Iranian Food Science and Technology Research Journal
with the collaboration of Iranian Food Science and Technology Association (IFSTA)

Isolation, Purification and Characterization of Proteins and Peptides from Calabash (Crescentia cujete L.) Fruit Flesh with Antihypertensive and Lipid-Lowering Properties

Articles in Press

Document Type : Research Article-en

Authors

Jeric Villanueva 1
Andres Godwin Sajise 2
Antonio Laurena 3
Mary Ann Torio 4
Veronica Migo 5

1 Philippine Genome Center Program for Agriculture, Livestock, Fisheries and Forestry, Office of the Vice Chancellor for Research and Extension, University of the Philippines Los Baños, College, Laguna, Philippines

2 T. T. Chang Genetic Resources Center, International Rice Research Institute, Los Baños, Laguna, Philippines

3 Institute of Crop Science, College of Agriculture and Food Science, University of the Philippines Los Baños, College, Laguna, Philippines

4 Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Baños, College, Laguna, Philippines

5 Department of Chemical Engineering, College of Engineering and Agro-Industrial Technology, University of the Philippines Los Baños, College, Laguna, Philippines

https://doi.org/10.22067/ifstrj.2026.98929.1580
Abstract
Calabash (Crescentia cujete L.) fruit has increasingly been studied in recent years for its significant contribution to human health and well-being. The reported bioactivities are linked to the presence of phytochemicals such as polyphenols, but little is known about the role of their proteins. This represents a significant gap, as fruits are generally overlooked as sources of proteins compared to legumes and other proteinaceous products, despite their potential functional and therapeutic applications. This study aimed to isolate, purify, and characterize proteins and peptides from calabash fruits, and evaluate their potential antihypertensive and lipid-lowering activities. Proteins were extracted, purified, and characterized through a combination of biochemical techniques such as sodium phosphate buffer extraction, ammonium sulfate precipitation, gel-filtration chromatography, and in vitro biological assays namely pancreatic lipase inhibition, cholesterol micellar solubility inhibition, and angiotensin-converting enzyme (ACE) inhibition assays. Crude protein isolate (CPI) had a protein concentration of 688 µg/mL with observed protein bands at 12.1 kDa to 46.7 kDa. After simulated gastrointestinal digestion, CPI showed average inhibition activities of 76.5% for ACE, 22.3% for pancreatic lipase, and 84.0% for cholesterol micellar solubility, while the 2-h digest of the purified protein fraction showed 73.4%, 44.9%, and 82.2% inhibition, respectively. Proteins and peptides exhibited strong bioactivity, with inhibition responses across all assays approaching those of the assay controls under the tested conditions. This is the first study to demonstrate the bioactive potential of proteins and peptides extracted from C. cujete fruit, providing promising insights into their possible functional properties associated with the preventive management of obesity, cholesterol levels, and hypertension. Further peptide fractionation and sequence identification are needed to confirm the most active components.

Keywords

Antihypertensive
Bioactive peptides
Calabash
Cholesterol micellar
Functional food
Subjects

Authors retain the copyright. This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0)

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Iranian Food Science and Technology Research Journal

Articles in Press, Corrected Proof
Available Online from 24 August 2026

  • Receive Date 25 May 2026
  • Revise Date 29 July 2026
  • Accept Date 19 August 2026
  • First Publish Date 24 August 2026

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