Preparation and Characterization of Protein Isolate from Fresh and Hardened Beans (Phaseolus vulgaris L.)

Abstract

The purpose of the present work was to determine the effect of accelerated hardening of beans on yield and physicochemical, functional, and toxicological properties. Protein isolates were obtained from fresh and hardened common beans (Phaseolusvulgaris L.). Acid treatment was an effective method to produce hardened bean. Protein recovery in the isolation procedure for fresh bean isolate (FBI) was 45.5% and 36.15% for hardened bean isolate (HBI); however, the amount of protein was similar in both isolates. In general, the amino acid pattern was similar in both isolates. Electrophoresis analysis showed that the main protein (phaseolin) remained unchanged during the isolation procedure. HBI showed a decrease in the bands of 14 to 26 kDa corresponding to the phytohemagglutinin group, and this was associated with a 56.6% decrease in the concentration of the trypsin inhibitor (TI). Heat treatment of FBI reduced 89.4% of the TI and the hemagglutining activities, and it was reflected in an adequate weight gain of young animals. FBI showed better functional properties than HBI, and both isolates showed the same amount of flavonoids.

Chemical and Functional Properties of Hard-to-Cook Bean (<i>Phaseolus vulgaris</i>) Protein Concentrate

“…Crude protein content in the HTC bean flour (21.71%)was similar to those reported for HTC of P. vulgaris (21.7%) and P. sativum (21.4%), but lower than this reported for HTC of Vigna unguiculta (25.64%) [16]. Using alkaline extraction and isoelectric precipitation, HTC bean protein concentrate crude protein content (73.03%) was similar to the 71.9% reported by Morales de León et al [5]. However, protein recovery under the studied conditions was 13.65%, much less than the 36.15% reported for HTC bean [5].…”

“…Alkaline extraction is a technological alternative for protein isolation from HTC beans. The concentrated protein has low trypsin inhibitor activity and meets Food and Agriculture Organization recommendations for essential amino acids content in diets for adults, meaning they are potentially useful as a supplementary vegetable protein source in food manufacturing [5].…”

Caracterização de concentrado proteico de feijão comum preto, cultivar Iapar 44, novo e envelhecido

“…No envelhecimento de feijão preto comum das variedades Jamapa e 'kidney' por método químico com tampão acetato 0,1 M e pH 4,0, Morales-De Léon et al (2007) e Kaur e Singh (2007) obtiveram farinhas e isolados proteicos com propriedades funcionais (absorção de água e óleo, propriedades emulsificantes, espumantes e de formação de gel) alteradas em relação às amostras não envelhecidas. A eletroforese de isolados proteicos do feijão comum preto demonstrou diminuição nas bandas de 14 e 26 kDa correspondentes ao grupo da fito-hemaglutinina nas amostras endurecidas, indicando alguma perda ou modificação da proteína.…”

“…Capacidade emulsificante (CE), atividade emulsificante (AE) e estabilidade da emulsão (EE) dos concentrados protéicos de feijão comum controle e armazenados a 41 °C e 75% UR*. funcionalidade e perfil eletroforético podem estar relacionadas a modificações na estrutura ou desnaturação da proteína causadas pela ação do agente utilizado para acelerar o endurecimento (Morales-De Léon et al, 2007).…”

Antioxidant activity ofVigna unguiculataL. walp and hard-to-cookPhaseolus vulgarisL. protein hydrolysates

“…Storage at high temperature and relative humidity increases endogenous protease activity and consequent hydrolysis of P. vulgaris storage protein. This would apparently increase overall protein digestibility, but it also causes increased interactions with digestibility-limiting agents such as high molecular mass tannins, which are 1.64 times greater in HTC P. vulgaris (Morales- De-Leo´n et al 2007). …”