Cláudio Rosa Gallo

Shelf life of minimally processed carrot and green pepper

As perdas pos-colheita de alimentos horticolas justificam a adocao de tecnicas de conservacao. Uma vez beneficiados, esses produtos permitem agregar valor a producao primaria e se tornam de conveniencia ao consumidor. Este trabalho teve como objetivo definir as metodologias do processamento minimo de cenoura e pimentao quanto ao tipo e intensidade de adocao das tecnicas de barreiras e monitorar os produtos apos o processamento, atraves de analises microbiologica, fisico-quimica e nutricional. As hortalicas foram lavadas e sanificadas com hipoclorito de sodio, 100 mg L-1 de cloro livre, durante 15 min em agua refrigerada (7oC), e a seguir centrifugadas por 5 min. O produto foi acondicionado em sacos plasticos com filme BOPP/PEBD (polipropileno biorientado/polietileno de baixa densidade), selados sob ar atmosferico, vacuo e atmosfera modificada (2% O2, 10% CO2 e 88% N2), e a seguir armazenados a 1oC±1oC. A composicao centesimal das hortalicas permaneceu estavel durante o periodo de armazenamento, nos tres tratamentos testados. Os teores de vitamina C, para as amostras de cenoura e pimentao minimamente processados, nao apresentaram diferencas entre os tratamentos. Os teores de b-caroteno diminuiram ligeiramente durante o periodo de armazenamento para a cenoura e pimentao minimamente processados. Apos o processamento, a cenoura e o pimentao obtiveram contagens para psicrotroficos de 102-105 e 103-106 UFC g-1, respectivamente. Foram constatados anaerobios mesofilos e coliformes totais em pimentoes, da ordem de 1,6x103 a 7,4x105 e <10/g a 7,4x105, respectivamente. Nas cenouras, nao foram detectados coliformes totais e fecais, anaerobios mesofilos e Salmonella em nenhum dos tratamentos. Salmonella nao foi detectada nos pimentoes.

Aspectos fisiológicos e microbiológicos de beterrabas minimamente processadas

The aim of this work was to evaluate physiological and microbiological aspects of fresh cut beet roots. Respiratory activity and ethylene evolution were evaluated during four hours after processing and during the storage period of ten days at 5 o C. Microbiological analysis was carried out right after processing and after ten days of storage. Intact roots showed the lower respiratory activity (5 mL CO 2 kg -1 h -1 ), whereas shredded and peeled beet roots presented a respiration rate of 30 mL CO 2 kg -1 h -1 four hours after processing. Fresh cut beet roots showed a peak during the second storage day (80 mL CO 2 kg -1 h -1 ), reducing to 30 mL CO2 kg -1 h -1 at the fourth day. No ethylene evolution was detected in intact and peeled beet roots whereas in the fresh cut material it was observed in the first hours after processing, reaching 0.90 µL kg -1 h -1 . Few variations were observed during the four-hour period after processing and during the refrigerated storage. Psychotrophic bacteria and total coliforms counts were within acceptable limits, and no Salmonella or fecal coliforms were detected.

Effects of Irradiation and Refrigeration on the Nutrients and Shelf-Life of Tilapia (Oreochromis niloticus)

Abstract The objective of this study was to enhance the shelf life of processed fish, combining ionizing radiation and refrigeration with minimal processing. The physical, chemical, nutritional and microbiological characteristics of the species Tilapia nilotica (Oreochromis niloticus) were studied in eviscerated samples and in commercial cuts. The fish were separated into samples irradiated with 0, 1.0, 2.2 and 5 kGy. They were stored at temperatures ranging from 0.5°C to −2°C for 20 and 30 days. During storage, the level of moisture in the non-irradiated samples decreased and the levels of protein and lipid increased while the irradiated samples remained stable. The levels of TVB-N and NPN increased in the non-irradiated samples but tended to remain stable in the irradiated fish samples. The irradiated samples had a microbiological content below the levels established by the Brazilian seafood legislation, whereas the non-irradiated samples had a higher microbiological content and were not in conformity with the officially permitted levels. The levels of amino acids in muscles and fatty acids in oil remained stable in the irradiated fish stored samples but decreased in the non-irradiated ones. Lipid-oxidation, measured by the TBARS test, showed a tendency to increase when the dose of irradiation increased.

Gamma irradiation in the control of pathogenic bacteria in refrigerated ground chicken meat

ABSTRACT: This work evaluated the effect of gamma radiation on reducting the population of Staphylococcusaureus , Escherichia coli and Salmonella typhimurium in ground chicken breast stored under refrigeration. Theexperiment included a control and 4 doses of gamma radiation (2.0, 4.0, 6.0 and 8.0 kGy) along with 5 periodsof storage under refrigeration (1, 7, 14, 21 and 28 days). Samples of ground chicken breast were inoculatedwith Staphylococcus aureus (ATCC 14458), Escherichia coli (ATCC 11105) and Salmonella typhimurium (ATCC0626), irradiated at temperatures between 4 and 8 o C and stored under refrigeration (5 o C) for 28 days. Theincreased radiation dose and period of storage under refrigeration caused a reduction of Staphylococcus aureus ,Escherichia coli and Salmonella typhimurium populations in the ground chicken breast. Mean radiation D valuesdetermined for Staphylococcus aureus and Escherichia coli were 0.41 and 0.72 kGy, respectively. Gammairradiation was an effective treatment for chicken meat conservation because the radiation dose of 6.0 kGy keptthe ground chicken breast within the microbiological limits established by the Brazilian legislation, for up to 28days under refrigeration.Key words: gamma irradiation, pathogenic bacteria, chicken meat, refrigeration

Efeitos do processamento térmico e da radiação gama na conservação de caldo de cana puro e adicionado de suco de frutas

Sugarcane juice is a very well-known and popular beverage in Brazil, and provided it is properly exploited, it has a high market potential. The aim of this research was to evaluate the physicochemical, microbiological and sensory stability of pure sugarcane juice and mixed with fresh lemon and pineapple juice, subjected to a heat treatment (70 °C/25 min) and/or gamma radiation (2.5 kGy) and stored in high density polyethylene bottles. The data were evaluated by variance analysis and their mean values compared by Tukeys test. Processing of the sugarcane juice reduced the microorganism load without significantly altering the physicochemical composition, aroma and flavor of the beverages in comparison with the control. Luminosity was higher in the product subjected to the heat treatment combined with gamma radiation than that resulting from the other treatments. The polyphenol oxidase activity in the processed beverages was significantly lower than in the control. The addition of fruit juice to the sugarcane juice did not modify the latters physicochemical composition. However, the addition of 10% pineapple juice to the sugarcane juice increased the manganese and reduced sugars content when compared with pure sugarcane juice and with sugarcane juice mixed with 4% lemon juice.

Conservação de melão rendilhado minimamente processado sob atmosfera modificada ativa

Net melons cv. Bonus II were minimally processed as cubes, wrapped in several packaging materials with injection of the gaseous mixture (5% O2 + 20% CO2 + 75% N2) and stored at 3oC for 12 days. The packaging materials were: BB-200: Cryovac multlayer film 65mm; PBC: Probag Conservax polyolephinic film 64µm; PP: polypropylene film 52µm. Polystyrene trays were used as control with perforated cover. Gaseous composition inside of the packaging, microbiological, sensorial and physical-chemical characteristics were determined each 3 days. The gas permeability was determined for each film. BB-200 packaging promoted CO2 accumulation until 24% and O2 reduction until 0,4%. Inside PBC packaging the O2 concentration stabilized at 8% and CO2 about 4%, while inside PP packaging the gaseous concentration stabilized near 13% for O2 and 6% for CO2. In a general sense, physical-chemical and sensorial characteristics were not influenced by the treatments. The modified atmosphere packaging was efficient for the microorganism control. The melon without modified atmosphere packaging showed levels over 105 NMP/g, of mesophilics bacteria, wich pathogenic microorganisms risks and/or deteriorative microorganisms, after 9th storage day.

Monitoring the sardine (Sardinella brasiliensis) fermentation process to obtain anchovies

Anchovies are traditional fish preserves, prepared from fermented fish of the engraulidae family, mainly in European countries. In Brazil, sardines (Sardinella brasiliensis) are an alternative fish for preparing these types of preserves, provided that the preservation process results in a high quality product. In this research, sardines were prepared for preservation and physicochemical, microbiological and sensory analyses were carried out during the preservation process. Whole or eviscerated sardines, with or without condiments/preservatives and with 20% of salt (w/w) were used. Sardines were analyzed fresh, and at 1, 15, 30, 45 and 60 days along the preservation process. The use of whole sardines, with or without condiments/preservatives, presented best results, with increased non-proteic nitrogen in the dry matter, higher levels of total volatile bases and higher contents of lactic acid and sodium chloride. The higher acidity observed in the whole sardine treatments resulted in better control of halophylic mesophilic microorganisms, which were kept under 1.4 x 103 CFU g-1 in both treatments. Total coliforms and Staphylococcus aureus reached 21 and 3.0 x 102 CFU g-1, respectively. Escherichia coli and Salmonella spp were not present in the fresh sardines or in any of the four treatments, indicating that the concentration of salt used was appropriate to maintain the product under adequate microbiological control. Both whole or eviscerated sardines under the conditions of this experiment were appropriate in terms of the microbiological safety of the preserves. Treatments using whole fish, either with or without condiments/preservatives, also presented better sensorial properties such as color, flavor, taste and texture, as compared to the eviscerated fish treatments. Whole sardines produced good quality, anchovy-type preserves, which can be used for consumption and marketing purposes.

IDENTIFICAÇÃO DE LEVEDURAS NO PROCESSO DE FERMENTAÇÃO ALCOÓLICA EM USINA DO ESTADO DE SÃO PAULO, BRASIL

The aim of this research was the evaluation of yeast species present in the fermentation process for alcohol production. Yeast identification was carried out during a semester in the cropping season of 94/95 in the Usina da Pedra at Serrana - SP . Samples of primary juice, must and yeast cream were monthly collected. The identification of isolated yeasts was carried out according to numerical taxonomy proposed by Griffiths (1981) and 72 yeast species, belonging to 5 genera, were identified. The Saccharomyces cerevisiae species: S. uvarum (S. cerevisiae) was the dominant yeast in the sugar cane industry unit studied, and the Saccharomyces genus, was the dominant one.

Efeito do cloreto de cálcio e da película de alginato de sódio na conservação de laranja 'Pera' minimamente processada

The aim of this study was to assess the effect of a calcium chloride solution and a film of sodium alginate on the conservation of minimally processed ‘Pera’ oranges. The quality of minimally processed orange submitted to treatments with 1% calcium chloride and 1% sodium alginate and the control (without treatment application) were monitored by physical, chemical, microbiological, and sensorial analyses every 3 days during storage at 5 °C for a period of 12 days. Treatment with sodium alginate (1%) showed loss of smaller mass over the period of storage; however, the quality of the samples subjected to this treatment was compromised regarding the contents of ascorbic acid, sugars, soluble solids, and firmness. At the end of the storage period, the treatment with calcium chloride (1%) showed the best performance in maintaining the initial characteristics of the fruit preserving the contents of ascorbic acid, acidity, ‘ratio’, sugars, and firmness evidenced by the lower pectin solubilization. The microbiological analysis found negligible values of psycrotrophic bacteria, yeasts, molds, and total coliforms in all treatments. This indicates that a control of hygienic conditions led to a standard microbiological product according to the food legislation without Salmonella and coliforms under 45 °C. Sensorially, minimally processed orange treated with calcium chloride (1%) and control proved good for consumption for up to nine days of storage.

Efeito do momento de sanitização sobre atributos fisico-químicos e microbiológicos de beterrabas minimamente processadas

Early Wonder beet roots were minimally processed and submitted to sanitization treatments: control (no sanitization); sanitization after cutting (standard); sanitization before peeling and after cutting; sanitization only after peeling; sanitization before and after peeling; sanitization before and after peeling and after cut. After the treatments, the product was placed on trays wrapped in PVC film and stored at 5±1°C and 85±5% RH for 10 days. Physicochemical and microbiological analyses were conducted during refrigerated storage. Fecal coliforms and Salmonella were not detected in beet roots that underwent sanitization. Total coliforms and psychotropic bacteria counts, as well as betacyanin and betaxanthin amounts were higher in non-sanitized beet roots. There was a decrease in pigment amounts during storage. Post-peeling sanitization is the most suitable for quality maintenance, as it reduces pigment loss, ensures good food safety standards and avoids chlorine waste.