The present work aimed to obtain and characterize edible films produced with liquid whey and cassava starch. The films were produced with different proportions of whey (63.75–67.50%) and cassava starch (7.50–11.25%) and characterized in relation to physical, thermal, and microstructural properties. The films showed reduced solubility with increasing concentrations of cassava starch, and those with the highest proportions of whey were more stable to thermal decomposition. The increase in concentration of cassava starch altered the microstructure of the films, making them more irregular and with an accumulation of matter. The production of biodegradable polymer blend films is an important step in the development of films for use in packaging, with the formulation of 67.50/7.50% whey/cassava starch being the best film for continued future work.
: Dehydrated garlic is an importance spice in pre-cooked and processed food products, but studies of the drying variables of this product are scarce. Thus, this work aimed to model and study the kinetics of garlic drying at three different temperatures (40, 50 and 60 °C) and analyze the thermodynamic parameters during the process. The drying was analyzed using pre-established mathematical models for agricultural products and equations that describe the thermodynamics of product dehydration. The best mathematical adjustment for all drying temperatures was the Midilli equation. The moisture ratio was seen to decrease during the process for all situations. The effective diffusivity increased with increasing temperature. The enthalpy change was positive during the process and decreased with increasing temperature. The study entropy was negative, indicating a non-spontaneous reaction. In addition, the Gibbs free energy increased with increasing drying temperature. The thermodynamic standards were satisfactory and correctly described the moisture loss by the garlic samples.
This investigation aimed to assess how the somatic cell count (SCC) impacts milk production and the physicochemical quality of milk, including the effects of centrifugation and microfiltration on SCCs and the yield of fresh cheese. Milk production was analysed at different somatic cell counts (SCCs) to observe how centrifugation and microfiltration affected the removal of SCs from the milk and the yield of fresh cheese. Tukey’s test was employed at a 5% significance level to compare the chemical composition of the milk, milk production, and fresh cheese yield when using microfiltered and/or centrifuged milk. Milk with an SCC of ≤200,000 somatic cells (SCs) per mL exhibited higher yields. Although centrifugation and microfiltration influenced milk fat content, total dry extract and SCC, they did not impact fresh cheese yield. It is important to note that these processes reduced the fat content and SCC, making skim milk a potential option for future research studies.
1 September 2019 in Revista Brasileira de Engenharia Agrícola E Ambiental
The objectives of this study were to fit mathematical models to the experimental data of the drying of the pequi mesocarp, determine the effective diffusion coefficient, and to obtain activation energy and thermodynamic and nutritional properties in different drying conditions. The mesocarp of pequi fruits, with an initial moisture content of 5.05 (decimal, dry basis), was dried in a forced ventilation oven at temperatures of 40, 50, 60 and 70 °C until the final moisture content of 0.15 ± 0.01 (decimal, dry basis). The mathematical models were adjusted by non-linear regression analysis using the Gauss-Newton method, considering the magnitude of the coefficient of determination (R2), the mean relative error (P) and the estimated mean error (SE). Among the models analyzed, the Midilli model presented the best fit. The effective diffusion coefficient increased with increase in temperature, and the activation energy on drying was 11.011 kJ mol-1. The enthalpy decreased with an increase in the drying temperature, while the entropy and Gibbs free energy increased with the drying temperature. The product obtained from drying has low lipid and high carbohydrate concentration, while temperatures above 70 °C could cause denaturation and/or protein complexation. The temperature of 60 °C is most suitable to obtain flour of pequi mesocarp, due to the shorter processing time while maintaining the nutritional quality.
1 January 2019 in Revista Brasileira de Engenharia Agrícola E Ambiental
Baru (Dipteryx alata Vogel) is a native tree of the Cerrado. The drying and milling process can be an alternative for the use and conservation of baru fruits. The objective of this study was to evaluate the effect of drying on the nutritional characteristics of the epicarp + mesocarp flour of baru fruits. The fruits were collected in the municipality of Santa Helena de Goiás, Goiás, sanitized and submitted to drying in an oven with air circulation at temperatures of 40, 60, 80 and 100 ºC until they had a constant mass. The analyses were performed in triplicate and the results evaluated by analysis of variance and Tukey test (p ≤ 0.05). Flours produced from dehydrated fruits had a reduction in lipid content (treatments 100 °C), energy value (60 and 80 °C), pH, soluble solids, apparent specific mass and carotenoids in relation to the control sample, and high values of acidity, antioxidant activity and total phenolics. FTIR analysis showed nutrient loss.