Avaliação de métodos de armazenamento a frio para preservação da concentração de ácido cianídrico em amostras da parte aérea da mandioca

Abstract

Cassava is a crop widely used for animal feed in tropical and subtropical regions. In Brazil,cassava cultivation holds great relevance for family farming, serving as a nutritional, economic,and sustainable resource. The aerial part of cassava is often used in animal feeding due to itsnutritional value. However, this fraction contains cyanogenic glycosides, such as linamarin andlotaustralin, which can release hydrogen cyanide (HCN), a highly toxic and volatile compound.Due to limitations in performing immediate field analyses, it is necessary to adopt storagestrategies capable of preserving HCN concentrations close to those found in the fresh plant. Theaim of this study was to evaluate changes in HCN concentration in the aerial part of bittercassava varieties (Manipeba, Urubu, Ceará, Poti Branca) subjected to cold storage methods:refrigerated (24 h) and frozen (-20 ºC; 30 d). A completely randomized design was used in a 4× 3 factorial arrangement (4 varieties × 2 storages methods (refrigerated and frozen) and freshforage), with four replicates per treatment. Means were compared using Tukey’s test at a 5%significance level. There was an effect of storage (P<0.001), variety (P<0.001), and theinteraction between storage × variety (P=0.021) on HCN concentration. The HCNconcentration in fresh samples showed high values in the Manipeba (77.53 mg/kg DM), Ceará(75.14 mg/kg DM), and Poti Branca (72.38 mg/kg DM) varieties. On the other hand, the lowestconcentration was observed in the Urubu variety (50.55 mg/kg DM). Regarding storage, allvarieties showed reductions in HCN content when samples were refrigerated, compared to freshand frozen samples. The Urubu (36.52 mg/kg) and Poti Branca varieties stood out with thelowest levels, lower than those found in the Manipeba (41.30 mg/kg) and Ceará (42.18 mg/kg)varieties. The HCN concentration in frozen samples of Urubu, Manipeba, and Ceará did notdiffer from fresh samples. Freezing proved to be effective in maintaining HCN concentrationsfor up to 30 d.