Ernandes Rodrigues de Alencar

Efficacy of ozone as a fungicidal and detoxifying agent of aflatoxins in peanuts

BACKGROUND Peanut contamination by fungi is a concern of processors and consumers owing to the association of these micro-organisms with quality deterioration and aflatoxin production. In this study the fungicidal and detoxifying effects of ozone on aflatoxins in peanuts was investigated. Peanut kernels were ozonated at concentrations of 13 and 21 mg L⁻¹ for periods of 0, 24, 48, 72 and 96 h. RESULTS Ozone was effective in controlling total fungi and potentially aflatoxigenic species in peanuts, with a reduction in colony-forming units per gram greater than 3 log cycles at the concentration of 21 mg L⁻¹ after 96 h of exposure. A reduction in the percentage of peanuts with internal fungal populations was also observed, particularly after exposure to ozone at 21 mg L⁻¹. A reduction in the concentrations of total aflatoxins and aflatoxin B1 of approximately 30 and 25% respectively was observed for kernels exposed to ozone at 21 mg L⁻¹ for 96 h. CONCLUSION It was concluded that ozone is an important alternative for peanut detoxification because it is effective in controlling potentially aflatoxigenic fungi and also acts in the reduction of aflatoxin levels in kernels.

Qualidade dos grãos de soja armazenados em diferentes condições

This study was conducted to evaluate the quality of soy bean grains stored under different conditions. The grains were harvested with moisture content (m. c.) of about 18.0% w.b. and dried to 11.2, 12.8 and 14.8% w.b. To maintain pre-determined m.c., the grains were stored at the following combinations of temperature and relative humidity: for 11.2%: 20 oC and 61.7%; 30 oC and 67.9%; 40 oC and 69.4%; for 12.8%: 20 oC and 73.7%; 30 oC and 76.7%; 40 oC and 80.8%; and for 14.8%: 20 oC and 82.7%; 30 oC and 83.9%; 40 oC and 85.3%. Grains were sampled every 45 days over 180 days in order to determine m.c., grade classification, apparent specific grain mass, grain color and oil content. In general, the grains deteriorated during the storage period but the quality loss was more accentuated when stored with m.c. of 12.8 and 14.8% at 40 oC. The grains stored with m.c. of 14.8% at 30 and 40 oC did not meet commercial standards after 135 and 90 days, respectively. High m.c. and temperature during storage intensify the deteriorative processes of stored soy bean grains.

Effect of the ozonization process on the quality of peanuts and crude oil

The purpose of this study was to evaluate the effect of ozone on the quality of peanut grains and crude oil extracted from these grains. Peanut samples of 1 kg were used, with a moisture content of 8.0% w.b. and stored in 3 L glass recipients. The ozonization process utilized ozone gas concentrations of 13 and 21 mg L-1, temperature of 25 °C, exposure periods of 0, 24, 48, 72 and 96 h, and a flow rate of 1.0 L min-1. Evaluation of peanut quality consisted of analysis for moisture content, electrical conductivity, lipid concentration and peanut color. The qualitative parameters of the crude oil evaluated were free fatty acids, peroxide index and iodine index. In general there was no alteration in peanut quality due to ozone, except for the coloration of the peanuts. With regard to parameters related to the crude oil extracted from the peanut, there were no qualitative alterations due to ozone exposure. It was concluded that, despite depigmentation of the skin surrounding the peanuts, the quality of the peanuts and the extracted crude oil is not affected by exposure to ozone gas at concentrations up to 21 mg L-1, for up to 96 h.

Influence of soybean storage conditions on crude oil quality

This study was done to evaluate the quality of crude oil from soybeans stored under different conditions. The grains were harvested at 18% (w.b.) moisture content (m.c.), and after drying to 11.2, 12.8 and 14.8% they were stored at 20, 30 or 40 oC. Changes in free fatty acid (FFA) content, peroxide, iodine and photometric color index of the extracted oil were determined at 45-day intervals for 180-day storage. In general, oil FFA content increased in all the samples, except in grains at 11.2% m.c. and stored at 20 oC. The peroxide and photometric color index increased significantly, independently of storage conditions; however, the increase was more accentuated in oil extracted of stored grains at high m.c. and temperature. It was concluded that crude oil quality is not affected during 6-month storage of soybeans up to 15.0% m.c. (w.b.) at 20 oC, and for storage at 30 oC, the grain moisture up to 13% maintains oil quality within the Brazilian market standards.

Postharvest quality of ozonized "nanicão" cv. bananas

This study was done to analyze the physic-chemical, microbiological and sensory qualities of the banana, after being either dry or wet treatment with ozone. For dry processing, the fruits were directly fumigated with ozone for 30 min. The wet treatment included the ozonization of water for 20 min followed by immersion of the fruit in the ozonized water for 10 min. In both treatments, the utilized gas concentration and flow were 0.36 mg L-1 and 1.5 L min-1, respectively. The quality of the fruits was evaluated at the beginning of storage and after 3; 6; 9 and 12 days. The variables analyzed were: fresh mater loss, total titratable acidity, total soluble solids, pH, pulp/peel ratio, color index of the peel, rot severity, microbiological analysis (total fungi and yeast count) and sensorial analysis. In general, the fruits immersed in the ozonized water presented better quality, in reference to both the physico-chemical and microbiological parameters, as well as have good sensory acceptance among those tested. It could therefore be concluded that treatment with ozonized water is a new alternative for the postharvest handling of bananas.

Qualidade de grãos de milho armazenados em silos bolsa

Airtight storage in sealed bags provides an alternative to traditional methods for on-farm grain storage. The objective of this work was therefore to evaluate the quality of corn stored in airtight sealed bags. Grain with moisture content (m.c.) of about 14.5 and 18.0% (w.b.) was properly stored in sealed mini-bags at 25; 30; and 35 °C. Analyses included moisture content, grain classification, apparent specific mass, percentage of germination and electrical conductivity at the beginning of storage and after 30; 60; 90; 135 and 180 days. There was no variation in the moisture content of corn grain stored in the silo bags. Corn was classified as Type 1 during the storage period, except for grain with 18% m.c. at 35 oC. There was no significant decrease in the apparent specific mass in the grain during storage. In general, the percentage of germination decreased in humid and dry corn stored and the electrical conductivity increased in the solution containing the grain, except for grain stored with 14.5% m.c. at 25 and 30 °C. It is therefore possible to store corn grain in silo bags with 14.5% m.c. at 25; 30 and 35 oC for 180 days, and grain with 18% m.c. at 25 and 30 oC for 180 days.

Saturação do ozônio em coluna contendo grãos de amendoim e efeito na qualidade

The objective of this study was to evaluate the ozone saturation process in a column containing peanuts and the effect on product quality. Peanuts with a moisture content of about 6.8% (w.b.) were used, packed in cylindrical PVC containers with 1.10 m in height and 15 cm in diameter. Ozone was injected into the base of the cylindrical column and the corresponding values adopted for the heights of the grain columns were 0.25, 0.50 and 0.75 m. The peanuts were ozonized at concentrations of 1.59 and 2.78 mg L–1, a temperature of 25 °C and a gas flow rate of 5.0 L min–1. The ozone saturation times and concentrations were determined and also the quality of the ozonized peanuts. For peanut kernels ozonated at a concentration of 1.59 mg L–1, saturation times ranging between 222 and 449 min were obtained. Regarding the CSat/C0 ratio, values ​​between 0.32 and 0.48 were obtained. For peanut kernels ozonated at a concentration of 2.78 mg L–1, saturation times between 78 and 251 min were obtained, and the CSat/C0 ratio for an initial concentration of 2.78 mg L-1 was between 0.46 and 0.81. It was concluded from the results that an increase in height of the peanut kernel column resulted in an increased saturation time and decreased saturation concentration. There was no change in product quality during the ozonation process.

Effectiveness of ozone on postharvest conservation of pear (Pyrus communis L.).

The objective of this study was to evaluate the effect of ozone (O3) treatment on postharvest quality of pear cv. ‘Williams’. Pears were exposed to gaseous ozone at the concentration of 100 ppm for 60 minutes in a flow rate of 2.3 L min-1 and stored in BOD incubators at 25 ± 2°C, 75-85 % relative humidity, for 13 days. Fruit quality was evaluated at the beginning and at days 3, 6, 9 and 13 of storage for the following variables: Fresh Mass Loss (FML), Titratable Acidity (TA), Total Soluble Solids (TSS), pH and microbiological examination (total aerobic mesophilic count and total yeast and mold count). The variables Fresh Mass Loss (FML) and Total Soluble Solids (TSS) were significantly affected by the ozone treatment. In general, the microorganism counts in ozonatedpears were lower than those in untreated pears. The treatment with gaseous ozone increased the shelf life of the pears with efficient microorganism control, did not affect the quality parameters pH and titratable acidity and delayed soluble solids increase.

In vitro evaluation of the safety and probiotic and technological potential of Pediococcus pentosaceus isolated from sheep milk

Six isolates (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, and Ac22Pd) of Pediococcus pentosaceus from sheep milk were tested for safety and for probiotic and technological potential. The results showed that none of the isolates were able to produce biogenic amines or virulence factors. The isolates tested showed low hydrophobicities, high auto-aggregation capacities and co-aggregation with L. monocytogenes ATCC 7644, L. sakei ATCC 15521 and E. faecalis ATCC 19444, but none produced β-galactosidase and bacteriocins. The isolates did not show growth at pH values 3 and 12, while in a pH range from 4 to 10 the growth was variable. In the absence of bile, all the isolates showed growth, with suppression at bile concentrations of 0.1%, 0.3%, 0.6% and 1.0%. In the disc-diffusion test, the isolates tested were resistant to oxacillin, sulfatrimethoprim and vancomycin but were sensitive to chloramphenicol and tetracycline. The isolates showed variable responses to penicillin G and were resistant to most of the drugs tested, except for amoxicillin trihydrate and ibuprofen. All cultures showed a high milk-acidification capacity after 24 hours and none produced exopolysaccharides. The isolates of P. pentosaceus were able to produce diacetyl; however, no culture showed extracellular proteolytic activity and the autolysis varied from 21.3% to 30.5% after 24 h. The isolates grew at NaCl concentrations of 4.0 and 6.0%, but the growth was lower at 10.0%. Finally, all the isolates were found to be safe but had limited application as probiotics and in some technological uses.

Characterization of the kefir beverage produced from yam (Colocasia esculenta L.), sesame seed (Sesamum indicum L.) and bean (Phaseolus vulgaris L.) extracts

AbstractThe objective of this study was to evaluate the characteristics of kefir beverages made from yam, sesame and bean extracts after fermentation of the extracts with water kefir grains. Formulations were prepared with raw and boiled yams. To the yam extract, sesame and different percentages of white bean extract were added. The fermentation kinetics, the chemical composition and color of the extracts were analyzed. To determine the fermentation kinetic parameters, pH and titratable acidity were evaluated. The chemical composition and color of all extracts were determined before and after fermentation process. The decrease in pH and increase in titratable acidity were affected both by raw or boiler yam. The addition of bean extract favored the decrease in pH of formulations containing extracts of raw or boiled yams. Chemical composition and color of the beverages were altered after fermentation. The kefir beverage made from yam and sesame enriched with 50% beans proved to be an excellent fermentation substrate. In addition, it is a new way of consuming vegetable products, especially fermented products, which have limited diversity to serve vegan consumers and also people with certain allergies to dairy products.