Cassava Starch/Carboxymethyl Cellulose Edible Coating Added of Tocopherol: A Strategy to Preserve the Oxidative Stability of Brazil Nuts.

The aim was to apply a cassava starch/carboxymethyl cellulose blend-based edible coating added to a tocopherol mix to Brazil nuts and evaluate oxidative levels during storage. The edible coatings were prepared from a cassava starch/carboxymethyl cellulose blend and identified as control B (no soy lecithin and no tocopherol mix), L (with soy lecithin and no tocopherol mix), and LT and LT2 (with soy lecithin and tocopherol mix). In the forming solutions of the coatings, stability, viscosity, pH, and color were analyzed. The Brazil nuts were immersed in the solutions for 30 s, dried at 45 °C, and placed in an incubator at 25 °C. At 1, 7, 15, 30, 45, 60, 90, and 120 days of storage, mass loss, the browning index, conjugated dienes and trienes, the oxidative state by official methods, and the accelerated oxidation index were evaluated. The blend-forming solutions B, L, LT, and LT2 showed non-Newtonian and pseudoplastic behavior, excellent resistance to flow, and stability. The diene, triene, iodine value, peroxide value, p-anisidine value, and total oxidation indices showed that the application of the cassava starch/carboxymethyl cellulose blend-based edible coating added tocopherol mix, LT, and LT2 preserved the Brazil nuts up to 90 days of storage at 25 °C. PCA shows that all coatings applied to Brazil nuts promoted oil preservation in some evaluation periods, especially those added with a tocopherol mix. It is concluded that cassava starch/CMC added tocopherol mix edible coatings have a potential application as active packaging for foods, especially nuts.

Nuclear Magnetic Resonance Approach in Brazil Nut Oil and the Occurrence of Aflatoxins.

Carcinogenic metabolites of fungi such as aflatoxins play a toxic role in some tree nuts and need to be monitored in their by-products, such as oil. In this context, Brazil nut (Bertholletia excelsa) oil, which is a commodity of great economic importance to Brazil, requires attention to monitor the presence of these toxic agents. Therefore, this study aimed to evaluate the presence of aflatoxins in Brazil nut oil and relate it to the presence of fatty acids in the oil as a surveillance tool for food safety. Brazil nut oil samples (n= 25) were acquired in northern Brazil as (a) non-branded products (n= 07) produced by local farmers using artisanal methods from nuts to be discarded by the industry and (b) industrialized products (n= 18). The samples were analyzed for total aflatoxin content by high-performance liquid chromatography and fatty acid content by nuclear magnetic resonance imaging. Seven (28%) samples were positive for the aflatoxin fractions (B1 + B2 + G1 + G2), ranging from undetected (<2.32) to 50.87 µg/kg. Of the aflatoxin positive samples evaluated by NMR analysis, it was not possible to state that the presence of a particular fatty acid can interfere or influence aflatoxin contamination. This was the first study with data on aflatoxin occurrence in Brazil nut oil. Nevertheless, further research is required to relate saturated or unsaturated fatty acid content with aflatoxin levels. We also suggest the implementation of systems to prevent contamination of the raw materials (seed) and detoxification of the oil to guarantee the product's safety and quality.

Potential use of vegetable proteins to reduce Brazil nut oil oxidation in microparticle systems.

Brazil nut oil is mostly composed of unsaturated fatty acids, some of which are associated with decreased incidence of cardiovascular diseases. Vegetable proteins have been increasingly used as wall material for partial replacement of carbohydrates and whey proteins. In order to create an oil preservation method, Brazil nut oil was encapsulated with three different types of vegetable protein concentrates and gum arabic (GA): rice (RPC + GA); pea (PPC + GA); and soy (SPC + GA) .For this purpose, vegetable protein concentrates were characterized, and after the drying process the physicochemical characteristics of the microparticles were evaluated. The most stable emulsion, after seven days of evaluation, was composed of RPC + GA. RPC + GA. This treatment was also more stable based on the shelf life assessments. We concluded that RCP microparticles were the best option for encapsulating Brazil nut oil in comparison with the other particles evaluated. In addition, the product obtained is potentially capable of being included in various processed foods.

Non-thermal combined treatments in the processing of açai (Euterpe oleracea) juice.

Quality parameters of açai juice processed with ultrasound-assisted, ozone and the combined methods were analyzed in this work. Two ultrasound energy densities (350 and 700 J·mL-1) and two ozonization times (5 and 10 min with 1.5 ppm) were analyzed for pure açai juice and 8 different treatments (22 complete factorial). To evaluate the quality parameters of the juice, physical-chemical analyzes such as pH, titratable acidity, cloud value, non-enzymatic browning, rheology, antioxidant activity (DPPH and ABTS), phenolic compounds, anthocyanins, enzymatic activity (peroxidase and polyphenol oxidase) and microbial counts (mesophilic bacteria, molds and yeasts) were conducted. The treatments with ozone were better for microbial inactivation and the ultrasound for enzymatic inactivation. In general, the use of non-thermal methods can be a good alternative for the processing of açai juice.