Valorization of Cassava By-Products: Cyanide Content and Quality Characteristics of Leaves and Peel

Abstract

Cassava production generates significant amounts of by-products such as leaves and tuber peel. Instead of considering them as waste, valorization aims to find sustainable ways to utilize them. However, the presence of cyanide and insoluble fibers poses a major obstacle to their conversion into valuable products. Therefore, the objective of this study is to investigate the changes in cyanide concentration and quality of cassava leaves after mechanical pressing and in tuber peel after treatment with an enzyme solution. Frozen leaves were screw-pressed into their fractions: juice, and press cake. The results show that the cyanide level in the press cake was reduced to 73.56% and was concentrated by 97.48% in the juice compared to the frozen leaves. However, the crude protein values of the frozen leaves, juice, and press cake did not differ significantly (p > 0.05), and were 27.09%, 25.47%, and 23.82%, respectively. In addition, the results for the peel revealed that pretreatment with Viscozyme® L, which assists in the mechanical peeling of cassava tubers, also contributed to a reduction in cyanide and insoluble fiber in the peel. Cyanide content was lowered by 53.89–58.94% in enzyme-treated peel from all three runs (ETP1-3) when compared to fresh peel (FP), while the reduction was only 8.63% in the control peel (CP) treated with hot water without enzyme solution. The insoluble fibers in cassava peel, such as neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), and crude fiber (CF), were also degraded more effectively after treatment with an enzyme solution than with hot water.

Recent Trends in the Pre-Drying, Drying, and Post-Drying Processes for Cassava Tuber: A Review

“…Additionally, safety risks associated with cassava consumption and the drying process are significant factors that warrant attention. Cassava contains cyanogenic glycosides, primarily linamarin, which can release cyanide upon hydrolysis [ 22 ]. Improper processing and inadequate drying techniques can lead to high cyanide levels in cassava products, posing health risks such as cyanide poisoning [ 23 ].…”

Genome-Wide Association Study Reveals the Genetic Basis of Crude Fiber Components in Brassica napus L. Shoots at Stem Elongation Stage

“…For example, color, texture, taste and smell are sensory qualities, while vitamins, proteins and minerals are features of the nutritional composition of the product. , One of the biggest influences on texture is the insoluble material present in the cell walls, because this largely determines the perception of smoothness and juiciness . The insoluble material forms the crude fiber (CF) content of the cell wall, which can neither be dissolved in water nor fermented by microorganisms in the large intestine and is formed of cellulose (Cel), hemicellulose (Hem) and lignin. , The contents of the different CF components can be expressed by determining the levels of neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL). , In addition, NDF and ADF are used as parameters to evaluate the feed available energy values and digestibility of ruminant feed . Researchers also use ADF and NDF as criteria to evaluate the digestibility of biofuel feedstock, and estimate the Cel and Hem concentrations of feedstock and bioethanol production .…”

“…7,8 The contents of the different CF components can be expressed by determining the levels of neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL). 9,10 In addition, NDF and ADF are used as parameters to evaluate the feed available energy values and digestibility of ruminant feed. 11 Researchers also use ADF and NDF as criteria to evaluate the digestibility of biofuel feedstock, and estimate the Cel and Hem concentrations of feedstock and bioethanol production.…”