Juan Saavedra del Aguila

Quality of minimally processed beet roots stored in different temperatures

ABSTRACT The present work was carried out with the objective to determine the effect of different storage temperature on thequality of beet root minimally processed. Respiratory activity and mass loss were higher in the storage at 15 o C. Nosignificant differences in color, total soluble solids, betacyanin and betaxanthin were observed among treatments.Based on the results obtained, the storage at 0 o C was recommended to storage beet root minimally processed andthat 10 and 15 o C drastically reduced the quality of minimally processed beet roots during storage.Key words: Beta vulgaris L., fresh-cut, betalains, respiratory rate * Auth or for c respondence INTRODUCTION Beet is a root vegetable of the Chenopodiaceaefamily whose edible part is its tuberous root. Itspurple-red color is due to the presence of betalainpigments. These pigments are similar toanthocyanins and flavonoids, which were wronglytermed in the old literature as anthocyaninscontaining nitrogen. Betalains are water-solublepigments and are found only in ten families of theCentrospermae group and are divided into twoclasses: red betacyanin and yellow betaxanthin,which provide beet roots with their typical color(Fenena, 1995). Besides, these pigments oftenexhibit antioxidant activity and potential healthbenefits of vegetables (Kanner et al., 2001).Minimal processing (fresh-cut) comprisesselection, washing, peeling and cutting proceduresthat are aimed at producing a product that is freshand convenient to prepare and consume (Burns,1995). Minimally processed fruits and vegetablesare more perishable than their whole counterparts,due to undergoing severe physical stressesespecially during peeling and cutting procedures.Cutting, associated with high storage temperatures,leads to an increase in the respiratory rate, with anincrease in the activity of enzymes involved inspecific reactions (Chitarra, 1998).Temperature control is the most common andimportant technology to minimize the effects ofcutting in fruits and vegetables (Brecht, 1995).Whole and sliced carrots kept at 0 and 10

Pré-resfriamento em água de lichia 'B3' mantida em armazenamento refrigerado

This project studied the effects of different precooling temperatures and times with water on lychee ‘B3’ fruit quality cold storage. The treatments were: T1 = control (without precooling); T2 = immersed in water at 2.5 o

Effect of antioxidants in fresh cut radishes during the cold storage

The objective of this study was to evaluate the eff iciency of antioxidants in the cold storage of fres h cut radishes. The shredded roots were submerged in the respective treatments during 3 min (ascorbic acid or citric a cid) and stored at 5oC and 90% RH during 10 days. The radish treated with ascorbic acid showed the higher respi ratory rate in the first 4 h after the processing during the storage. The content of total soluble solids (TSS) wa s significantly higher in the treatment with citric acid. There was an increase in the content of ascorbic acid after two day of storage in the treatments with this antioxidant. Th e values of lightness (L*) were decreasing along th e storage. Citric acid treatments caused strongly red colorati on in the minimally processed roots. None of the tr eatments avoided the browning of the shredded radishes durin g the cold storage.

Efeitos de tratamentos térmicos aplicados sobre frutas cítricas armazenadas sob refrigeração

In the present study thermal treatments on,‘Valencia’ orange, ‘Murcott’ tangor and ‘Tahiti’ (temperature conditioning and intermittent warming) were applied lime. The following treatments were applied: T1: Fruits stored at 1°C (Controls); T2: Fast heating of the fruits in hot water at 53°C for 3 minutes and stored at 1°C; T3: Slow heating of the fruits in camera regulated at 37°C for 2 days, with subsequent storage at 1°C; and T4: Intermittent heating in cycles of 6 days at 1°C + 1 day at 25°C. Fruits were stored under low temperature (1°C) and 90-95% relative humidity (RH) during 90 days. Chilling injury incidence and changes in physical-chemical characteristics were evaluated every 15 days. Activity of catalase, glutathione reductase and ascorbate peroxidase was also determined. Intermittent warming was more efficient than temperature conditioning to reduce chilling injury. ‘Tahiti’ lime and ‘Murcott’ tangor supported up to 90 days of intermittent warming stored at 1°C, while control fruits showed chilling injury after 30 days (‘Tahiti’ lime) and 45 days (‘Murcott’ tangor). ‘Valencia’ orange was affected by chilling injury after 45 days of cold storage, and temperature conditioning has caused lower incidence of this disorder. The effect of thermal treatments can be related to the activity of

Pós-colheita de lichia 'Bengal' tratada com etileno e 1-metilciclopropeno

The objective was to determine the physiological and biochemical changes associated with the use of ethylene and 1-methylcyclopropene (1-MCP) on postharvest conservation of lychees as well as the influence of these treatments alone or in combination on skin browning of fruit. After harvest, it was applied the following treatments: without application of 1-MCP or ethylene, ethylene (20mL L-1 for 6 hours), 1-MCP (300nL L-1 for 12h) and ethylene (20mL L-1 for 6 hours) + 1-MCP (300nL L-1 for 6 hours). After treatments, fruits were stored at 5°C and 90% RH for 30 days and were evaluated every 10 days (+3 days of simulated marketing at 25°C and 65% RH). The ethylene production, respiration rate, soluble solids (SS), weight loss, color (lightness - L * and a*) and polyphenoloxidase activity (PPO) were evaluated. Ethylene production and respiration rate showed no significant differences between treatments, and SS decreased over the storage, but there was also no difference between treatments. The enzyme activity showed an increase in PPO, which was correlated to the decreasing rates of L * and a*, occurring in parallel, increased fruit weight loss. It is concluded that the skin browning of lychee is related to weight loss and increased activity of PPO, and that none of the treatments prevented the sking browning of fruit.

Alterações fisiológicas, qualitativas e microbiológicas durante o armazenamento de abóbora minimamente processada em diferentes tipos de corte

The present work was carried out to check the physiological, qualitative and microbiological alterations of minimally processed squash (Cucurbita moschata) cv. Canhao submitted to different cut types (middle-circle, cube and shred). Minimally processed squash was stored at 5oC and 85-90% relative humidity during 12 days. A completely randomized experimental design with four replicates of one package was used. Respiratory rate of the three cuts ranged from 3.2 to 7.5 mL CO2 kg-1 h-1. The cut in cube and shred showed higher ethylene production (4.05 and 3.82 µL C2H4 kg-1 h-1, respectively). The shredded squash showed undesired qualitative alterations, as higher weight loss (2.66%), decrease in soluble solids amount, acid ascorbic and carotenoids. Besides, this cut increased growth of psychotropic bacteria. The cube and middle-circle cuts showed best results in relation to the physical, chemical and physicochemical analysis and psychotropic bacteria amount, when compared to the shred cut. No coliforms or Salmonella growth was observed during storage of the cut types.

Fisiologia de mudas de morangueiro produzidas em sistema convencional e em vasos suspensos

A utilizacao de um sistema adequado para a conducao das plantas-matrizes fornecedoras de mudas e de fundamental importância, tanto com a finalidade de favorecer a quantidade de mudas produzidas, como para a qualidade das mesmas; por outro lado, a disponibilidade de mudas em periodos nao convencionais de plantio, atraves da utilizacao da frigoconservacao, possibilita a producao de frutos na entressafra, propiciando maiores ganhos pelos produtores devido aos melhores precos alcancados. Os presentes trabalhos tiveram como objetivos comparar o sistema de producao de mudas de morangueiro convencional com o de producao em vasos suspensos, assim como avaliar a frigoconservacao em mudas produzidas em sistema de vasos suspensos. Avaliaram-se a materia seca, os teores de carboidratos nas mudas e a percentagem de sobrevivencia das mesmas apos o transplante para local definitivo. No primeiro trabalho, foi utilizado o delineamento inteiramente ao acaso, em esquema fatorial 3x2 (tres cultivares: Campinas, Pelican e Guarani; e dois sistemas de producao de mudas), com tres repeticoes de 30 mudas; no segundo trabalho, utilizou-se o delineamento experimental inteiramente ao acaso, com cinco cultivares (Campinas, Dover, Pelican, Sequoia e Sweet Charlie) e nove repeticoes. Neste ultimo trabalho, apos a coleta, as mudas foram acondicionadas em sacos de polietileno e frigoconservadas durante 120 dias em câmara fria (-1 ± 1oC). As mudas produzidas em vasos suspensos apresentaram maior percentagem de sobrevivencia e maiores teores de carboidratos totais, com resultados semelhantes para as tres cultivares estudadas. A frigoconservacao de mudas de morangueiro produzidas em sistema de vasos suspensos resultou em baixa percentagem de sobrevivencia de mudas no experimento.

Alteração do metabolismo respiratório em rabanetes minimamente processados

The present experiment was aimed at determining the respiratory rate and ethylene production of fresh cut radish and whole radish during cold storage. The rates were evaluated during the first 4 hours after processing and daily, during 10 days at 5°C (± 1°C) and 90% (± 5%) RH. Radishes not processed presented lower respiratory rate (40.61mL CO2 kg-1 h-1) if compared to shredded radishes (93.90mL CO2 kg-1 h-1) 4 hours after processing. Whole and fresh cut radishes showed the highest respiratory rate in the 2nd day of storage with 99.27 and 170.32mL CO2 kg-1 h-1, respectively. On the 10th day of storage, fresh cut radishes showed respiratory rate 149% higher than whole radishes. The minimal processing operations, mainly the cut, enhanced the respiratory rate.

Respiração e produção de etileno em beterrabas inteiras e minimamente processadas submetidas a tratamentos com etileno e biorreguladores

The objective of this work was to evaluate the effects of ethylene and bioregulators on the respiratory activity and ethylene synthesis of minimally processed and whole beet roots. For the minimal processing, beet roots were graded for firmness, color and size, and were peeled. Roots were then sanitized, shredded (2 mm thick), rinsed and centrifuged. The following treatments were applied: ethylene (1000 µL L-1), 1-methylciclopropene (300 nL L-1) and salicylic acid (500 mg L-1). After treatments, beet roots were packed and stored at 5±1 oC and 85±5% RH during 10 days. It was observed that salicylic acid use promoted the decrease of respiratory rates of minimally processed beet roots during all storage time. It was also noted difference between whole and minimally processed beet roots physiology. This difference was observed by the high values of respiratory activity and ethylene production rates in the minimally processed beet roots.