Gisely Luzia Ströher

Optimization conditions of samples saponification for tocopherol analysis

A full factorial design 2(2) (two factors at two levels) with duplicates was performed to investigate the influence of the factors agitation time (2 and 4 h) and the percentage of KOH (60% and 80% w/v) in the saponification of samples for the determination of α, β and γ+δ-tocopherols. The study used samples of peanuts (cultivar armadillo), produced and marketed in Maringá, PR. The factors % KOH and agitation time were significant, and an increase in their values contributed negatively to the responses. The interaction effect was not significant for the response δ-tocopherol, and the contribution of this effect to the other responses was positive, but less than 10%. The ANOVA and response surfaces analysis showed that the most efficient saponification procedure was obtained using a 60% (w/v) solution of KOH and with an agitation time of 2 h.

Study of the mineral nutrients composition of three genotypes of peanuts

Purpose – The purpose of this paper is to determine the effect of the genotype on the mineral composition (Ca, Cu, Fe, Mg, Mn, Se, Zn and K) of peanuts.Design/methodology/approach – Samples of peanut of three genotypes common names cultivar cavalo vermelho (CCV), cultivar cavalo rosa (CCR) and cultivar tatu (CTA) were used. They were grown in the Maringa, Parana State region in the same period and were purchased directly from the producer. About 500 g of each genotype were purchased and divided into five equal parts. Each part was analyzed separately and in triplicate (n=15). Mineral analysis was performed in an atomic absorption spectrophotometer with flame ionization.Findings – Among the analyzed minerals, K occurred in the greatest amount (−600 mg · 100 g−1 of sample), followed by Mg (−250 mg · 100 g−1 of sample), and calcium (−65 mg · 100 g−1 of sample). These values were statistically equal for the investigated genotypes. The iron content varied significantly between samples (from 2.7 to 4.6 mg · 100...

Application of Multivariate Analysis to Assess the Incorporation of Omega-3 Fatty Acid in Gluten-Free Cakes

A complete 22 experimental planning (two factors at two levels) with central point in quintuplicate was used to investigate the influence of the factors: chia and azuki flours on fatty acids composition of gluten-free chocolate cake. Both factors were significant, but chia flour presented greater influence on the results. Increased values of both factors contributed to improve contents of polyunsaturated fatty acids (380.96 g kg-1 of product), mainly n-3 series (70.25 g kg-1 of product), and provided more adequate nutritional indices. The principal component analysis and desirability function indicated the sample with higher level of both factors as the optimal region. This sample showed an increase in contents of alpha-linolenic acid (188.03%) and polyunsaturated fatty acids (18.16%) when compared to control formulation. The addition of chia flour can improve nutritional characteristics of food stuffs such as bakery products, especially their lipid composition.