Benedito Carlos Benedetti

Alternative sanitization methods for minimally processed lettuce in comparison to sodium hypochlorite

Lettuce is a leafy vegetable widely used in industry for minimally processed products, in which the step of sanitization is the crucial moment for ensuring a safe food for consumption. Chlorinated compounds, mainly sodium hypochlorite, are the most used in Brazil, but the formation of trihalomethanes from this sanitizer is a drawback. Then, the search for alternative methods to sodium hypochlorite has been emerging as a matter of great interest. The suitability of chlorine dioxide (60 mg L−1/10 min), peracetic acid (100 mg L−1/15 min) and ozonated water (1.2 mg L−1 /1 min) as alternative sanitizers to sodium hypochlorite (150 mg L−1 free chlorine/15 min) were evaluated. Minimally processed lettuce washed with tap water for 1 min was used as a control. Microbiological analyses were performed in triplicate, before and after sanitization, and at 3, 6, 9 and 12 days of storage at 2 ± 1 °C with the product packaged on LDPE bags of 60 μm. It was evaluated total coliforms, Escherichia coli, Salmonella spp., psicrotrophic and mesophilic bacteria, yeasts and molds. All samples of minimally processed lettuce showed absence of E. coli and Salmonella spp. The treatments of chlorine dioxide, peracetic acid and ozonated water promoted reduction of 2.5, 1.1 and 0.7 log cycle, respectively, on count of microbial load of minimally processed product and can be used as substitutes for sodium hypochlorite. These alternative compounds promoted a shelf-life of six days to minimally processed lettuce, while the shelf-life with sodium hypochlorite was 12 days.

Estabilidade de repolho minimamente processado sob diferentes sistemas de embalagem

Stability of fresh-cut cabbage packed in low density polyethylene under active modified atmosphere and in expanded polyestyrene trays wrapped with PVC was evaluated. The fresh-cut product was stored for 16 days in a cold room at 5 ± 1 °C and 95 ± 5% RH and in a refrigerated display case similar to those found in grocery stores. The following variables were analyzed: content of oxygen and carbon dioxide inside the package headspace; browning, luminosity, polyphenoloxidase and peroxidase activities, pH, titratable acidity; soluble solids, fresh mass loss, and ascorbic acid content. The stability of fresh-cut cabbage was higher at the temperature of 5 °C compared to those stored in the refrigerated displays. The active modified atmosphere was not effective in extending the shelf life of fresh-cut cabbage compared to other treatments. LDPE packaging was more adequate for fresh-cut cabbage storage. However, PVC wrapping also presented satisfactory effects.

EFEITO DA EMBALAGEM E TEMPERATURA DE ARMAZENAMENTO EM REPOLHO MINIMAMENTE PROCESSADO

The objective of this work was to evaluate the changes in the minimally processed cabbage when stored in different packages and temperatures. The minimum process consisted of selection, classification and refrigeration of the raw material, followed by cutting in slices, rinsed with treated tap water for the elimination of cellular exudates, sanitization in solutions with 150mgL-1 of active chlorine, rinsing, centrifugation, weighing, conditioning in polystyrene expanded trays covered with polyvinyl chloride (PVC), 12µm, and polyethylene terephtalate (PET) packages and stored for 15 days at 0, 5 and 10oC temperatures. Every three days the following analyses where carried out: O2 and CO2 concentrations inside the packages, pH, tritatable acidity, soluble solids and vitamin C in the minimally processed cabbage. It was concluded that the cabbage conditioned in the PVC packages presented lower vitamin C loss during the 15 days of storage at all temperatures. These packages also presented higher concentrations of CO2 and lower of O2 , although within the acceptable levels, guaranteeing larger shelf life to the minimally processed cabbage. The shelf life for the products stored at 0 and 5oC were statistically similar; however at 10oC, it was reduced appreciably, at the level of 5% of probability.

Shelf life of minimally processed pineapples treated with ascorbic and citric acids

Abstract The purpose of this research was to determine the shelf life of minimally processed (MP) ‘Perola’ pineapples treated with ascor -bic acid (AA) and citric acid (CA) based on physical, chemical, sensorial and microbiological attributes. Slices were dipped into drinking water (control) or combined solutions of AA:CA (%) (1.0:0.5 and 1.0:1.0) with sodium hypochlorite (NaClO 20 mg L –1 ) for 30 seconds. The samples were conditioned in polyethylene terephtalate packages and stored at 4±1 °C per 13 days. The low peroxidase activity in the slices treated with antioxidant combinations was related to low pH values observed in these samples. The treatments 1.0:0.5 and 1.0:1.0 (AA:CA, %) favored maintenance of the initial a* values and avoided the pulp browning. The ascorbic acid increased more than double on the 2 nd day in the treated slices. By the 4 th day the CO 2 values suggested a higher respiratory activity in the slices treated with anti-browning compounds. The antioxidant treatments did not produce detectable residual flavors in the MP pineapple. Regardless of microbiological safety during the 13 days of cold storage, the control slices can be kept by 6 days, afterwards the color and dehydration become strong enough to affect the appearance. On the other hand, MP ‘Perola’ pineapples treated with 1.0:0.5 (AA:CA, %) and NaClO (20 mg L

Modificações sensoriais em cenoura minimamente processada e armazenada sob refrigeração

Sensory modifications were evaluated in carrots cv Nantes lightly processed in two kinds of cut (grated and sliced) during the storage under refrigeration. Fresh cut carrots were packed in polyethylene tereftalato (PET) boxes and stored at 7oC for 14 days. The carrots appearance, color, aroma, flavor and texture were evaluated weekly. To obtain the frequency of consumption and preference of kind of cut, samples were offered to people to try. During the storage of both kinds of cut, a reduction in scores for appearance and color occurred, while flavor and texture scores were improved. Fresh cut carrots in the grated form presented better color and appearance than the fresh cut in the sliced form. However, flavor and texture were better in carrots cut in the sliced form. The grated carrots are the most indicated for consumption because appearance is the attribute that causes most impact to consumers, besides the color. The frequency of consumption of fresh cut carrots is increasing gradually and, regarding peoples preference for kind of cut, the consumers opted for grated carrot because of the larger practicability and versatility in use.

Effect of controlled atmosphere on postharvest quality of 'Douradão' peaches

This study was carried out with one of the most important cultivar grown in the State of Sao Paulo, Brazil, which has gained the preference of consumers, due to its sweet taste, intense skin color and large size; however, these fruits are susceptible to chilling injury when cold stored for long periods. The use of controlled atmosphere (CA) with elevated CO 2 and reduced O 2 concentrations prevent the onset of the chilling symptom. Thus, the effect of three different conditions of controlled atmosphere (CA1, CA2, CA3 and Control) was evaluated in order to extend the storage life of ‘Douradao’ peaches. After 14, 21 and 28 days, samples were withdrawn from CA and kept in fresh air at 25 ± 1 °C and 90 ± 5% RH to complete ripening. On the day of removal and after 4 days, were the peaches quality characteristics were evaluated. The results showed that the use of CA during cold storage reduced weight loss and prevented postharvest decay. CA2 and CA3 treatments were effective in keeping good quality of ‘Douradao’ peaches during 28 days of cold storage, the ripe fruits showed reduced incidence of woolliness, adequate juiciness and flesh firmness. CA1 and Control treatments did not present marketable conditions after 14 days of cold storage.

Avaliação de índices de firmeza para abacaxi minimamente processado em fatias tratadas com soluções de sais de cálcio

Fresh-cut sliced fruits and vegetables are ready to eat immediately and their sensorial characteristics should be similar to fresh product. Although most of the studies in this area are focused on vegetables, there is a great market potential for fresh-cut sliced fruits, mainly for those which exhibit some commercialization or preparation difficulties such as pineapple. The objective of this work was to evaluate the effect of 1% and 3% concentrations of calcium salts (chloride, sulphate and lactate) on pH, total soluble solids and firmness values of minimally processed pineapple slices. Two types of indenters and three firmness indexes were investigated aiming to identify the best index. Results showed that calcium sulphate 3% kept average firmness index up to 44.45% higher than the index value of the control. Even though both indenters exhibited similar variability the cylindrical one was able to point out more differences between control and treatments than the cylindrical borer indenter.

Atividade respiratória, produção de etileno e vida útil de repolho (Brassica oleracea, var. capitata) minimamente processado em atmosfera controlada

Com o objetivo de avaliar a atividade respiratoria e a producao de etileno do repolho inteiro e minimamente processado e a vida util do repolho mimimamente processado em atmosfera controlada, realizaram-se dois experimentos em etapas sequenciais. Na primeira etapa, avaliaram-se a atividade respiratoria e a producao de etileno do repolho inteiro e minimamente processado, em sistema fechado, nas temperaturas de 5 oC e 10 oC. Na segunda etapa, avaliou-se a vida util do repolho minimamente processado em atmosfera controlada. O produto foi submetido a fluxo continuo de misturas gasosas ternarias, com concentracoes de 2% a 10% de O2 e de 3% a 10% de CO2, previamente umidificadas, na temperatura de 5 oC por 10 dias. Como controle, foi utilizado o ar atmosferico. A atividade respiratoria do repolho inteiro e minimamente processado, armazenado a 5 oC, foi significativamente menor que a do armazenado a 10 oC, sendo que, em ambas as temperaturas, o repolho minimamente processado foi o que obteve a maior atividade respiratoria com relacao ao repolho inteiro. Nao foi detectada a producao de etileno pelo metodo de analise utilizado. A atmosfera controlada nao prolongou a vida util do repolho minimamente processado nas concentracoes de 2% a 10% de oxigenio e de 3% a 10% de dioxido de carbono.

Características físicas e químicas de morango processado minimamente e conservado sob refrigeração e atmosfera controlada

Recebido para publicacao em 16/7/2007 Aceito para publicacao em 12/2/2008 (001726) 1 Embrapa Agroindustria Tropical, CP 13761, CEP 60511-110, Fortaleza CE, Brasil, E-mail: ingrid@cnpat.embrapa.br 2 Embrapa Agroindustria de Alimentos, Av. das Americas, 29.501, Guaratiba, CEP 23020-470, Rio de Janeiro RJ, Brasil 3 Faculdade de Engenharia Agricola, Universidade Estadual de Campinas – Unicamp, Cidade Universitaria Zeferino Vaz, CP 6011, CEP 13083-875, Campinas SP, Brasil, E-mail: benedeti@agr.unicamp.br 4 Departamento de Ciencia dos Alimentos, Universidade Federal de Lavras – UFLA, Lavras MG, Brasil *A quem a correspondencia deve ser enviada Caracteristicas fisicas e quimicas de morango processado minimamente e conservado sob refrigeracao e atmosfera controladaStrawberries cv. Oso Grande were minimally processed and kept in three different atmospheres: 3% O2 + 10% CO2 (N2 balance), 3% O2 + 15% CO2 (N2 balance) and ambient atmosphere (control), at 5 and 10 oC, during 7 days, with the evaluation of their physical and chemical characteristics during storage. Fruits were evaluated at 0, 3 and 7 days for weight loss, firmness, pH, titratable acidity, soluble solids, sugar content (sucrose, fructose and glucose) and total anthocyanins. Data were subjected to analysis of variance (ANOVA) and means were compared by the Least Significance Difference (LSD) test (5%). It was verified that shifting the temperature from 5 to 10 oC had no significant effect on the physical and chemical variables analyzed. The utilization of atmospheres 3% O2 + 10% CO2 and 3% O2 + 15% CO2 was important for quality maintenance of fresh-cut strawberries. They better preserved firmness in relation to ambient atmosphere, and had a positive effect on the control of fruit weight loss. However, fresh-cut fruits kept under those atmospheres showed a lower content of anthocyanins when compared to fruits stored in ambient conditions.

Avaliação de melão minimamente processado armazenado em diferentes temperaturas e embalagens

/15 min), resfriamento 10oC/24 h, descasque e corte manual (fatia), banho de imersao em solucao de hipoclorito de sodio (40 mg.L-1/30 s), embalagem e armazenamento. Aos 0, 3, 5, 7 e 10 dias de armazenamento foram feitas analises da concentracao de O 2 e CO 2 , firmeza, pH, acidez total titulavel, solidos soluveis totais, acucares totais e redutores e avaliacao sensorial com provadores treinados. Os resultados mostraram que houve diferencas significativas ao longo do armazenamento no teor de O 2 e CO 2 , firmeza, pH, acucares totais e redutores. Quando comparados com os demais tratamentos, as caracteristicas das frutas armazenadas em embalagens de tereftalato de polietileno a 4oC mantiveram- se mais estaveis. Na analise sensorial houve diferenca significativa entre o primeiro dia de analise e os demais, mostrando que o melao minimamente processado diminui sua qualidade sensorial ao longo do tempo. Palavras-chave: melao, processamento minimo, embalagem, armazenamento, analise sensorial. SUMMARY EVALUATION OF MINIMALLY PROCESSED MELON STORED AT DIFFERENT TEMPERATURES AND PACKAGES. The minimally processed products offer several benefits for consumers, such as the reduction of the time for food preparation, the purchase of healthy products with excellent quality and smaller space for their storage. The objective of this work was to evaluate which package (polyethylene terephtalate or expanded polyestiren tray covered with polyvinyl chloride) would be better for the storage of minimally processed melon stored at 4oC and 10oC. The fruits had passed for the minimum process, which consisted in: reception, selection, washing with tap water and with 200 mg.L -1 sodium hypochlorote solution, cooling at 10oC/24h, peeling and manual cut (slice), immersion bath with 40 mg.L -1 sodium hypochlorote solution for 30 s, packing and storage. Analyses of O 2 and CO 2 concentrations, firmness, pH, total acidity, total solid soluble, total and reducing sugars, and sensorial analysis had been made at 0, 3, 5, 7 and 10 days of storage. The results show that there were significant differences during the storage period for O 2 and CO 2 concentration, firmness, pH, total and reducing sugars. The characteristics of the fruits stored in polyethylene terephtalate packages at 4oC remained more steady when compared with the other treatments. In the sensorial analysis it had significant difference between the first day and the others, showing that the minimally processed melon decreases its sensorial quality with the time.