RESISTANCE OF THE KIDNEY BEAN RESERVE PROTEIN, PHASEOLIN, TO PROTEOLYSIS IN THE PORCINE DIGESTIVE-TRACT

R BEGBIE, A W ROSS

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18 Citations (Scopus)

Abstract

Phaseolin, the major reserve protein of the seeds of the kidney bean, Phaseolus vulgaris L, was shown to be poorly degraded in the pig small intestine following an initial 7-day exposure to casein-based diets incorporating kidney bean meal. Substantial amounts of large polypeptide fragments, which were recognised by antibodies raised against native phaseolin, were identified in ileal digesta. Little of this immunoreactivity was detected in the faeces of these animals, suggesting that components of the hindgut microflora were able to degrade these fragments further. Prolonged exposure to dietary kidney beans resulted in an increase in the digestibility of phaseolin, suggesting that the small intestine and/or its microflora may possess significant adaptive capacity. In-vitro digestion of purified phaseolin by a sequence of pepsin, trypsin and chymotrypsin yielded products which closely resembled those isolated from the ileal digesta; analysis suggested that degradation of native phaseolin by the major gastrointestinal endopeptidases is restricted to a vulnerable central region of its constituent polypeptides.

Original languageEnglish
Pages (from-to)301-307
Number of pages7
JournalJournal of the Science of Food and Agriculture
Volume61
Issue number3
Publication statusPublished - 1993

Keywords

  • KIDNEY BEANS
  • PHASEOLUS-VULGARIS
  • PHASEOLIN
  • INVIVO DIGESTION
  • INVITRO DEGRADATION
  • IMMUNOELECTROPHORESIS
  • SDS-PAGE
  • MAJOR STORAGE PROTEIN
  • INVITRO ENZYMATIC-HYDROLYSIS
  • NUTRITIONAL IMPLICATIONS
  • VULGARIS L
  • DIGESTIBILITY
  • NITROGEN
  • TOXICITY
  • SEEDS

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