| 1. |
- Berggren, Anna M., et al.
(author)
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Short‐chain fatty acid content and pH in caecum of rats fed various sources of starch
- 1995
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In: Journal of the Science of Food and Agriculture. - : Wiley. - 0022-5142 .- 1097-0010. ; 68:2, s. 241-248
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Journal article (peer-reviewed)abstract
- Caecal pH and contents of short‐chain fatty acids (SCFA) were registered in rats fed three potential sources of resistant starch (RS); raw pea starch, raw potato starch, and an RS‐enriched preparation obtained from wheat starch by autoclaving and enzymatic incubation. Small intestinal digestibility and delivery of RS to the hind‐gut in the case of raw starches were determined by analysis of faecal starch in animals treated with antibiotics to prevent hind‐gut fermentation. RS content in the RS‐enriched preparation was determined as total starch remaining in an enzymatic gravimetric dietary fibre residue. The fermentability of RS was estimated from the faecal recovery of starch in normal animals with intact hind‐gut microflora. Approximately 35 g per 100 g and 32 g per 100 g were RS in the case of raw potato starch and the RS‐enriched preparation, respectively, versus only 1 g per 100 g in the case of raw pea starch. The caecal pH decreased with all test diets, being most significant with raw potato starch. SCFA production and faecal bulking were negligible with raw pea starch, whereas both raw potato starch and the RS‐enriched preparation significantly increased these parameters. The fermentability of RS in raw potato starch and the RS‐enriched preparation was similar, or about 60–70%. If calculated on basis of fermented amount, RS in raw potato starch was more potent in generating SCFA (49 μmol g−1) than in the RS‐enriched preparation (19 μmol g−1). RS in raw potato starch also displayed the highest faecal bulking capacity. In fact, the faecal dry weight increased more than expected merely from delivery of RS. The relative proportion in caecal contents of acetic‐, propionic‐ and butyric acid was 70, 17 and 8%, respectively, with no significant differences between the three sources of RS.
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| 2. |
- Henningsson, Asa M, et al.
(author)
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Combinations of indigestible carbohydrates affect short-chain fatty acid formation in the hindgut of rats
- 2002
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In: Journal of Nutrition. - : Elsevier BV. - 0022-3166. ; 132:10, s. 104-3098
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Journal article (peer-reviewed)abstract
- The fermentability and pattern of short-chain fatty acids (SCFA) formed in the hindgut of rats given various combinations of dietary fibers (DF) and resistant starch (RS) were investigated. Highly fermentable indigestible carbohydrates, i.e., guar gum (GG), pectin (Pec) and high amylose cornstarch (HAS), and a DF with a relatively high resistance to fermentation, i.e., wheat bran (WB), were included. The substrates were studied individually or as mixtures (GG + Pec, GG + WB and HAS + WB, 1:1, wt/wt indigestible carbohydrate basis) at a total concentration of 100 g indigestible carbohydrates/kg diet and fed to rats for 13 d. Rats fed Pec had a high proportion of acetic acid in the cecum (76 +/- 2% of total SCFA), whereas those fed GG had the highest proportion of propionic acid (31 +/- 4%, P <0.0005). Rats fed GG and Pec had low proportions of butyric acid (6 +/- 1 and 10 +/- 1%, respectively), whereas those fed both had a higher proportion of butyric acid (15 +/- 3%, P < 0.05). Consequently, the cecal butyric acid pool was twice as high in rats fed the GG + Pec mixture (44 +/- 9 micro mol) as in those fed the individual components (19 +/- 2 and 21 +/- 3 micro mol, respectively, P < 0.05). Rats fed HAS with WB had a greater fecal excretion of SCFA (184 +/- 19 micro mol/d) than those fed the individual components (77 +/- 10 and 116 +/- 12 micro mol/d in rats fed HAS and WB, respectively P < 0.05), suggesting that incorporation of WB delayed the site of fermentation of HAS to the distal part of the hindgut. In conclusion, the combination of indigestible carbohydrates may affect both SCFA patterns and the site of SCFA release in the rat hindgut.
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| 3. |
- Svanberg, S. J.Maria, et al.
(author)
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Effects of Boiling and Storage on Dietary Fibre and Digestible Carbohydrates in Various Cultivars of Carrots
- 1997
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In: Journal of the Science of Food and Agriculture. - 0022-5142. ; 73:2, s. 245-254
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Journal article (peer-reviewed)abstract
- The influence of boiling and storage on dietary fibre and digestible carbohydrates was investigated in eight different carrot cultivars. The content of total dietary fibre was in the range 252-291 g kg-1 DW and was generally at the higher end for the early cultivars and at the lower end for the late ones. During storage, there was a decrease in the soluble fibre content in all cultivars and generally an increase in insoluble fibre. Following boiling, the loss of dietary fibre varied considerably between cultivars. After storage, the loss could be correlated to the average root weight of the carrot cultivars. The total content of glucose, fructose and sucrose was rather similar in the various cultivars, whereas their individual distribution differed. Storage had generally minor influence on the sugar content, except in the cultivars Amarant and Bull. On boiling, the loss was solely dependent on the initial sugar concentration. After storage the loss increased, which could be related to the lower dry matter content. The choice of cultivar and storage time is important in interpreting analytical data from carrots and is probably of similar significance in other vegetables when studying effects of heat treatment.
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| 4. |
- Svanberg, S. J.Maria, et al.
(author)
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Molecular Weight Distribution, Measured by HPSEC, and Viscosity of Water-Soluble Dietary Fiber in Carrots following Different Types of Processing
- 1995
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In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 43:10, s. 2692-2697
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Journal article (peer-reviewed)abstract
- The molecular weight distribution, measured by HPSEC, and the viscosity of the water-soluble dietary fiber isolated from variously processed/cooked carrots were investigated. The carrots were studied raw, frozen, blanched, soured, microwaved, and boiled. The fibers were isolated after enzymatic digestion of protein and starch to simulate the situation in the gastrointestinal tract. The degree of polymerization (DP) and the viscosity were highly dependent on the type of processing/cooking and in general followed the degree of heat treatment. Thus, the DP values were similar with raw and frozen carrots, whereas blanched carrots had a lower DP. Further, only minor differences in DP could be observed among blanched, soured, and microwaved material, and the most pronounced degradation was obtained in boiled material. The viscosity was in accordance with the DP measurements and decreased in the order raw > blanched > boiled.
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| 5. |
- Svanberg, S. J.Maria, et al.
(author)
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Physicochemical changes in dietary fiber of green beans after repeated microwave treatments
- 1997
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In: Journal of Food Science. - : Wiley. - 0022-1147 .- 1750-3841. ; 62:5, s. 1006-1010
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Journal article (peer-reviewed)abstract
- The influence of microwave cooking/reheating on dietary fiber in green beans was investigated. The beans were analyzed after blanching and following repeated microwave treatment. Content and composition of dietary fiber as well as molecular weight distribution and viscosity of indigestible water-soluble polysaccharides (WSP) (Mw >1000) were determined. Total fiber content decreased only after the most severe microwave treatment, primarily due to losses of soluble dietary fiber (pectic polymers). Molecular weight and viscosity decreased considerably after the first microwave treatment. Repeated microwave treatments reduced the molecular weight further, but not the viscosity.
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