Abstract This study aimed to verify the need for minerals and vitamins to increase the production of cell mass by acetic acid bacteria (AAB) isolated from the vinegar industry (086/06) and standard strain (Acetobacter aceti CCT 2565). Five minerals (Mo, B, Zn, Fe, and Mn) and eight vitamins (p-aminobenzoic acid, thiamine, niacin, pantothenic acid, pyridoxine, biotin, cyanocobalamin, and inositol) were tested in a fractional factorial design. To prepare the inoculum, different compositions of MYP (mannitol, yeast, and peptone) medium were tested. The most adequate medium was mannitol 25 g/L, yeast extract 0.625 g/L, and peptone 0.375 g/L. Through contour curves, it was determined that strain 086/06 needed supplementation with minerals Mo, B and Mn and vitamins p-aminobenzoic acid, pyridoxine and cyanocobalamin. Standard strain CCT 2565 needed supplementation of all minerals and vitamins studied, except inositol. The lower requirement of micronutrients for high cell multiplication of the 086/06 strain may be related to the adaptation of strain 086/06 to industrial production conditions.

Abstract The aim of this study was to obtain an optimized gluten-free cookie formulation using alternative flours. For this, a 22 central composite rotatable design (CCRD), with varying concentrations of millet flour (MF) and chia seeds (CS), on a base of buckwheat flour (BF), was used. Control cookies were elaborated with 100% wheat flour (WF). The cookies were characterized for texture and other physical tests and by scanning electron microscopy of their internal structure. The response surfaces for the quality parameters of the cookies showed that the higher the proportion of MF used in the formulations, the lower the height and the greater the diameter, expansion factor, and hardness of the cookies. The addition of up to 10% CS showed no influence on the responses. The optimum point was defined as that with diameter, expansion factor, thickness, and hardness closer to the control cookie: 7.5% CS, 40% MF, and 52.5% BF. The substitution of wheat flour by buckwheat flour, millet flour, and chia seeds can be considered a suitable alternative for the preparation of gluten-free cookies.

Amido de mandioca modificado com ácido lático e radiação ultravioleta antes da secagem artificial têm mostrado boa capacidade de expansão, a exemplo da encontrada para o polvilho azedo. Neste trabalho, os efeitos do ácido lático e radiação UV sobre as características físico-químicas e estruturais de amidos de mandioca e milho foram investigados. Apenas o amido de mandioca modificado apresentou capacidade de expansão durante o forneamento. Do RVA, redução dos valores de viscosidade, boa estabilidade interna e nenhuma tendência a retrogradação para este amido modificado foi observado. O amido de milho não apresentou qualquer pico de viscosidade após modificação. Não foram observadas diferenças significativas nas propriedades térmicas, determinadas em DSC, entre os amidos nativos e modificados de ambas as fontes. As moléculas de amilopectina e amilose de ambos os amidos modificados mostraram alguma degradação. O peso molecular da amilopectina do amido de mandioca foi mais preservado, enquanto a amilopectina do amido de milho foi mais atacada em todo o grânulo. As cadeias ramificadas longas da amilopectina de mandioca, com DP~37, foram degradadas, enquanto as de milho mantiveram-se inalteradas.

In this work, the effect of lactic acid and UV irradiation on the physicochemical and structural characteristics of cassava and corn starches was evaluated. Only the modified cassava starch presented baking expansion capacity. From RVA, reduction of viscosity values, greater internal stability and none set back for modified cassava starch were observed. Modified corn starch did not show any peak viscosity. There were no significant differences in DSC thermal properties of treated and native starches. Amylopectin and amylose molecules from both the modified starches displayed some degradation. Molecular weight of cassava amylopectin was mostly preserved, whereas corn amylopectin was evenly attacked through the granule. Nevertheless, the B long branched chains of cassava amylopectin, with DP~37, were degraded whereas they were unchanged for corn amylopectin.