Total alcoholic acidity and pH tests as quality parameters in stored soybean grains

Abstract

Despite the technology available to agriculture, qualitative and quantitative losses occurring during post-harvest are still not controlled, and stored grains may undergo changes in their composition, due to storage conditions. This study aimed at determining the sensitivity of the alcoholic acidity and pH tests in soybean (GB 874RR cultivar) grains with different quality standards obtained during storage. A completely randomized design, in a 3 x 6 x 5 (3 storage conditions x 6 storage times x 5 methods) factorial scheme, was used. A correlation was observed among pH, total acidity content (r = 0.888) and grain quality parameters. Deterioration was identified based on the total acidity content, showing a high correlation with fungal incidence (r = 0.864), ether extract (r = -0.781) and electrical conductivity (r = 0.923). The use of phenolphthalein as indicator is more sensitive than pH 8.8. Among the pH determination methods, AOAC was the most suitable for assessing the quality loss during storage.

Nutritional and quality changes in piglet concentrate affected by formulation and storage

“…Thus, the maximum decomposition of the lipid components must occur between pH 5.0 to 5.5. Araújo et al (2016) found a high negative correlation (r=-0.781) between the acidity in the soybean and the ether extract content.…”

Grãos de soja submetidos a diferentes condições de armazenamento

“…No ambiente desfavorável houve um crescimento acentuado nos teores desta variável a partir do segundo mês de armazenamento, que possivelmente pode ter ocorrido em função da deterioração dos grãos neste ambiente (Figura 7). O teor de acidez pode ter se elevado devido as porcentagem de grãos com incidência de fungos, como fermentados, ardidos e mofados, presentes neste ambiente (Araujo et al, 2016). Paraginski et al (2015), afirma que os ácidos graxos livres são consequência de atividade fúngica que está associada ao teor de água do grão da soja, onde acima de 14% de umidade ocorre crescimento fúngico e aumento considerável na produção de ácidos.…”