British Journal of Nutrition

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British Journal of Nutrition (2010), 103:1404-1412 Cambridge University Press
Copyright © The Authors 2010
doi:10.1017/S0007114509993321

Full Papers

Metabolism and Metabolic Studies

Digestion rate of dietary starch affects systemic circulation of amino acids in weaned pigs


Fugui Yina1, Zhenzhen Zhanga1a2, Ju Huanga1 and Yulong Yina1a2 c1

a1 Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, CAS, Hunan 410125, China
a2 National Key Laboratory of Food Science and Technology, College of Life Science, Nanchang University, Nanchang, Jiangxi 330047, China
Article author query
yin f [PubMed]  [Google Scholar]
zhang z [PubMed]  [Google Scholar]
huang j [PubMed]  [Google Scholar]
yin y [PubMed]  [Google Scholar]

Abstract

The present study was conducted to evaluate the in vitro and in vivo digestibility of dietary starch and its digestive behaviour on the systemic circulating amino acids (AA) in weaned pigs. Eighteen weanling pigs surgically fitted with a catheter in the jugular vein were randomly assigned to three dietary treatment groups. Sticky rice starch (SRS) was hydrolysed more quickly in vitro (P < 0·05) than maize starch (MS) and resistant starch (RS), and was almost completely hydrolysed within 4 h. The in vivo digestibility of dietary starch in different segments of the small intestine was significantly different. SRS was digested (81·9 %; P < 0·05) in the anterior jejunum, but not more than half of the MS and RS was digested in the same segment of the small intestine. The digestibilities of isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, valine, alanine, aspartate and serine in the SRS group were higher than in the MS group (P < 0·05), and all nutritionally indispensable and dispensable AA in the SRS group were higher when compared with those in the RS group (P < 0·05). The serum concentrations of nutritionally indispensable AA, proline and serine in the three groups were increased to a peak point within 1·5 h postprandially then decreased gradually; however, the time that serum concentrations of alanine, aspartate, glutamate and glycine in each group increased to a peak point was different. The concentrations of nutritionally indispensable AA, including arginine, cystine, histidine, isoleucine, leucine, methionine, phenylalanine, threonine, tryptophan, tyrosine and valine at 09.30 hours and arginine, cystine, histidine, isoleucine, methionine, phenylalanine, threonine, tryptophan, tyrosine and valine at 13.30 hours in the SRS group were higher than in the MS group (P < 0·05); all nutritionally indispensable AA in the SRS group were higher than in the RS group at 09.30 and 13.30 hours (P < 0·05), respectively. We conclude that dietary starches digested rapidly in vitro have higher digestibility in the anterior small intestine of pigs. Diets containing rapidly digestible starch ameliorate the digestive and absorptive function and regulate AA metabolism to beneficially increase the entry of dietary AA into the systemic circulation in pigs.

(Received April 24 2009)

(Revised November 04 2009)

(Accepted November 09 2009)

(Online publication January 27 2010)

Key Words:Digestion rate; Starch; Amino acids; Pigs

Correspondence:

c1 Corresponding author: Dr Yulong Yin, fax +86 731 8461 2685, email yinyulong@isa.ac.cn

Footnotes

Abbreviations: AA, amino acid; MS, maize starch; mTOR, mammalian target of rapamycin; RS, resistant starch; SRS, sticky rice starch


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