PREPARATION AND ISOLATION OF A PROTEIN ISOLATE FROM CUCURBITA FOETIDISSIMA SEED (SQUASH).

Persistent Link:
http://hdl.handle.net/10150/187771
Title:
PREPARATION AND ISOLATION OF A PROTEIN ISOLATE FROM CUCURBITA FOETIDISSIMA SEED (SQUASH).
Author:
HENDERSON, CURTIS WAYNE.
Issue Date:
1984
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The buffalo gourd (Cucurbita foetidissima), a xerophytic gourd indigenous to the southwestern United States, has been touted a potential food source, particularly in arid and semi-arid regions of the world. Protein isolates from seeds of the gourd were prepared according to sophisticated laboratory and rudimentary village procedures. Prior to preparation of the isolates, levels of trypsin inhibitors, lectins, phytates and flatulent oligosaccharides were measured in defatted, hulled seed. These compounds exist, in xerophytic and domestic squashes, in similar or reduced amounts relative to soybean meal and should pose no noxious threat to the food quality of the protein isolates. The efficacy of protein extraction by a monovalent extractant, sodium hydroxide, was compared to a divalent solvent, calcium hydroxide. These species of protein isolates were compared to isolate prepared, in a similar manner, from seeds of Hubbard squash (Cucurbita maxima), a domestic squash. Chemical analyses indicated sodium hydroxide was the most effective extractant, regardless of procedure or species. Protein content was greater in the laboratory procedure, but amino acid levels were comparable in both laboratory and village processes, in both cucurbit species. Lysine and threonine were found to be limiting amino acids in the isolates compared to the FAO provisional pattern. The amino acid patterns of cucurbit protein isolates were comparable to those of sunflower, safflower and flax but inferior to soybean and rapeseed isolates. When the village procedure, sodium hydroxide extraction, was expanded to a large-scale operation, permitting the production of ample quantities of isolate for animal studies, the amino acid profile became more deficient. The large-scale extraction process was less effective in extracting a high quality protein, albeit the protein and fat content were comparable to the small-scale procedure. Biological evaluation, e.g., total weight gain and PER, of these protein isolates revealed the cucurbit protein isolates were minimally effective as a protein source, whether as a supplementation to sorghum and millet diets or as a sole source of protein. Chemical scores support these conclusions.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Cucurbita.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Nutritional Sciences; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Berry, James W.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titlePREPARATION AND ISOLATION OF A PROTEIN ISOLATE FROM CUCURBITA FOETIDISSIMA SEED (SQUASH).en_US
dc.creatorHENDERSON, CURTIS WAYNE.en_US
dc.contributor.authorHENDERSON, CURTIS WAYNE.en_US
dc.date.issued1984en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe buffalo gourd (Cucurbita foetidissima), a xerophytic gourd indigenous to the southwestern United States, has been touted a potential food source, particularly in arid and semi-arid regions of the world. Protein isolates from seeds of the gourd were prepared according to sophisticated laboratory and rudimentary village procedures. Prior to preparation of the isolates, levels of trypsin inhibitors, lectins, phytates and flatulent oligosaccharides were measured in defatted, hulled seed. These compounds exist, in xerophytic and domestic squashes, in similar or reduced amounts relative to soybean meal and should pose no noxious threat to the food quality of the protein isolates. The efficacy of protein extraction by a monovalent extractant, sodium hydroxide, was compared to a divalent solvent, calcium hydroxide. These species of protein isolates were compared to isolate prepared, in a similar manner, from seeds of Hubbard squash (Cucurbita maxima), a domestic squash. Chemical analyses indicated sodium hydroxide was the most effective extractant, regardless of procedure or species. Protein content was greater in the laboratory procedure, but amino acid levels were comparable in both laboratory and village processes, in both cucurbit species. Lysine and threonine were found to be limiting amino acids in the isolates compared to the FAO provisional pattern. The amino acid patterns of cucurbit protein isolates were comparable to those of sunflower, safflower and flax but inferior to soybean and rapeseed isolates. When the village procedure, sodium hydroxide extraction, was expanded to a large-scale operation, permitting the production of ample quantities of isolate for animal studies, the amino acid profile became more deficient. The large-scale extraction process was less effective in extracting a high quality protein, albeit the protein and fat content were comparable to the small-scale procedure. Biological evaluation, e.g., total weight gain and PER, of these protein isolates revealed the cucurbit protein isolates were minimally effective as a protein source, whether as a supplementation to sorghum and millet diets or as a sole source of protein. Chemical scores support these conclusions.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectCucurbita.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineNutritional Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBerry, James W.en_US
dc.contributor.committeememberReid, Bobby L.en_US
dc.identifier.proquest8424925en_US
dc.identifier.oclc691379850en_US
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