Lysine, tryptophan and amino acid profile of normal maize (Zea mays L.), quality protein maize and wheat (Triticum spp.) flour and blends for "Pan De Sal" making

Date

4-2013

Degree

Bachelor of Science in Agricultural Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Solivas, Josefina L.

Committee Member

Salazar, Artemio A. Hurtada, Wilma A.

Abstract

MAGPANTAY, RUTH BERRY OREIRO, College of Agriculture – College of Arts and Sciences, University of the Philippines Los Baños, April 2013. LYSINE, TRYPTOPHAN AND AMINO ACID PROFILE OF NORMAL MAIZE (Zea mays L.), QUALITY PROTEIN MAIZE AND WHEAT (Triticum spp.) FLOUR AND BLENDS FOR “PAN DE SAL” MAKING Adviser: JOSEFINA L. SOLIVAS, M.Sc. Co-adviser: ARTEMIO M. SALAZAR, Ph.D. The proximate composition, total lysine and total tryptophan contents of quality protein maize (QPM) flours were determined and compared to normal maize flours and wheat flour. QPM cultivars were SYQ 6 (yellow) and IPB Var 6 (white). On the other hand, normal maize cultivars were IPB Var 13 (yellow) and IPB Var 8 (white). Same parameters were studied in normal maize, QPM and wheat flour blends and bread. The effects of variety, baking and proportions on total lysine and total tryptophan contents were determined Spectrophotometric methods involving Ninhydrin color reaction and Acid ninhydrin method were used for quantifying lysine and tryptophan contents respectively. Protein quality of samples was evaluated using corrected amino acid scores. Also, qualitative analysis of the essential amino acids was also performed on flour and bread samples using paper chromatography. Comparable levels of percent crude protein were observed for all test flour and bread samples. However, total lysine content of QPM flours were found to be about 16% and 27% higher than normal maize flours and wheat flour respectively. Also, a significantly higher lysine amino acid score of about 82.23-87.38% were observed for both QPM yellow and white flours compared to normal yellow maize, normal white maize and wheat flours with lysine amino acids score of 46.37-66.72%. Comparison of total lysine contents and lysine amino acid scores of QPM breads to normal maize breads and pure wheat bread also showed similar trends regardless of baking. For total tryptophan content, both QPM yellow and QPM white were found to have comparable levels compared to wheat flour but was about 19% higher than normal maize flours Similar trends were observed for tryptophan amino acid score. Unbaked QPM breads, normal maize breads and pure wheat bread had comparable levels of total tryptophan(0.975-1.230 mg/g) and tryptophan score (54.90-65.98%). On the other hand, baked QPM white breads were found to have comparable levels compared to control (1.562-1.817 mg/g) and higher levels compared to normal maize breads (1.434-1.619 mg/g). Same trend of tryptophan amino acid score was observed for baked breads. Paper chromatography showed that all nine essential amino acids were present in all flour and bread samples. Baked breads had a significantly higher crude protein, lysine, and tryptophan contents compared to flour composites. Also, different proportions of wheat to maize flours generally gave comparable levels of measured parameters. Sensory evaluation test results showed that composite breads from 90:10 up to 70:30 (wheat flour : maize flour) proportions have comparable overall acceptability compared to pure wheat bread.

Language

English

Location

UPLB Main Library Special Collections Section

Call Number

LG 993.5 2013 A13 M34

Document Type

Thesis

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