The leaves and stems of Cape gooseberry (Physalis peruviana L.) as an alternative source of bioactive substances

Abstract

Abstract The objective of this work was the investigation of the chemical composition of the leaves and stems of two Cape gooseberry (Physalis peruviana L.) genotypes from Bulgaria (CG-SB and CG-NB), with the view of establishing the presence of certain bioactive substances and the prospects for their use as livestock feed or cosmetic ingredients. The leaves and stems of CG-SB genotype contained 18.63% and 40.26% cellulose, respectively, and 24.83% and 13.73% protein; the respective contents in the leaves and stems of CG-NB genotype were 27.63% and 47.63% cellulose, and 9.36% and 8.07% protein. The dominant amino acids in CG-SB leaves were aspartic acid (32.04 mg.g-1) and lysine (30.54 mg.g-1), and in the stems – proline (46.90 mg.g-1) and phenylalanine (15.42 mg.g-1). The amino acid composition of the leaves of CG-NB genotype was dominated by histidine (24.88 mg.g-1) and proline (21.25 mg.g-1), and that of the stems – by proline (13.38 mg.g-1). The main macro and micro minerals in the leaves and stems of both genotypes were K, Mg and Fe, respectively, but numerical differences were observed on a genotype and plant part basis. The leaves were processed by extraction with n-hexane and the content of volatiles was determined (by GC-MS). A total of 32 components was identified in each of the genotypes. The major volatile in both genotypes was n-pentacosanol, 17.07% in CG-SB and 12.39% in CG-NB; the dominant group of chemicals was that of oxygenated aliphatics, followed by diterpenes. The results from the study provide arguments that the leaves and stems of Cape gooseberry, currently discarded byproducts, could be regarded as alternative sources of bioactive substances.