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Mandalari G, Merali Z, Ryden P, Chessa S, Bisignano C, Barreca D, Bellocco E, Laganà G, Faulks RM, Waldron KW. Durum wheat particle size affects starch and protein digestion in vitro. Eur J Nutr 2016; 57:319-325. [PMID: 27785565 DOI: 10.1007/s00394-016-1321-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 09/29/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE The term bioaccessibility refers to the proportion of a nutrient released from a complex food matrix during digestion and, therefore, becoming potentially available for absorption in the gastrointestinal tract. In the present study, we assessed the starch and protein bioaccessibility from a range of wheat endosperm products differing in particle size. METHODS Five porridge meals (size A, flour, mean particle size 0.11 mm, size B, small, mean particle size 0.38 mm, size C, semolina, mean particle size 1.01 mm, size D, medium, mean particle size 1.44 mm, size E, large, mean particle size 1.95 mm) with theoretically different postprandial glycaemic responses were subjected to oral processing in vitro, followed by simulated gastric and duodenal digestion. RESULTS A significant increase (P < 0.001) in starch degradation was observed in size A (52%) compared with size E (25%). Both sizes C and D gave less, although not significantly, digestible starch (32 and 28%, respectively). The glucose release significantly decreased as the particle size of the meal increased (92.16% detected for size A vs 47.39% for size E). In agreement with starch degradation and glucose release, size A gave the most digestible protein. CONCLUSIONS This data provide further evidence that, by decreasing the size of wheat endosperm, starch release and glycaemic response are enhanced. We also showed that protein bioaccessibility followed a similar trend as for starch digestion. Finally, these results support the hypothesis that different degrees of starch encapsulation elicit different blood glucose responses.
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Affiliation(s)
- Giuseppina Mandalari
- The Model Gut, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.,Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy
| | - Zara Merali
- The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK
| | - Peter Ryden
- The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK
| | - Simona Chessa
- The Model Gut, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK
| | - Carlo Bisignano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy
| | - Davide Barreca
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy
| | - Ersilia Bellocco
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy
| | - Giuseppina Laganà
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy
| | - Richard M Faulks
- The Model Gut, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK
| | - Keith W Waldron
- The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.
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Ratnayake S, Beahan CT, Callahan DL, Bacic A. The reducing end sequence of wheat endosperm cell wall arabinoxylans. Carbohydr Res 2013; 386:23-32. [PMID: 24462668 DOI: 10.1016/j.carres.2013.12.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/11/2013] [Accepted: 12/15/2013] [Indexed: 12/31/2022]
Abstract
Walls from wheat (Triticum aestivum L.) endosperm are composed primarily of hetero-(arabino)xylans (AXs) (70%) and (1→3)(1→4)-β-D-glucans (20%) with minor amounts of cellulose and heteromannans (2% each). To understand the differential solubility properties of the AXs, as well as aspects of their biosynthesis, we are sequencing the xylan backbone and examining the reducing end (RE) sequence(s) of wheat (monocot) AXs. A previous study of grass AXs (switchgrass, rice, Brachypodium, Miscanthus and foxtail millet) concluded that grasses lacked the comparable RE glycosyl sequence (4-β-D-Xylp-(1→4)-β-D-Xylp-(1→3)-α-L-Rhap-(1→2)-α-D-GalpA-(1→4)-D-Xylp) found in dicots and gymnosperms but the actual RE sequence was not determined. Here we report the isolation and structural characterisation of the RE oligosaccharide sequence(s) of wheat endosperm cell wall AXs. Walls were isolated as an alcohol-insoluble residue (AIR) and sequentially extracted with hot water (W-sol Fr) and 1M KOH containing 1% NaBH4 (KOH-sol Fr). Detailed structural analysis of the RE oligosaccharides was performed using a combination of methylation analysis, MALDI-TOF-MS, ESI-QTOF-MS, ESI-MS(n) and enzymic analysis. Analysis of RE oligosaccharides, both 2AB labelled (from W-sol Fr) and glycosyl-alditol (from KOH-sol Fr), revealed that the RE glycosyl sequence of wheat endosperm AX comprises a linear (1→4)-β-D-Xylp backbone which may be mono-substituted with either an α-L-Araf residue at the reducing end β-D-Xylp residue and/or penultimate RE β-D-Xyl residue; β-D-Xylp-(1→4)-[α-L-Araf-(1→3)](+/-)-β-D-Xylp-(1→4)-[α-L-Araf-(1→3)](+/-)-β-D-Xylp and/or an α-D-GlcpA residue at the reducing end β-D-Xylp residue; β-D-Xylp-(1→4)-[α-L-Araf-(1→3)](+/-)-β-D-Xylp-(1→4)-[α-D-GlcAp-(1→2)]-β-D-Xylp. Thus, wheat endosperm AX backbones lacks the RE sequence found in dicot and gymnosperm xylans; a finding consistent with previous reports from other grass species.
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Affiliation(s)
- Sunil Ratnayake
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Cherie T Beahan
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Damien L Callahan
- Metabolomics Australia, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Antony Bacic
- ARC Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia; Metabolomics Australia, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia.
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