana and Sakh. However, minimum POD activity was recorded in Gervex followed by Swarnalata, Kaosen and C-13 in non-inoculated and pathogen-inoculated plants. Significant decrease in ascorbic acid contents (73.7% and 70.8%) was observed in Gervex and Binicol that later contributed in their susceptibility to H. oryzae attack. Pathogen attack caused Significant (P ≤ 0.05) changes in secondary metabolites in all rice lines but minimum total flavonoids, anthocyanin and lignin were observed in Binicol in uninfected plants and attested its susceptibility to pathogen. In post-pathogen attack conditions, Kharamana showed best resistance against pathogen by exhibiting a significantly high and maximum value of morpho-physiological, and biochemical attributes. Our findings suggest that tested resistant lines can be further explored for multiple traits including molecular regulation of defense responses to breed immunity in rice varieties.

Improvement of the UV-resistance capability of fish gelatin-oxidized starch film via inserting mycosporine-like amino acids.

Mycosporine-like amino acids (MAAs) are known as the strongest solar guardians in nature. In the present study, the extraction of MAAs from dried Pyropia haitanensis was achieved. Fish gelatin and oxidized starch composite films embedded with MAAs (0-0.3% w/w) were fabricated. The maximum absorption wavelength of the composite film appeared at 334 nm, which was consistent with MAA solution. Furthermore, the UV absorption intensity of the composite film was highly dependent on the concentration of MAAs. The composite film exhibited excellent stability during the 7-day storage period. The physicochemical features of composite film were demonstrated by the measurement of water content, water vapor transmission rate, oil transmission, and visual characteristics. Furthermore, in the actual anti-UV effect investigation, the increase in peroxide value and the acid value of grease under the films coverage was delayed. In the meantime, the decrease in ascorbic acid content in dates was postponed, and survivability of Escherichia coli was increased. Our results suggest that fish gelatin-oxidized starch-mycosporine-like amino acids film (FOM film) with biodegradable and anti-ultraviolet properties has a high potential for usage in food packaging materials. © 2023 Society of Chemical Industry.

Browning mechanism in stems of fresh‑cut lettuce

Cellular fluids and latex released from cut cells in the stems of lettuce when it is harvested are the major source of stem browning. In the present study, the browning process of cellular fluids and latex released from romaine and iceberg lettuce stems was investigated. An increase in LOX enzyme and total phenolics also occurs during lettuce stem browning. A decrease in ascorbic acid content, an increase in phenylalanine ammonia lyase and lipoxygenase activity were important factors responsible for the browning. Metabolomic and proteomic analyses indicated that changes in the level of glutathione metabolism, indole alkaloid biosynthesis, oxidative phosphorylation, galactose metabolism were also associated with stem browning. The main causes of stem browning in fresh cut lettuce were comprehensively investigated in the present study and the resulting data provided information that can be used in the study of browning in lettuce and other vegetables during harvest or fresh-cut processing.

Transcriptome and Metabolome reveal AsA regulatory network between metabolites and genes after fruit shading by bagging in kiwifruit (Actinidia eriantha)

• The molecular mechanism of AsA changes in Actinidia eriantha after bagging has been studied for the first time. • Through untargeted metabolomics and RNA-Seq of the A. eriantha ‘Ganlv 1′ fruit after bagging were analyzed to reveal the metabolites changes and the underneath gene expression network changes. • Provide novel insights into the effects of bagging on changes in the intrinsic and appearance quality of A. eriantha fruit. Fruit bagging is an effective way of producing pollution-free fruit. However, the micro-environment provided by bagging for fruits could reduce the internal quality for most fruits in various degree. As a novel berry fruit, kiwifruit ( Actinidia eriantha ) has great potential for development. We found a change in fruit quality after fruit shading by bagging (FSB). In order to explore the regulatory mechanism of FSB on fruit quality, we used off-target metabolomics and transcriptomics to identify differential metabolites and differential genes, and focused on the molecular mechanism of the decrease in AsA content. We found that the contents of soluble solids (SSC), soluble sugar (SS), ascorbic acid (AsA), chlorophyll and carotenoid in the FSB fruit were significantly reduced. Through the non-targeted metabolome, a total of 160 metabolites showed significant differences in fruit tissue. There were 3,200 differentially expressed genes (DEGs) between FSB and control by RNA-Seq and enriched in 118 KEGG metabolic pathways. The decrease of AsA content after FSB was mainly due to the decrease of DHAR gene, MDHAR gene, APX gene and the increase of MDHA metabolite during the AsA-GSH cycle process. The decrease of GalUR gene in d -galacturonic acid pathway and the decrease of GulLO gene and Myo-inositol metabolite in Myo-inositol pathway were the secondary reasons for the decrease of AsA content. This study would provide novel insights into the effects of FSB on changes in the intrinsic and appearance quality of A. eriantha fruit.

Postharvest Preservation of Thai Mango var. Chok-Anan by the Combination of Pulsed Electric Field and Chemical Pickling

Mango is one of the most favorable tropical fruits grown and consumed in several parts of the world. However, there is overproduction during the ripening stage. In this situation, appropriate techniques are needed to utilize the abundant supply. Pickling is one of the oldest and most successful methods for preserving mango. In this study, mango pickles were prepared by using chemical pickling assisted with pulsed electric field (PEF). The physicochemical and textural properties of mango pickles prepared with PEF at 30 and 50 °Brix were studied in comparison with the conventional pickling process. The water loss, solids gain, and diffusion efficiency were increased by twofold when PEF was applied in pickling Thai mango variety Chok-anan. This process also reduced the moisture content and water activity. The PEF-assisted pickling process caused changes in lightness (L*) and redness (a*) values. The textural properties of the mango pickles produced by the PEF-assisted pickling process were also changed. In addition, the PEF-assisted pickling process caused a 20% increase in beta-carotene content and a 47% decrease in ascorbic acid content. The microstructure of the mango was more disintegrated on the surface after PEF than that from the conventional pickling process.

TOPINAMBOUR MAIN COMPONENTS CONTENT DETERMINATION IN THE PROCESS OF STORAGE VIA ANALYTICAL AND PHYSICOCHEMICAL ANALYSIS METHODS

Paper is devoted to the study of topinambour's biologically active substances through analytical and physico-chemical analysis methods.&#x0D; In the course of experiment, content of inulin and vitamins in topinambour was determined, using methods of analytical chemistry, which was: inulin – 65,43 μg/100 g, vitamin C – 100,12 μg/100 g, beta-carotene – 55,26 μg/100 g.&#x0D; Change in inulin mass fraction in topinambour's raw material powder during its storage at different temperatures was investigated. During seven months topinambour tubers storing at different temperature conditions, the mass fraction of inulin was larger in altered into powder and dried raw materials - 60 %, then in freezer – 50 % and the smallest mass fraction was in refrigerator – 20 %.&#x0D; Сhange in ascorbic acid mass fraction by means of titrimetric analysis method was investigated. A sharp decrease of ascorbic acid content in tuber's powder was observed, it is due to vitamin inactivation under high temperatures in the process of raw materials drying. Content of ascorbic acid in cooled tubers (4 ± 2) °С to the end of shelf-life decreased by 60 %. The best results were obtained in frozen tubers (–20 ± 2) °C, content of ascorbic acid in them has changed 12–15 % compared to control sample.&#x0D; Beta-carotene content was determined by photocolorimetric method according to standard methods. Content of β-carotene decreased to a level 12 % by the end of shelf life in topinambour's tuber powder. In frozen tubers (–20 ± 2) °С content of β-carotene was accompanied by a decrease in the mass fraction of β-carotene throughout whole storage period and amounted to 60 %. The best results were obtained in tubers that overwintered in soil, vitamin's mass fraction in them decreased by only 10 %.&#x0D; When storing topinambour's tubers at different temperature conditions, proportion of vitamins is the highest in tubers that have overwintered in soil, then in the freezer and the lowest in the refrigerator.&#x0D; Recommendations on the method of topinambour's storage with maximum preservation of biologically active substances content were given. &#x0D; Dried topinambour's tuber powder is most suitable for long-term storage with minimal loss of inulin and beta-carotene, which allows to use this powder in the production of therapeutic and prophylactic drugs. &#x0D; When stored at temperatures (–20 ± 2) °C there is a sharp decrease in nutrients in the first two months and a further decrease is very slow. Such storage is expedient if it is necessary to keep tubers for a long time. For example, in production of topinambour's preparations it is necessary to provide а plant with raw materials for the winter. &#x0D; Storage in refrigerator at a temperature of (4 ± 2) °C is advisable for a short period of time. Decrease of inulin and vitamins content is not rapid, in such conditions it can be stored for two months. In the long period, tubers wither and pathogenic microflora begins to develop on them.&#x0D; The best indicators in all biologically active substances were stored in tubers that overwintered in the soil. Because the top layer in topinambour does not protect cells from decay processes, these processes are activated during digging, and tubers, that were left in the soil, continue to functionate, so cell apoptosis is not activated.

Preservation of mandarins using a microbial decontamination system integrating calcium oxide solution washing, modified atmosphere packaging, and dielectric barrier discharge cold plasma treatment

A new microbial decontamination system integrating with calcium oxide solution washing (CaOW), packaging in modified atmosphere (MAP), and treatment with dielectric barrier discharge cold plasma (CPT) was developed and its effects on mandarin storability were investigated. CPT was applied for 2 min at 27 kV to mandarins, formerly prepared with and without CaOW for 3 min and packaged with air or O2-CO2-N2 (9.9, 2.1, and 88.0%, respectively). CaOW-CPT effectively retarded the decrease in the ascorbic acid concentration and antioxidant capacity of mandarin flesh at 4 °C and 25 °C, and its total phenolic content (TPC) at 25 °C. Modified atmosphere more effectively delayed the increase in the concentration of CO2, generated by mandarins at 4 °C and 25 °C and the decrease in flesh TPC at 4 °C than air-packaging (p < 0.05). Both CaOW and MAP increased the efficiency of CPT in inhibiting Penicillium digitatum growth, immediately after treatment and during storage at 25 °C. The microbial decontamination system integrating CaOW, MAP, and CPT effectively retarded the decrease in ascorbic acid concentration and antioxidant activity of the flesh during storage at 4 °C and 25 °C, without influencing the pH and color of mandarins at both temperatures. This study demonstrated the technological potential of the microbial decontamination system combining CaOW, MAP, and CPT for extending the shelf life of mandarins.

Effects of kiwi's pectin methylesterase inhibitor, nanomilling and pasteurization on orange juice quality.

Endogenous pectin methylesterase (PME) is the enzyme responsible for phase separation and cloud loss in orange juice (OJ) manufacturing. The effect of kiwi's PME inhibitor (PMEI), nanomilling, and pasteurization on OJ quality was evaluated. The microbial quality, PME activity, OJ separation, pH, ascorbic acid content and the sensory characteristics of the juice were followed during 5 weeks storage (4°C). PMEI as freeze‐dried kiwi powder (0.3%, w/w) succeeded in inhibiting 89.3% of the OJ PME without affecting the microbial and the sensory quality. Nanomilling of OJ pulp, to prepare nano‐particles OJ (NPOJ), reduced the initial microbial load by 1.65 and 1.83 log for psychrotrophs and yeasts and molds, respectively; significantly (p < .05) inactivated 40.9% of the residual PME activity and the juice separation was significantly reduced by 48.3% (after 14 days of storage). Nanomilling exhibited no effect on OJ pH, but slight (p < .05) decrease in ascorbic acid content was noted. The combination of PMEI with NPOJ resulted in improved OJ stability with reduced separation to 36.4% of that of control. Such combination also allowed to use a lower pasteurization temperature at lower exposure time (60°C/5 min) needed to obtain new NPOJ with comparable high quality as fresh OJ and which has a shelf life of 3 weeks (4°C).

The ascorbate peroxidase 1 regulates ascorbic acid metabolism in fresh-cut leaves of tea plant during postharvest storage under light/dark conditions

Postharvest storage conditions affect the ascorbic acid (AsA) levels in fresh-cut leaves of horticultural crops. However, the detailed mechanism of AsA metabolism in the fresh-cut leaves of tea plant (Camellia sinensis) during postharvest storage under light/dark conditions remains unclear. To investigate the AsA mechanism, we treated fresh-cut tea leaves with light/dark during postharvest storage. An ascorbate peroxidase 1 (CsAPX1) protein involved in AsA metabolism was identified by iTRAQ analysis. Gene expression profile of CsAPX1 encoding ascorbate peroxidase (APX) was regulated by light/dark conditions. AsA accumulation and APX activity were suppressed by light/dark conditions. SDS-PAGE analysis showed that the molecular mass of recombinant CsAPX1 protein was about 34.45 kDa. Subcellular localization indicated that CsAPX1 protein was a cytosol ascorbate peroxidase. Overexpression CsAPX1 in Arabidopsis indicated that the decrease of AsA content and APX activity in transgenic lines were less significant than that of WT during postharvest storage under light/dark conditions. These data suggested that CsAPX1 involved in regulating AsA metabolism through effecting on the changes of AsA accumulation and APX activity in fresh-cut tea leaves during postharvest storage under light/dark conditions.

Effects of washing and packaging combined treatments on the quality of satsuma mandarins during storage

This study investigated the effects of washing and packaging combined treatments on satsuma mandarin (Citrus unshiu Marc.) quality during storage at 4 °C and 25 °C. The treatments involved the combinations of washing using calcium oxide (CaO, 0.2%) solution, carnauba wax coating with grapefruit seed extract (1%) (CW coating), and modified atmosphere packaging (MAP) using O2–CO2–N2 (9.9%, 2.1%, and 88.0%, respectively). The growth of P. digitatum was inhibited across all samples at 4 °C and 25 °C. CaO washing delayed the increase in mandarin CO2 generation during storage at both temperatures and the decrease in antioxidant capacity at 4 °C. CW coating retarded the increase in CO2 generation and the decrease in firmness and antioxidant capacity at both temperatures. MAP delayed the decrease in ascorbic acid concentration at 25 °C and the increase in CO2 generation at 4 °C and 25 °C and also retarded the reduction in antioxidant capacity with or without CaO washing at both temperatures. The combination of three treatments effectively delayed decreases in firmness, ascorbic acid concentration, and antioxidant capacity, and retarded increases in the CO2 generation of mandarins during storage, which demonstrates the potential effectiveness of combined treatments in extending the shelf life of mandarins.

Evaluation of ascorbic acid content in different varieties of frozen of cherry fruit

Cherry is the most common pit crop in our country. It is zoned in all soil-climatic zones of Ukraine and is a valuable fast-growing fruit breed that gives the fruit essential for human nutrition. It has high flavor qualities, contains 0.70–3.00 % valuable organic acids, 6.5–21.5 % sugar, vitamins, including 13-19 mg/100 g. of vitamin C. The latter plays an important role in human nutrition, since it is essential for normal metabolism. Human body provision with vitamin C (ascorbic acid) is of special concern as 50–80 % of the population manifests its lack, which has a negative effect on human health. Ascorbic acid content in fruit depends on the variety, ripeness degree, soil and climatic conditions of cultivation, harvesting time as well as transportation and storage conditions. Cherry fruit contain within 10−50 mg/100 g of vitamin C. However, the shelf life of cherries is only a few days. Therefore, the annual provision of the population with these fruits is only possible under organization of fresh long-term and canned storage. Freezing is one of the most advanced methods of preservation as it promotes better preservation in the fruit nutritional value, including labile vitamin C, than any other method of processing. Studies have found out that the cherriy fruit lose a significant amount of ascorbic acid during the freezing and in the storage period. The aim of the research was to study the dependence of the characteristics variety and the method of freezing cherry fruit on the change of ascorbic acid content. The fruit of the following cherry varieties were selected for the research in 2016−2018: Zhadana, Chance, Elegant, Optimist, Podbielska, Alpha, Memory of Artemenko grown at the pomology experimental station named after L.P. Symiyenko of IH NAAS. Cherry fruits harvested in the consumer stage of ripeness were sorted, examined, washed, frozen in pre-prepared sugar syrups in plastic cups at a temperature of −22–24 °C, kept at a temperature of −18 °C for up to 6 months. The following variants of fruit freezing were studied: in bulk (control), in 25 % sugar syrup, in 20 % sugar syrup with 4 % ascorutin, in 45 % sugar syrup. Before and after freezing, ascorbic acid content was determined in the fruit for three to six months. Studies on the freezing of cherry fruit were conducted in accordance with the guidelines for conducting research on frozen fruits, berries and vegetables. The chemical composition of the frozen fruit was investigated taking into account the mass losses. According to the research results, the content of ascorbic acid in fresh cherry fruits ranged from 16.25 to 19.15 mg/100 g. The highest content was noted in the cherry varieties of Memory of Artemenko (19.15 mg/100 g), and the lowest – in Optimist (16.25 mg/100 g). In six months following the freezing, compared with fresh fruits, there was a decrease in ascorbic acid by 7–8.85 mg/100 g which made 38.2–51.4 % compared to the fresh fruit. The smallest losses were in the fruits, frozen in 45 % of sugar syrup (35.5–43.2 %) and in 20 % of sugar syrup with 4 % of ascorutin (36.08–44.3 %). Aascorbic acid content at the end of storage was 48.6–553 % in the control and for fruit cherries, frozen in sugar syrups, it was higher and made 53.2–64.5 %. The highest content of ascorbic acid was retained in cherries frozen in 45 % sugar syrup – 56.9–64.5 % and in cherry fruit frozen in 20 % sugar syrup with 4 % ascorutin added – 55.42–63 %. Consequently, there was a decrease in ascorbic acid content by 38.2–51.4 % in the fruits of cherry during the freezing. Somewhat lower was the loss of its content in fruit frozen in sugar syrups, in particular in 45 % of sugar syrup – 35.5–43.2 % and in 20 % of sugar syrup with 4 % of ascorutin – 36.8–44.3 %. In general, the content of ascorbic acid for fruit cherries, frozen in sugar syrups, remained at 53.2–64.5 %. The best preservation of its content in frozen cherry fruits was found in 45 % sugar syrup and 20 % sugar syrup with addition of 4 % ascorutin. Key words: cherry fruit, ascorbic acid, sugar syrup, freezing.

Влияние различных рас дрожжей на качественные показатели и антиоксидантную активность вин из черной смородины

Fermentation is the main technological stage of wine production. The objective of the article is to determine the dependence of qualitative parameters of wine material obtained from blackcurrant on the taken yeast race. The authors studied the influence of yeast on the blackcurrant mash fermentation dynamics, formation of secondary products, content of biologically active substances and antioxidant activity of the obtained wine material. The authors used Saccharomyces of two types: Saccharomyces vini – Chernosmorodinovaya 7, K-17, Moskva 30, Vishnevaya 33, K-72, and Saccharomyces cerevisiae – “Red Fruit”, WET 136, LW 317-29, UWY SP1. Mass fraction of total phenolic compounds content expressed in terms of gallic acid was determined applying spectrophotometric method using Folin-Chokalteuʼs reactant. Mass fraction of ascorbic acid was calculated using high-performance liquid chromatography. The authors measured antioxidant activity applying improved ABTS method on Shimadzu UV-1600 spectrophotometer (Japan). They found out that yeast races Saccharomyces cerevisiae had higher fermentation activity than Russian pure yeast races Saccharomyces vini. Saccharomyces cerevisiae surpassed Saccharomyces vini in sugar utilization and ethanol yield. The article reveals that fermentation with Saccharomyces cerevisiae having high fermentation capacity results in the increase of methanol content by 33–57% and decrease in ascorbic acid concentration by 69–83% compared to the wine base samples obtained using Saccharomyces vini. The authors established that phenolic compound concentration in the wine material depends on the period of contact with yeast and on the applied yeast race. They determined that antioxidant activity of the product mainly depends on ascorbic acid concentration and made a conclusion that yeast race determines product biological value and antioxidant activity substantially. The authors recommend to use Chernosmorodinovaya 7 in high quality blackcurrant wine production.

Effects of glycerol and stearic acid on the performance of chickpea starch-based coatings applied to fresh-cut papaya

ABSTRACTThis study examined the potential of incorporating stearic acid in starch-based edible coating formulations in order to increase the quality and shelf-life of fresh-cut papaya (“Sekaki” variety). Glycerol was employed as plasticizer and stearic acid was incorporated in proportions of; 0 %, 1%, 2%, and 3% (w/w). Film with 30% glycerol, 1% stearic acid, 5 g of starch, and 5% aloe Vera was chosen because it had low film solubility and water vapour permeability (29.54 ± 0.21, 2.99 ± 0.21), respectively. Furthermore, this film had slightly darker L* value (78.19 ± 1.21) which is an advantage because it will be able to reduce the loss of ascorbic acid (AA) which is sensitive to light and acceptable level of mechanical property The properties of the fresh-cut papayas were analysed during 12 days of storage at 10°C. The results obtained showed that the edible coating (i.e. film with 30% glycerol, 1% stearic acid, 5 g of starch, and 5% aloe Vera) significantly improved the physiochemical properties of fresh-cut papaya in terms of reduced weight loss, better firmness, better colour retention, and a slight decrease in AA content during storage. Furthermore, the microbial analysis showed that, the coating was able to extend the shelf life of fresh-cut papaya up to 12 days at refrigerated conditions.

Storability of ‘Tupy’ and ‘Guarani’ blackberries in controlled atmosphere

The aim of this work was to compare the storage potential of ‘Guarani’ and ‘Tupy’ blackberries in controlled atmosphere (CA) and thereafter to determinate the best CA storage conditions for ‘Tupy’ blackberries. Two experiments were carried out. In the first one, ‘Guarani’ and ‘Tupy’ blackberries were stored in CA condition (10 kPa O2 + 15 kPa CO2). We found that ‘Tupy’ blackberry has the best storage potential. Therefore, in the second experiment, several CA conditions were evaluated for ‘Tupy’ blackberries storage, as follows: [1] cold storage (CS): 20.9 kPa O2 + 0.04 kPa CO2; [2] CA with 10 kPa O2 + 15 kPa CO2; [3] CA with 5 kPa O2 + 15 kPa CO2; [4] CA with 10 kPa O2 + 10 kPa CO2. All treatments were stored at 1 °C and 98% (± 1) of relative humidity. The ‘Tupy’ blackberry, despite showing a significant decrease in ascorbic acid content, presented a higher storage potential than ‘Guarani’ blackberry, if stored at recommended CA condition for other cultivars. ‘Tupy’ blackberry stored at 5 kPa O2 + 15 kPa CO2 showed higher ascorbic acid content, soluble solids and titratable acidity as compared to the other storage conditions. In CA with 10 kPa O2 + 15 kPa CO2, the juice was lighter (high L), but differed significantly only from those fruit of CS. The best CA condition for ‘Tupy’ blackberries storage is 5 kPa O2 with 15 kPa CO2.