In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact
Eight wheat products differing in texture (porridge vs. bread), grain fineness (fine, kibbled, intact), and cooking (raw vs. cooked), with pre-measured glycaemic indexes (GI), were analysed by in vitro amylolytic digestion to determine effects of processing to reduce GI on quantities of starch fract...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-06-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/11/13/1904 |
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| author | John Monro Suman Mishra |
| author_facet | John Monro Suman Mishra |
| author_sort | John Monro |
| collection | DOAJ |
| description | Eight wheat products differing in texture (porridge vs. bread), grain fineness (fine, kibbled, intact), and cooking (raw vs. cooked), with pre-measured glycaemic indexes (GI), were analysed by in vitro amylolytic digestion to determine effects of processing to reduce GI on quantities of starch fractions differing in digestibility. The accuracy and precision of the in vitro analysis was assessed from its ability to concurrently predict clinical GI. In porridges, kernel intactness and lack of cooking reduced GI while increasing Type 1 (inaccessible) and Type 2 (ungelatinised) resistant starch. Porridge in vitro GI values (GI<sub>iv</sub>), calculated from the area under in vitro digestion curves minus estimated blood glucose disposal, were: raw fine, 26.3; raw kibbled, 12.6; cooked fine, 63.9; cooked kibbled, 44.1; and correlated closely with clinical GI values (R<sup>2</sup> = 0.97). In bread, the negative association of kernel intactness and resistant starch with GI was seen in vitro but not in vivo. Bread GI<sub>iv</sub> values were: roller milled flour, 67.4; stoneground flour 61.1; kibbled grain, 53.0; kibbled + intact kernel, 49.5; but correlation with clinical values was low (R<sup>2</sup> = 0.47), and variability in the clinical results was high (clinical CV = 72.5%, in vitro CV = 3.7%). Low glycaemic potency of wheat by minimal processing was achieved by maintaining particle size, avoiding hydrothermal treatment, avoiding crushing and using a food matrix requiring little chewing for ingestion. Use of in vitro digestive analysis for high precision measurement of starch fractions with potential secondary health benefits was validated by accurate concurrent prediction of the glycaemic index but needed to account for effects of chewing. |
| first_indexed | 2024-03-09T21:54:16Z |
| format | Article |
| id | doaj.art-e3f9bd5c4d214d119fa5b0e93bdb33c8 |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-09T21:54:16Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foods |
| spelling | doaj.art-e3f9bd5c4d214d119fa5b0e93bdb33c82023-11-23T20:01:13ZengMDPI AGFoods2304-81582022-06-011113190410.3390/foods11131904In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic ImpactJohn Monro0Suman Mishra1The New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New ZealandThe New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North 4442, New ZealandEight wheat products differing in texture (porridge vs. bread), grain fineness (fine, kibbled, intact), and cooking (raw vs. cooked), with pre-measured glycaemic indexes (GI), were analysed by in vitro amylolytic digestion to determine effects of processing to reduce GI on quantities of starch fractions differing in digestibility. The accuracy and precision of the in vitro analysis was assessed from its ability to concurrently predict clinical GI. In porridges, kernel intactness and lack of cooking reduced GI while increasing Type 1 (inaccessible) and Type 2 (ungelatinised) resistant starch. Porridge in vitro GI values (GI<sub>iv</sub>), calculated from the area under in vitro digestion curves minus estimated blood glucose disposal, were: raw fine, 26.3; raw kibbled, 12.6; cooked fine, 63.9; cooked kibbled, 44.1; and correlated closely with clinical GI values (R<sup>2</sup> = 0.97). In bread, the negative association of kernel intactness and resistant starch with GI was seen in vitro but not in vivo. Bread GI<sub>iv</sub> values were: roller milled flour, 67.4; stoneground flour 61.1; kibbled grain, 53.0; kibbled + intact kernel, 49.5; but correlation with clinical values was low (R<sup>2</sup> = 0.47), and variability in the clinical results was high (clinical CV = 72.5%, in vitro CV = 3.7%). Low glycaemic potency of wheat by minimal processing was achieved by maintaining particle size, avoiding hydrothermal treatment, avoiding crushing and using a food matrix requiring little chewing for ingestion. Use of in vitro digestive analysis for high precision measurement of starch fractions with potential secondary health benefits was validated by accurate concurrent prediction of the glycaemic index but needed to account for effects of chewing.https://www.mdpi.com/2304-8158/11/13/1904millingcookingstarch fractionsglycaemic indexprocessing |
| spellingShingle | John Monro Suman Mishra In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact Foods milling cooking starch fractions glycaemic index processing |
| title | In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact |
| title_full | In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact |
| title_fullStr | In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact |
| title_full_unstemmed | In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact |
| title_short | In Vitro Digestive Analysis of Digestible and Resistant Starch Fractions, with Concurrent Glycemic Index Determination, in Whole Grain Wheat Products Minimally Processed for Reduced Glycaemic Impact |
| title_sort | in vitro digestive analysis of digestible and resistant starch fractions with concurrent glycemic index determination in whole grain wheat products minimally processed for reduced glycaemic impact |
| topic | milling cooking starch fractions glycaemic index processing |
| url | https://www.mdpi.com/2304-8158/11/13/1904 |
| work_keys_str_mv | AT johnmonro invitrodigestiveanalysisofdigestibleandresistantstarchfractionswithconcurrentglycemicindexdeterminationinwholegrainwheatproductsminimallyprocessedforreducedglycaemicimpact AT sumanmishra invitrodigestiveanalysisofdigestibleandresistantstarchfractionswithconcurrentglycemicindexdeterminationinwholegrainwheatproductsminimallyprocessedforreducedglycaemicimpact |