Increase In Soluble Solids Content Research Articles

Fermentation of tender coconut water by probiotic bacteria Bacillus coagulans

Coconut water is currently being considered as an elixir for patients suffering from diseases like dengue and malaria as well as chikungunia to provide hydration properties to the body. It has become a popular beverage for many people owing to its palatability and high mineral content. In this study, the growth, survival and fermentation performance of the probiotic bacterium Bacillus coagulans in coconut water was assessed in order to produce a novel non-dairy, probiotic beverage. The species was characterized on the basis of morphology, physiology and biochemical parameters and its probiotic attributes were assessed. Batch fermentations were carried out for 2 days at a constant 37°C, thereafter the samples were subjected to microbiological and chemical analysis. The results suggested that the specie produced lactic acid and was acid and bile tolerant. The pH and titratable acidity of probiotic fermented coconut water were found to be 4.4 and 0.53 % lactic acid, respectively. The viscosity of fermented coconut water increased significantly from an initial 5.13 mPa.s to 5.35 mPa.s because of the increase in soluble solids content due to exopolysaccharide production by B. coagulans during fermentation. Also, the overall acceptability score of probiotic coconut water was higher than tender coconut water, suggesting its feasibility for use as a probiotic beverage.

Fermentation of tender coconut water by probiotic bacteria Bacillus coagulans

Coconut water is currently being considered as an elixir for patients suffering from diseases like dengue and malaria as well as chikungunia to provide hydration properties to the body. It has become a popular beverage for many people owing to its palatability and high mineral content. In this study, the growth, survival and fermentation performance of the probiotic bacterium Bacillus coagulans in coconut water was assessed in order to produce a novel non-dairy, probiotic beverage. The species was characterized on the basis of morphology, physiology and biochemical parameters and its probiotic attributes were assessed. Batch fermentations were carried out for 2 days at a constant 37°C, thereafter the samples were subjected to microbiological and chemical analysis. The results suggested that the specie produced lactic acid and was acid and bile tolerant. The pH and titratable acidity of probiotic fermented coconut water were found to be 4.4 and 0.53 % lactic acid, respectively. The viscosity of fermented coconut water increased significantly from an initial 5.13 mPa.s to 5.35 mPa.s because of the increase in soluble solids content due to exopolysaccharide production by B. coagulans during fermentation. Also, the overall acceptability score of probiotic coconut water was higher than tender coconut water, suggesting its feasibility for use as a probiotic beverage.

Exogenous Applications of Brassinosteroids Improve Color of Red Table Grape (Vitis vinifera L. Cv. "Redglobe") Berries.

Color and other quality parameters of “Redglobe” grape (Vitis vinifera L.) berries were evaluated after treatment with brassinosteroid (BR) analogs. Three BRs analogs (24-epibrassinolide, Triol, or Lactone) were applied at three concentrations (0.0, 0.4, or 0.8 mg⋅L-1), at the onset of veraison. A commercial formulation (B-2000®) was also applied, at a recommended rate of 0.06 mg⋅L-1. The tested BR analogs were effective improving berry color (evaluated as color index for red grapes, CIRG), increasing the levels of soluble solids and anthocyanins, and changing the types of anthocyanins present without altering other quality and yield parameters. The effects of BR analogs on color enhancement could be explained by an increase in soluble solids content and/or anthocyanin content. Treatment with 24-epibrassinolide (at 0.4 mg⋅L-1) or the commercial formulation tended to favor the production of dihydroxylated anthocyanins, which are responsible for the red and pink colors of grape berries. Results indicate that the use of BRs constitutes a potential tool in the production of table grapes. This is the first report of this enhancement effect in a productive context.

Comparative transcriptome analysis reveals distinct ethylene\u2013independent regulation of ripening in response to low temperature in kiwifruit

BackgroundKiwifruit are classified as climacteric since exogenous ethylene (or its analogue propylene) induces rapid ripening accompanied by ethylene production under positive feedback regulation. However, most of the ripening–associated changes (Phase 1 ripening) in kiwifruit during storage and on–vine occur largely in the absence of any detectable ethylene. This ripening behavior is often attributed to basal levels of system I ethylene, although it is suggested to be modulated by low temperature.ResultsTo elucidate the mechanisms regulating Phase 1 ripening in kiwifruit, a comparative transcriptome analysis using fruit continuously exposed to propylene (at 20 °C), and during storage at 5 °C and 20 °C was conducted. Propylene exposure induced kiwifruit softening, reduction of titratable acidity (TA), increase in soluble solids content (SSC) and ethylene production within 5 days. During storage, softening and reduction of TA occurred faster in fruit at 5 °C compared to 20 °C although no endogenous ethylene production was detected. Transcriptome analysis revealed 3761 ripening–related differentially expressed genes (DEGs), of which 2742 were up–regulated by propylene while 1058 were up–regulated by low temperature. Propylene exclusively up–regulated 2112 DEGs including those associated with ethylene biosynthesis and ripening such as AcACS1, AcACO2, AcPL1, AcXET1, Acβ–GAL, AcAAT, AcERF6 and AcNAC7. Similarly, low temperature exclusively up–regulated 467 DEGS including AcACO3, AcPL2, AcPMEi, AcADH, Acβ–AMY2, AcGA2ox2, AcNAC5 and AcbZIP2 among others. A considerable number of DEGs such as AcPG, AcEXP1, AcXET2, Acβ–AMY1, AcGA2ox1, AcNAC6, AcMADS1 and AcbZIP1 were up–regulated by either propylene or low temperature. Frequent 1–MCP treatments failed to inhibit the accelerated ripening and up–regulation of associated DEGs by low temperature indicating that the changes were independent of ethylene. On–vine kiwifruit ripening proceeded in the absence of any detectable endogenous ethylene production, and coincided with increased expression of low temperature–responsive DEGs as well as the decrease in environmental temperature.ConclusionsThese results indicate that kiwifruit possess both ethylene−dependent and low temperature–modulated ripening mechanisms that are distinct and independent of each other. The current work provides a foundation for elaborating the control of these two ripening mechanisms in kiwifruit.

Thermal properties of fruit fillings as a function of different formulations

Abstract The present study explores the heat-stability and thermo-physical parameters of apple fillings prepared with different amounts of water-binding agents (inulin, pectin and gellan gum), apple puree over a wide range of the total soluble solids content (30–70°Brix) according to a 2 5 experimental design with added central points. Obtained results showed that the thermal properties of apple fillings, as well as their relative bakery index, primarily depended on hydrocolloids (pectin and gellan gum) and total soluble solids in formulations. As expected, the fillings' glass transition temperatures increased with the increase of soluble solids content in the product, indicating higher stability. Separate models were developed for each thermal property as a function of weight fractions of each ingredient from the formulations of analyzed apple fillings (R 2 > 0.95). In addition, a direct correlation between relative bakery index of the analyzed fillings and their temperature of thermal degradation (R 2 = 0.97), as well as thermal resistance (R 2 = 0.94) displayed in the DSC curves, was found. The study highlights the characterization of filling’s thermal properties as a key feature in predicting its stability during processing and storage of real bakery products.

Changes in quality and defense resistance of kiwifruit in response to nitric oxide treatment during storage at room temperature

The effects of nitric oxide (NO) treatment on quality and disease resistance of kiwifruit (Actinidia deliciosa) cv. ‘Bruno’ were investigated after the fruits were immersed in 0.2mM sodium nitroprusside or water (as control) for 10min and then stored at room temperature. NO treatment reduced diseases incidence; delayed the increase in soluble solid content and the loss of vitamin C (Vc); increased the activities phenylalanine ammonialyase (PAL), peroxidase (POD), and β-1,3-glucanase, with accompanying up-regulation of PAL, POD and chitinase (CHT) expression; and elevated the level of total phenolics, flavonoids, hydroxyproline-rich glycoprotein, and lignin during storage. Thus, NO treatment was beneficial to the maintenance of fruit quality and improvement of disease resistance of kiwifruit during storage.

Effect of deficit irrigation and reclaimed water on yield and quality of grapefruits at harvest and postharvest

The aim of our research was to discover the effects of the long-term irrigation with saline reclaimed (RW) and transfer (TW) water and different irrigation strategies: control (C) and regulated deficit irrigation (RDI) on yield and fruit quality of grapefruit at harvest and during cold storage. TW-RDI treatment decreased tree canopy (TC) and crop load, resulting in a 21% reduction of fruit yield. Regarding fruit quality, RW notably decreased peel thickness at harvest (about 8%); however, this difference was not remained during cold storage. Sugar/acid ratio was mainly increased by RDI, but also by RW, due to an important increase in soluble solid content (11% of average value for TW-RDI, RW-C and RW-RDI). In addition, RDI combined with RW, significantly increased the number of fruits in small category 5 at the end of cold storage. Finally, neither ratio yield/TC nor irrigation water productivity were affected by any irrigation treatments.

Nitric oxide alleviates deterioration and preserves antioxidant properties in ‘Tainong’ mango fruit during ripening

We investigated the effects of nitric oxide (NO) on quality, membrane lipid peroxidation, and antioxidant enzymes in mango (Mangifera indica L. cv ‘Tainong’) fruit during ripening. Fruits were treated with 0.25 mmol·L-1 sodium nitroprusside (SNP) by the immersion method and stored at 23°C for 20 days. SNP treatment significantly suppressed the respiration rate, enhanced fruit firmness, and decreased the rot index, peel color index, and weight loss in the fruit. This treatment also slowed the increase in soluble solids content (SSC) while maintaining high levels of titratable acidity (TA), ascorbic acid (AsA), and phenolic compounds. Furthermore, SNP treatment enhanced the antioxidant activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) and reduced the activities of lipoxygenase (LOX) and polyphenol oxidase (PPO) in mango fruit, which was associated with the reduced accumulation of malondialdehyde (MDA), superoxide anion radical (O 2 •- ), and hydrogen peroxide (H2O2) compared with the control. Therefore, the addition of exogenous SNP has the potential for improving quality and prolonging the shelf life of mango fruits by protecting them against oxidative damage caused by ROS during ripening.

Post-harvest Shelf Life Extension and Nutritional Profile of Thompson Seedless Table Grapes Under Calcium Chloride and Modified Atmospheric Storage

Grapes are the fruits with highest rate of phenolic substances among all other fruits and vegetables but due to its enhanced susceptibility to Botrytis cinerea, its postharvest losses are also very high. In a country like Pakistan that has lesser advancement in post-harvest technological skills, a significant segment of this delicate fruit is lost. This study was conducted with an aim to minimize these losses by retaining healthy and attractive nutritional profile. Freshly harvested grapes after being sorted and graded were divided in three lots, two lots were immersed in aqueous solutions of 1% and 2% calcium chloride followed by modified atmosphere storage at 5% CO2 level, and third lot was control sample that was simply dipped in tap water at ambient conditions, 80% relative humidity and 10 ± 1°C temperature was kept same for all three lots. After being analyzed at harvest, stored grapes were then analyzed for total polyphenols, firmness, acidity, total sugars, total soluble solids and total viable count at 4th, 8th and 12th days of storage respectively. Overall results designated that grapes pretreated with 2% CaCl2 stored at 5% CO2 level retained maximum firmness, acidity and phenolic substances with minimum increase in soluble solid contents and significantly reduced incidence of browning caused by gray mold as compared to water washed control sample that was spoiled at the 8th day of storage. Grapes were stored for 12 days and the effect of storage days on differently pretreated samples was analyzed.

Metabolic fingerprinting of must obtained from sun-dried grapes of two indigenous Cypriot cultivars destined for the production of ‘Commandaria’: A protected destignation of origin product

Grapes's sun-dried process is one of the most critical steps in the production of ‘Commandaria’, a dessert wine product that is exclusively produced in Cyprus and derived from must obtained from two indigenous grape cultivars, namely ‘Mavro’ and ‘Xynisteri’. Despite its significant economic importance, no data regarding the primary and secondary metabolites of the aforementioned cultivars exist. Thus, in the current study, the effect of sun drying process on the qualitative attributes and phenolic profile of ‘Mavro’ and ‘Xynisteri’ musts was dissected. Musts were analyzed at harvest and at the end of the sun-drying process that corresponds to ca. 30–40% water loss. Results highlighted significant differences in chemical composition of the must before and after the sun-drying process. Except for the increase of soluble solids content, a significant increment in glucose, fructose, total acidity, total phenols and total flavonoids contents was monitored. Subsequently, forty-two phenolic compounds were identified by LC-DAD-qTOF-MS revealing the polyphenolic fingerprint of the two cultivars. Results also indicated that changes in the phenolic composition of the obtained must are not only correlated with the dehydration effect, but both synthesis or degradation reactions occurred. In particular, the increases in the concentration of hydroxybenzoic acids were higher than the concentration effect for both cultivars. Regarding to hydroxycinnamates, dehydration caused a six-fold increase of hydroxycinnamic acid content in both cultivars. Intriguingly, the concentration of some hydroxycinnamic acids such as caffeic acid dihexoside and fertaric acid isomer went descending. Although the degradation of the internal side of the skin facilitate improved extractability from the skins to the grape pulp and therefore to the grape must, the sun-drying process may also induced stilbene and lignans synthesis production. A significant effect of dehydration on the postharvest biosynthesis of three groups of flavonoids (flavonols, flavan-3-ols, flavanonols), was also observed. This study sheds some light in the substantial changes that occur in specific metabolites during the sun drying process; such metabolites can be considered as potential factors that may determine organoleptic characteristics and biological properties of the end-product.

Postharvest fruit quality and antioxidants of nectarine fruit as influenced by chlorogenic acid

Our object was to learn how the endogenous phenolics may influence fruit postharvest quality and antioxidants. We presented that chlorogenic acid (CHA) could more prominently reduce ethylene production, softening and soluble solids content decreases of nectarine fruit pulp discs than neo-chlorogenic acid, which is another major phenolic compound of nectarine pulp. Thus, nectarine fruit were infiltrated by CHA, followed by storage for up to eight days at 25 °C. Our results showed that the CHA treatment significantly reduced ethylene production, softening, decay rate and malondialdehyde (MDA) accumulation. The ethylene production in fruit treated with CHA (50 mg L−1) was 41.6% of that in control on the 4th day of storage; decay rate or MDA level of the fruit was reduced by CHA for 73% or 33%, respectively comparing to control on the 8th day of storage. Meanwhile, CHA also retarded peel color turning, increase of soluble solids content and decline of titratable acid in the fruit. Total phenolics content and antioxidant property of the fruit were also influenced by CHA. Antioxidant activity, radical scavenging activity and reducing power in the pulp were remarkably enhanced by CHA. These results suggest that CHA can maintain postharvest quality and antioxidant capacity of fruit.

Effects of water stress on processing tomatoes yield, quality and water use efficiency with plastic mulched drip irrigation in sandy soil of the Hetao Irrigation District

Processing tomatoes are major cash crops in the Hetao Irrigation District, Inner Mongolia, China. Conventional irrigation practices have resulted in ecological and environmental problems due to the specific climate and groundwater conditions. Field experiments were conducted to investigate the effects of water stress on processing tomatoes yield, quality, and water use efficiency with plastic mulched drip irrigation in sandy soil of the Hetao Irrigation District. Tomatoes were irrigated at 40%, 60%, 70%, 80% and 100% of crop evapotranspiration (ETc). Results showed that soil water content and salt concentration mainly varied in the upper 60cm soil layer. Dry aboveground biomass and yield increased with increased ETc to 80 or 100%. The highest yield was obtained with 80% ETc treatment both years (70 and 81t/ha). Increasing water stress led to the increase of soluble solids content and Vitamin C. Actual evapotranspiration (ETa) ranged from 188 to 323mm in the two seasons, and increased quadratically when the irrigation depth increased to 80% ETc. The highest water use efficiency (WUE) was found at 60% ETc treatment in 2013 and 80% ETc treatment in 2014. Comprehensive analysis of yield, WUE and ETa, irrigated at 80% ETc was recommended as the optimal irrigation strategy in the sandy soil of the Hetao Irrigation District.

Atmosfera controlada associada ao 1-metilciclopropeno na preservação da qualidade de kiwi ‘tewi’

Resumo O objetivo deste trabalho foi determinar os efeitos de diferentes tecnologias de armazenamento na qualidade físico-química de kiwis da cultivar Tewi. Após a colheita, parte dos frutos foi submetida ao tratamento com 1-metilciclopropeno (1-MCP) e, posteriormente, frutos tratados e não tratados foram submetidos a diferentes condições de armazenamento, conforme segue: armazenamento em temperatura ambiente (20 °C ± 0,5 °C) durante 12 dias; armazenamento refrigerado (0°C ± 0,5°C) com ou sem controle da atmosfera (3 KPa O2 e 5 KPa CO2), e com ou sem absorção de etileno durante dois e quatro meses. Foram avaliadas a firmeza de polpa, o teor de sólidos solúveis e a acidez titulável. Verificou-se que, independentemente da tecnologia de conservação, houve uma diminuição na firmeza de polpa já aos dois meses de armazenamento, sendo a condição atmosfera controlada associada ao uso do 1-MCP a mais eficaz na retenção desse atributo. Frutos mantidos em temperatura ambiente apresentaram relação direta entre a redução da firmeza de polpa e o aumento do índice de sólidos solúveis; no entanto, após o armazenamento, essa relação nem sempre ocorreu. A maior acidez titulável foi verificada em frutos que receberam 1-MCP. Kiwis ‘Tewi’ apresentam bom potencial de conservação, podendo permanecer armazenados por até quatro meses em atmosfera controlada associada ao controle do etileno pelo uso de 1-MCP ou por absorção do etileno.

Effect of CaCl2 Sprays at Different Fruit Development Stages on Postharvest Keeping Quality of “Hayward” Kiwifruit

The postharvest quality attributes of “Hayward” kiwifruit were investigated to find the optimum times and frequencies of calcium chloride (CaCl2) spray. The vines in two different commercial kiwifruit orchards were sprayed with CaCl2 (1.5%) one, two and three times in 35, 85 and 125 days after full bloom (DAFB). Fruits were harvested at the maturity stage and thereafter stored at 0C for 90 days and five additional days under marketing conditions as shelf life. The results showed that with a few exceptions, one time and two times CaCl2 sprays had no significant effect on kiwifruit postharvest quality. Thrice CaCl2 sprays (35 + 85 + 125 DAFB) significantly enhanced fruit Ca concentration and improved fruit quality such as firmness, total soluble solid, titratable acidity, total chlorophyll and carotenoid content, and reduced fruit weight loss and decay incidence during cold storage and shelf life. Overall, it is proposed that thrice CaCl2 (1.5%) spray in “Hayward” kiwifruit orchards could be more appropriate to improve fruit quality and storability. Practical Applications Consumer's acceptance for ripe “Hayward” kiwifruits is influenced by sugar content, sugar-to-acid ratio, green pulp color and the sensory properties such as texture and appearance. During cold storage, many physicochemical changes will occur in kiwifruits such as weight loss, increase in soluble solid contents, decline in ascorbic acid and cell wall degradation, which significantly affect fruit qualities. Softening plays an important role in textural qualities, consumer acceptability, shelf life and postharvest disease resistance. It is significantly influenced by different preharvest factors. Foliar application of CaCl2 has very important role in improving fruit quality. Calcium participates in cross-linking negative charges, especially on the carboxylic residues of pectin, imparting significant structural rigidity to the wall. Therefore, finding the optimum preharvest CaCl2 spraying time and frequency is very important for orchard management.

Crop Load Management and the Market Profitability of ‘Honeycrisp’ Apples

This study assessed the potential impacts on grower profits when the crop load management is not optimal. We used a hedonic pricing model to estimate the relationship between ‘Honeycrisp’ apple (Malus ×domestica) quantities and prices by size category. This information was used to assess potential changes in grower returns as the grower shifts production toward certain size fruit. A grower would realize a loss of $5332/acre if production of size 48 to 88 count per 40-lb box decreased by 5% and size 100 to 163 count/box increased by 5% compared with current ‘Honeycrisp’ size distribution. In addition, we used experimental auctions to estimate consumers’ willingness-to-pay (WTP) for ‘Honeycrisp’ quality characteristics. Apple consumers, in this study, were willing to pay an average of $0.12/lb more for a one-unit increase in soluble solids concentration. A $0.12/lb discount for a decrease in soluble solids content (SSC) would represent a $1362/acre loss. Optimal sizes and SSC estimated in this study are linked with crop loads no larger than seven fruit/cm2 trunk cross-sectional area under Washington state growing conditions. Given the increasing popularity of ‘Honeycrisp’, growers and allied industries should be aware of the importance of preserving the quality of this cultivar to maintain price premiums and thus profit margins.

Lysophosphatidylethanolamine (LPE) Improves Fruit Size, Color, Quality and Phytochemical Contents of Sweet Cherry c.v. ‘0900 Ziraat’

Lysophosphatidylethanolamine (LPE) affects the quality of flowers, fruits, and other horticultural products. Studies have provided evidence that LPE can accelerate ripening of fruits and prolong shelf-life at the same time. In this study, the influence of LPE on anthocyanin accumulation and phytochemical characteristics of sweet cherry was investigated. LPE (10 ㎎·L -1 ) was applied to a commercial sweet cherry c.v. ‘0900 Ziraat’ orchard two and four weeks before harvest for two treatment years (2011 and 2012). Preharvest applications of LPE resulted in significant improvement in both pomological and phytochemical attributes at harvest. LPE treatment led to a 17% increase in fruit weight and a 6% increase in soluble solid content when averaged over two experimental years. Fruit phytochemical content and antioxidant capacity were increased significantly. The average total phenolic content of LPE-treated fruits for the two years was 703 ㎍ gallic acid equivalent (GAE)/g fresh weight (g FW) compared to 569 ㎍ GAE/g FW in the untreated control. Fruits treated with LPE had a 27% and 16% more anthocyanin than the control fruits in 2011 and 2012. Antioxidant capacity of fruits, as measured by TEAC (Trolox equivalent antioxidant capacity) assay, was 12.5 and 11.4 μ㏖ TE/g FW in LPE-treated and untreated control fruits, respectively, when averaged over two experimental years. Our results suggest that preharvest application of LPE may have the potential to increase anthocyanin accumulation, improve fruit quality and enhance phytochemical characteristics of sweet cherries.

CONTROLE DA MATURAÇÃO PRÉ-COLHEITA DE MAÇÃS ‘ROYAL GALA’ PELA INIBIÇÃO DA AÇÃO OU SÍNTESE DO ETILENO

RESUMOO objetivo deste trabalho foi avaliar os efeitos da inibição da ação (pela pulverização de 1-metilciclopropeno em meio aquoso; 1-MCP) e da síntese (pela pulverização de aminoetoxivinilglicina; AVG) do etileno, sobre a maturação pré-colheita de maçãs. Macieiras ‘Royal Gala’ foram pulverizadas com 1-MCP (50 ou 100 mg L-1) em meio aquoso ou com AVG (124 mg L-1), sete e 28 dias antes do ponto de colheita comercial dos frutos, respectivamente. Macieiras não tratadas com 1-MCP nem com AVG foram usadas como testemunha. As maçãs foram colhidas semanalmente, durante cinco semanas, a partir do sétimo dia após a aplicação do 1-MCP, e analisadas quanto à maturação e qualidade, um dia após a colheita. Índices de maturação e qualidade das maçãs, na data em que os frutos atingiram firmeza de 71,1 N, foram estimados por análise de regressão, para cada tratamento. Os tratamentos 1-MCP (50 e 100 mg L-1) e AVG atrasaram a maturação das maçãs, diminuindo as taxas de produção de etileno, degradação do amido, perda de firmeza da polpa e da acidez, amarelecimento da epiderme, acúmulo de sólidos solúveis e desenvolvimento de cor vermelha. O tempo para os frutos atingirem firmeza de polpa de 71,1 N na planta foi retardado em 6 e 12 dias pelo 1-MCP (100 mg L-1) e AVG, respectivamente, em relação à testemunha. Maçãs tratadas com 1-MCP ou com AVG apresentaram índice de iodo-amido, produção de etileno e acidez semelhantes ou menores que maçãs testemunhas, nas datas em que os frutos de todos os tratamentos atingiram a mesma firmeza de 71,1 N. A magnitude do efeito do 1-MCP sobre a firmeza da polpa foi semelhante àquela sobre a produção de etileno e coloração da epiderme, mas sensivelmente menor que aquela sobre a degradação do amido.Os efeitos do AVG sobre a produção de etileno, coloração da epiderme e acidez foram maiores que aqueles sobre a redução da firmeza da polpa. Os resultados mostram que a pulverização de macieiras com 1-MCPem meio aquoso representa um método adicional de manejo da maturação para escalonamento da colheita de maçãs ‘Royal Gala’.

Changes in Vitamin C Content and Soluble Solids of Carrot Content (Daucus Carota L.) During Storage / Zmeny v Obsahu Vitamínu C a Rozpustnej Sušiny Mrkvy (Daucus Carota L.) Počas Skladovania

Abstract The average vitamin C content of fresh carrots was 56 mg.kg-1. Amount of vitamin C was reduced by the length of storage and storage environment. On average, the most significant decrease in vitamin C to 24.4 mg.kg-1 under laboratory conditions was reported after 56 days when stored carrots were packed in plastic box. When stored in a refrigerator, the vitamin C content decreased to 24.7 mg.kg-1 after 126 days of storage in a plastic box. During both experimental periods in laboratory conditions, the most vitamin C was preserved while being wrapped plastic wrap. This way of packaging also enabled relatively long-term preservation of freshness in variety called “Komarno”, which was up to 60 days. The second best option in this respect is the packed carrot in microtene bags. The least convenient was to store the carrots open without packaging. In the case of refrigerated storage, the options of packaging in plastic wrap and microtene bags were also the best. The most significant decline in vitamin C was found in the variant without packaging and in the food box. Average soluble solids (refractometry dry matter) content in fresh roots reached 7.6%. During storage under laboratory conditions, the SS values increased to 14.8% after 14 days when the carrot was stored open without packaging. In the refrigerator, the soluble solids content in carrots increased to 12.7% after 28 days of storage without packaging. Increase in soluble solids content was mainly caused by transpiration process. Under laboratory conditions, evaporation and increase of soluble solids were faster compared to the variants stored in the cooler

Ultrasound-Assisted Chitosan–Surfactant Nanostructure Assemblies: Towards Maintaining Postharvest Quality of Tomatoes

A novel ultrasound-assisted chitosan–surfactant nanostructure assembly was developed to allow better delivery of chitosan particles into intact fruit tissues for extension of postharvest life. Three solutions of 1 % chitosan–surfactant nanostructure assembly with micelle sizes of 400, 600 and 800 nm were prepared and applied as an edible coating on tomatoes. The fruits were stored at 15 ± 2 °C and 70–80 % relative humidity for 20 days. The indicators of tomato ripening, which included loss of firmness, decline of titratable acidity, decline of chlorophyll content and increase in soluble solid content, were delayed in the treated fruits in comparison to the control (p 0.05).

One option for the management of wastewater from tofu production: Freeze concentration in a falling-film system

Tofu whey is a liquid by-product from tofu production. Although it contains oligosaccharides, proteins and isoflavones, which could be isolated and used as ingredients for functional products, it is currently not utilized but disposed as a waste stream. However, when disposed directly to the environment tofu whey can cause bad odours and pollution of the surface and ground water, so that treatment is necessary. The wastewater treatment of industrial tofu production by current technologies is problematic, because of the high expenses and the lack of knowledge about their efficient operation. Hence the need to use alternative technologies such as freeze concentrations. Falling-film freeze concentration tests of tofu whey were carried out on pilot-scale equipment in three stages. The increase in soluble solids content of the tofu whey and the amount and purity of the ice formed were analysed. It was observed that the concentration could be increased by a factor of 8 (from an initial concentration of 1.9°Brix to a final concentration of 15.5°Brix). The electrical conductivity of the tofu whey at the last stage was 6.48mS/cm and the pH was 5.22. The process efficiency was 82.9% at the first stage but dropped to lower values at later stages. Falling film freeze concentration is a promising alternative to recover the solutes retained in the effluent from the tofu industry, reducing its volume and improving environmental management.