Rheological and microstructural characterization of pea, lentil and almond protein gels

Yavuz, Hakime Gul

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https://hdl.handle.net/2142/106340 Copy

Description

Title

Rheological and microstructural characterization of pea, lentil and almond protein gels

Author(s)

Yavuz, Hakime Gul

Issue Date

2019-11-12

Director of Research (if dissertation) or Advisor (if thesis)

Padua, Graciela W

Department of Study

Food Science & Human Nutrition

Discipline

Food Science & Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Ethanol induced gel
• plant protein
• protein gels
• rheology
• microstructure.

Abstract

Food industry, in general, and the legume industry, in particular, produce large amounts of protein-based byproducts. Legume seeds generally contain 20% to 30% protein. Food proteins are natural food ingredients that can be used as fortifying and structuring agents in a variety of foods. The gelation of proteins (mainly globular proteins) has received considerable attention for some years because of its potential applications in the food industry. Protein gels can be prepared by cross-linking flexible proteins (e.g. gelatin and keratin) or by inducing the formation of protein aggregates of globular proteins (e.g. pea protein, whey proteins, and soy proteins). In this study three different plant proteins were considered, pea, lentil and almond. Pea seeds consists of 30% protein (70-80% globulins), lentil seeds contain 25-30% protein (70% globulins) and almond seeds contain 15-25% proteins (70% globulins). The objectives of this study were (1) to investigate the ethanol-induced gelation behavior of plant proteins and (2) to characterize rheological and microstructural properties of plant protein gels so formed. The effects of protein concentration in the gelling solution (10%, 15% and 20%), ethanol content of the coagulation media (30%, 40%, 50%, 60%, 70% and 80%) and pH (2, 4 and 7) were considered. Plant proteins formed gels immediately upon contact within ethanol. Rheological measurements indicated that higher protein concentration bolsters instant gel formation. Instant gelation was observed for 15% and 20% protein samples and for most of the 10% protein ones. In general, the strongest gels were formed at 20% protein and 30-40% ethanol. Gel behavior was affected by pH. Rheological measurements at pH 2, 4, and 7 indicated that, at 20% protein in the gelling solution and 30% and 40% ethanol in the coagulation solvent, gels formed immediately upon contact with ethanol for the plant proteins studied and the highest gel strength measurements were observed at pH 2. The results of this research indicated that pea, lentil, and almond proteins form instant gels by ethanol-induced gelation. Gel behavior was affected by protein concentration, ethanol content and pH.

Graduation Semester

2019-12

Type of Resource

text

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Copyright 2019 Hakime Yavuz

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