Effects of different food ingredients and additives on the digestibility of extruded and roller-dried maize starch and its application in low glycemic index nutritional formula powder.

BACKGROUND: Complex interactions that occur among starch, protein, and fat during food processing affect the taste, texture, and digestibility of starch-based food. The physicochemical properties of starch, in particular its slow digestibility, are greatly influenced by processing techniques such as extrusion and roller-drying. This study investigated the effects of various food ingredients and additives on the digestion properties of maize starch treated with extrusion and roller drying. It designed a nutritional formula to develop low glycemic index products. RESULTS: The extruded group containing raw maize starch, soybean protein isolate, soybean oil, lecithin and microcrystalline cellulose in the ratio of 580:250:58:20:3 had the best slow digestion properties. Nutritional formulas were designed at the above ratio, with supplements including calcium casein peptide, multi-vitamins, sodium ascorbate, fructooligosaccharides, xylitol, and peanut meal. The sample containing 10% peanut meal and a 1:3 ratio of fructooligosaccharides and xylitol additions obtained the highest sensory evaluation scores. An obvious slow digestion effect was observed in samples produced from the optimal formula. CONCLUSION: The results of the present study could contribute to the development and production of a low glycemic index, nutritional powder. © 2023 Society of Chemical Industry.

New cultive medium for bioconversion of C5 fraction from sugarcane bagasse using rice bran extract

The use of hemicellulosic hydrolysates in bioprocesses requires supplementation as to ensure the best fermentative performance of microorganisms. However, in light of conflicting data in the literature, it is necessary to establish an inexpensive and applicable medium for the development of bioprocesses. This paper evaluates the fermentative performance of Scheffersomyces (Pichia) stipitis and Candida guilliermondii growth in sugarcane bagasse hemicellulosic hydrolysate supplemented with different nitrogen sources including rice bran extract, an important by-product of agroindustry and source of vitamins and amino acids. Experiments were carried out with hydrolysate supplemented with rice bran extract and (NH4)2SO4; peptone and yeast extract; (NH4)2SO4, peptone and yeast extract and non-supplemented hydrolysate as a control. S. stipitis produced only ethanol, while C. guilliermondii produced xylitol as the main product and ethanol as by-product. Maximum ethanol production by S. stipitis was observed when sugarcane bagasse hemicellulosic hydrolysate was supplemented with (NH4)2SO4, peptone and yeast extract. Differently, the maximum xylitol formation by C. guilliermondii was obtained by employing hydrolysate supplemented with (NH4)2SO4 and rice bran extract. Together, these findings indicate that: a) for both yeasts (NH4)2SO4 was required as an inorganic nitrogen source to supplement sugarcane bagasse hydrolysate; b) for S. stipitis, sugarcane hemicellulosic hydrolysate must be supplemented with peptone and yeast extract as organic nitrogen source; and: c) for C. guilliermondii, it must be supplemented with rice bran extract. The present study designed a fermentation medium employing hemicellulosic hydrolysate and provides a basis for studies about value-added products as ethanol and xylitol from lignocellulosic materials.

New cultive medium for bioconversion of C5 fraction from sugarcane bagasse using rice bran extract.

The use of hemicellulosic hydrolysates in bioprocesses requires supplementation as to ensure the best fermentative performance of microorganisms. However, in light of conflicting data in the literature, it is necessary to establish an inexpensive and applicable medium for the development of bioprocesses. This paper evaluates the fermentative performance of Scheffersomyces (Pichia) stipitis and Candida guilliermondii growth in sugarcane bagasse hemicellulosic hydrolysate supplemented with different nitrogen sources including rice bran extract, an important by-product of agroindustry and source of vitamins and amino acids. Experiments were carried out with hydrolysate supplemented with rice bran extract and (NH4)2SO4; peptone and yeast extract; (NH4)2SO4, peptone and yeast extract and non-supplemented hydrolysate as a control. S. stipitis produced only ethanol, while C. guilliermondii produced xylitol as the main product and ethanol as by-product. Maximum ethanol production by S. stipitis was observed when sugarcane bagasse hemicellulosic hydrolysate was supplemented with (NH4)2SO4, peptone and yeast extract. Differently, the maximum xylitol formation by C. guilliermondii was obtained by employing hydrolysate supplemented with (NH4)2SO4 and rice bran extract. Together, these findings indicate that: a) for both yeasts (NH4)2SO4 was required as an inorganic nitrogen source to supplement sugarcane bagasse hydrolysate; b) for S. stipitis, sugarcane hemicellulosic hydrolysate must be supplemented with peptone and yeast extract as organic nitrogen source; and: c) for C. guilliermondii, it must be supplemented with rice bran extract. The present study designed a fermentation medium employing hemicellulosic hydrolysate and provides a basis for studies about value-added products as ethanol and xylitol from lignocellulosic materials.

Cloning and functional characterization of LjPLT4, a plasma membrane xylitol H(+)- symporter from Lotus japonicus.

Polyols are compounds that play various physiological roles in plants. Here we present the identification of four cDNA clones of the model legume Lotus japonicus, encoding proteins of the monosaccharide transporter-like (MST) superfamily that share significant homology with previously characterized polyol transporters (PLTs). One of the transporters, named LjPLT4, was characterized functionally after expression in yeast. Transport assays revealed that LjPLT4 is a xylitol-specific H(+)-symporter (K (m), 0.34 mM). In contrast to the previously characterized homologues, LjPLT4 was unable to transport other polyols, including mannitol, sorbitol, myo-inositol and galactitol, or any of the monosaccharides tested. Interestingly, some monosaccharides, including fructose and xylose, inhibited xylitol uptake, although no significant uptake of these compounds was detected in the LjPLT4 transformed yeast cells, suggesting interactions with the xylitol binding site. Subcellular localization of LjPLT4-eYFP fusions expressed in Arabidopsis leaf epidermal cells indicated that LjPLT4 is localized in the plasma membrane. Real-time RT-PCR revealed that LjPLT4 is expressed in all major plant organs, with maximum transcript accumulation in leaves correlating with maximum xylitol levels there, as determined by GC-MS. Thus, LjPLT4 is the first plasma membrane xylitol-specific H(+)-symporter to be characterized in plants.

Arabidopsis thaliana POLYOL/MONOSACCHARIDE TRANSPORTERS 1 and 2: fructose and xylitol/H+ symporters in pollen and young xylem cells.

The genome of Arabidopsis thaliana contains six genes, AtPMT1 to AtPMT6 (Arabidopsis thaliana POLYOL/MONOSACCHARIDE TRANSPORTER 1-6), which form a distinct subfamily within the large family of more than 50 monosaccharide transporter-like (MST-like) genes. So far, only AtPMT5 [formerly named AtPLT5 (At3g18830)] has been characterized and was shown to be a plasma membrane-localized H(+)-symporter with broad substrate specificity. The characterization of AtPMT1 (At2g16120) and AtPMT2 (At2g16130), two other, almost identical, members of this transporter subfamily, are presented here. Expression of the AtPMT1 and AtPMT2 cDNAs in baker's yeast (Saccharomyces cerevisiae) revealed that these proteins catalyse the energy-dependent, high-capacity transport of fructose and xylitol, and the transport of several other compounds with lower rates. Expression of their cRNAs in Xenopus laevis oocytes showed that both proteins are voltage-dependent and catalyse the symport of their substrates with protons. Fusions of AtPMT1 or AtPMT2 with the green fluorescent protein (GFP) localized to Arabidopsis plasma membranes. Analyses of reporter genes performed with AtPMT1 or AtPMT2 promoter sequences showed expression in mature (AtPMT2) or germinating (AtPMT1) pollen grains, as well as in growing pollen tubes, hydathodes, and young xylem cells (both genes). The expression was confirmed with an anti-AtPMT1/AtPMT2 antiserum (alphaAtPMT1/2) raised against peptides conserved in AtPMT1 and AtPMT2. The physiological roles of the proteins are discussed and related to plant cell wall modifications.

Fermentation kinetics for xylitol production by a Pichia stipitis D: -xylulokinase mutant previously grown in spent sulfite liquor.

Spent sulfite pulping liquor (SSL) contains lignin, which is present as lignosulfonate, and hemicelluloses that are present as hydrolyzed carbohydrates. To reduce the biological oxygen demand of SSL associated with dissolved sugars, we studied the capacity of Pichia stipitis FPL-YS30 (xyl3Delta) to convert these sugars into useful products. FPL-YS30 produces a negligible amount of ethanol while converting xylose into xylitol. This work describes the xylose fermentation kinetics of yeast strain P.stipitis FPL-YS30. Yeast was grown in rich medium supplemented with different carbon sources: glucose, xylose, or ammonia-base SSL. The SSL and glucose-acclimatized cells showed similar maximum specific growth rates (0.146 h(-1)). The highest xylose consumption at the beginning of the fermentation process occurred using cells precultivated in xylose, which showed relatively high specific activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49). However, the maximum specific rates of xylose consumption (0.19 g(xylose)/g(cel) h) and xylitol production (0.059 g(xylitol)/g(cel) h) were obtained with cells acclimatized in glucose, in which the ratio between xylose reductase (EC 1.1.1.21) and xylitol dehydrogenase (EC 1.1.1.9) was kept at higher level (0.82). In this case, xylitol production (31.6 g/l) was 19 and 8% higher than in SSL and xylose-acclimatized cells, respectively. Maximum glycerol (6.26 g/l) and arabitol (0.206 g/l) production were obtained using SSL and xylose-acclimatized cells, respectively. The medium composition used for the yeast precultivation directly reflected their xylose fermentation performance. The SSL could be used as a carbon source for cell production. However, the inoculum condition to obtain a high cell concentration in SSL needs to be optimized.

Semi-continuous xylose-to-xylitol bioconversion by Ca-alginate entrapped yeast cells in a stirred tank reactor.

Candida guilliermondii FTI 20037 cells were entrapped in Ca-alginate beads and used for xylose-to-xylitol bioconversions during five successive batches in a stirred tank reactor. Supplemented sugarcane bagasse hemicellulosic hydrolysate was used as the fermentation medium. The average volume of the Ca-alginate beads was reduced by about 30% after the 600 h taken to perform the five bioconversion cycles, thus demonstrating physical instability under the conditions prevailing in the reactor vessel. In spite of this, almost steady bioconversion rates and yields were observed along the repeated batches. In average values, a production of 51.6 g l(-1), a productivity of 0.43 g l(-1 )h(-1) and a yield of 0.71 g g(-1) were attained in each batch, variation coefficients being smaller than 10%.

Saccharibacter floricola gen. nov., sp. nov., a novel osmophilic acetic acid bacterium isolated from pollen.

Three Gram-negative, aerobic, rod-shaped bacterial strains were isolated, from the pollen of Japanese flowers, as producers of xylitol; these strains were subjected to a polyphasic taxonomic study. Phylogenetic analyses of the 16S rRNA gene sequences demonstrated that these three isolates formed a new cluster within a group of acetic acid bacteria in the alpha-Proteobacteria. The characteristics of the three isolates were as follows: (i) their predominant quinone was Q-10; (ii) their cellular fatty acid profile contained major amounts of 2-hydroxy acids and an unsaturated straight-chain acid (C(18 : 1)omega7c); and (iii) their DNA G+C contents were in the range 51.9-52.3 mol%, which is around the lower limit of the reported range for the genera of acetic acid bacteria. The negligible or very weak productivity of acetic acid from ethanol and the osmophilic growth properties distinguished these strains from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the three isolates should be classified within a novel genus and species with the proposed name Saccharibacter floricola gen. nov., sp. nov. The type strain is strain S-877(T) (=AJ 13480(T)=JCM 12116(T)=DSM 15669(T)).

Effect of detoxification of dilute-acid corn fiber hydrolysate on xylitol production.

Four different detoxification methods were evaluated for the production of xylitol from corn fiber dilute-acid hydrolysate using Candida tropicalis. Although C. tropicalis could ferment the dilute partially neutralized hydrolysate to xylitol in low yields (0.1 g/g), it could not ferment the concentrated hydrolysate. Overliming, calcium hydroxide neutralization, neutralization combined with activated charcoal, and overliming combined with activated charcoal methods were used to improve the fermentation of the concentrated hydrolysates. The partial neutralization combined with activated charcoal treatment was the most effective method with respect to xylitol yield and productivity. The highest xylitol yield (0.4 g of xylitol/g of xylose) was obtained for the highest concentration of hydrolysate (three times the original) that had been treated with calcium hydroxide and activated charcoal. The corresponding productivity was 0.23 g/(L x h). Overliming caused reduction in xylitol yield.

Gluconeogenesis in the liver of arthritic rats.

The gluconeogenic response in the liver from rats with chronic arthritis to various substrates and the effects of glucagon were investigated. The experimental technique used was the isolated liver perfusion. Hepatic gluconeogenesis in arthritic rats was generally lower than in normal rats. The difference between normal and arthritic rats depended on the gluconeogenic substrate. In the absence of glucagon the following sequence of decreasing differences was found: alanine (-71.8 per cent) reverse similarglutamine (-71.7 per cent)>pyruvate (-60 per cent)>lactate+pyruvate (-44.9 per cent)>xylitol (n.s.=non-significant) reverse similarglycerol (n.s.). For most substrates glucagon increased hepatic gluconeogenesis in both normal and arthritic rats. The difference between normal and arthritic rats, however, tended to diminish, as revealed by the data of the following sequence: alanine (-48.9 per cent) reverse similarpyruvate (-47.6 per cent)>glutamine (-33.8 per cent)>glycerol (n.s.) reverse similarlactate+pyruvate (n.s.) reverse similarxylitol (n.s.). The causes for the reduced hepatic gluconeogenesis in arthritic rats are probably related to: (a) lower activities of key enzymes catalyzing most probably steps preceding phosphoenolpyruvate (e.g. phosphoenolpyruvate carboxykinase, pyruvate carboxylase, etc. ); (b) a reduced availability of reducing equivalents in the cytosol; (c) specific differences in the situations induced by hormones or by the individual substrates. Since glycaemia is almost normal in chronically arthritic rats, it seems that lower gluconeogenesis is actually adapted to the specific needs of these animals.

Dietary xylitol retards bone resorption in rats.

Dietary xylitol has previously been found to promote the content of calcium and minerals of the bone during rehabilitation following dietary calcium deficiency and during a normocalcemic diet in rats. This in vivo experiment was performed in order to study whether a short-term dietary xylitol supplementation affects bone resorption and calcium incorporation into bone during two different experiments utilizing either calcium-deficient or normocalcemic diets. Xylitol reduced bone resorption measured by the urinary excretion of 3H radioactivity both during calcium-deficient and normocalcemic diets. However xylitol reduced vitamin D levels only during calcium deficiency, indicating that the decreased bone dissolution was not associated with changes in 1,25(OH)2D3 concentration alone. Dietary xylitol did not alter 45Ca incorporation into bone, although this does not exclude the possibility that xylitol may have caused alterations in bone apposition. These results suggest that a short-term xylitol ingestion retards bone resorption in the rat.

Effects of xylitol- and/or glutamine-supplemented parenteral nutrition on septic rats.

1. The effects of parenteral nutrition with or without xylitol and/or glutamine supplementation were studied in septic rats after 4 days of treatment. 2. Septic rats treated with xylitol- and/or glutamine-supplemented parenteral nutrition survived sepsis significantly better than other parenteral nutrition-treated septic rats: the cumulative percentage of deaths over 4 days in septic rats treated with xylitol-glutamine-supplemented parenteral nutrition was 9.5% compared with 54.5% in septic rats given parenteral nutrition without xylitol and glutamine, and 52.4% in septic rats treated with parenteral nutrition supplemented with glucose. 3. Xylitol- and/or glutamine-supplemented parenteral nutrition resulted in improved nitrogen balance in septic rats: the cumulative nitrogen balance over the 4 days of treatment was positive in the rats given xylitol-supplemented parenteral nutrition and more positive when rats were treated with xylitol-glutamine-supplemented parenteral nutrition, as compared with other groups of septic rats. 4. The rate of loss of intracellular glutamine in skeletal muscle was markedly decreased (P less than 0.001) in response to xylitol- and/or glutamine-supplemented parenteral nutrition in septic rats. 5. Hepatic protein and RNA contents were increased in septic rats treated with xylitol- and/or glutamine-supplemented parenteral nutrition. Similarly, protein and RNA contents were markedly increased in muscles of septic rats treated with xylitol- and/or glutamine-supplemented parenteral nutrition. 6. The rates of incorporation of leucine/tyrosine into liver/muscle proteins in vitro were increased and the rate of muscular tyrosine release was decreased in response to xylitol- and/or glutamine-supplemented parenteral nutrition in septic rats. 7. It is concluded that the administration of xylitol- and/or glutamine-supplemented parenteral nutrition is beneficial to septic rats and possibly to septic patients.

Alterations in rat bone composition related to polyol supplementation of the diet.

The effect of dietary supplements of xylitol, sorbitol and glucose on bone composition was studied in rats. The supplementation, expressed as a % of the dry diet, was gradually increased up to 20% over 3 weeks and continued for 5 weeks. The control group was fed a stock diet only. Each group consisted of nine rats aged 12 weeks at the beginning of the experiment. Ca, Mg, P, CO3 and citrate were analysed from the femur and Ca and citrate also from the serum and urine. The results showed that xylitol supplementation significantly increased the concentrations of Ca and citrate in bone (P less than 0.001) and sorbitol that of Ca only, whereas glucose slightly reduced both CO3 and citrate. The citrate concentration was found to correlate significantly with Ca and P (P less than 0.001), and also with Mg (P less than 0.002). Both xylitol and sorbitol increased serum Ca and the urinary excretion of Ca and citrate. In conclusion, high xylitol or sorbitol supplementation affects Ca and citrate metabolism. The results suggest a connection between citrate and Ca in bone.

[Metabolism-oriented postoperative nutritional therapy--possibilities and limits in the use of glucose and xylitol]. / Stoffwechselorientierte postoperative Ernährungstherapie--Möglichkeiten und Grenzen der Anwendung von Glukose und Xylit.

Carbohydrates and polyols are essential constituents of intravenous nutrition. In order to better understand the problems associated with the supply of energy sources, the physiology of enteral nutrition will be covered and compared with intravenous nutrition. This review article will deal with the metabolic actions of glucose and xylitol and derive therapeutical consequences for their intravenous use during different illnesses.

Fructose, xylitol and glucose in total parenteral nutrition.

A comparison was made between isocaloric amounts of 24% glucose and 24% Triofusin (composed of 120 g fructose, 60 g glucose and 60 g xylitol per liter) during the course of a 6-day, 3-phase crossover study of 15 patients undergoing total parenteral nutrition. The patients received a total of 0.5 g carbohydrate per kg per day. Plasma glucose as significantly higher during glucose infusion (7-22 mmol/l, median: 9 mmol/l,) than during Triofusin infusion (5-16 mmol/l, median: 6 mmol/l). A moderate to severe glucosuria was detected in three patients during infusion of 24% glucose, and this declined considerably during the Triofusin period. The total renal carbohydrate loss during the glucose period was 0-143 g, median: 6 g per day, and during the Triofusin period was 6-68 g, median: 10 g per day. The nitrogen balance and carbamide production rate were the same in the two infusion regimes. Changes in biochemical liver parameters were observed in most of the patients, but these could not be attributed to parenteral nutrition. None of the patients developed symptoms of metabolic acidosis. There was a slightly but significantly higher urinary excretion of oxalate in the Triofusin period (0.1-1.1 mmol per day, median: 0.5 mmol per day) than in the glucose period (0.1-1.0 mmol per day, median: 0.4 mmol per day). Most of the patients exhibited a slightly increased urinary excretion of urate, irrespective of the infusion regimen. Serum urate remained normal. It was concluded that Triofusin infused in the described dosage is a suitable calorie source for parenteral nutrition, but that it does not present a distinct advantage over the use of pure glucose solution. In patients suffering from reduced glucose tolerance, however, Triofusin represents a more easily manageable calorie course.

[Metabolic behavior in total parenteral nutrition during the postoperative phase]. / Stoffwechselverhalten bei totaler parenteraler Ernährung in der postoperativen Phase

In patients who had undergone gastric operation, total postoperative parenteral nutrition was effected using a combination of two infusion solutions having complementary constituents. 80 g L-amino acids and about 2,500 kcal in the form of a glucose-levulose-xylitol mixture together with electrolytes and trace elements were infused daily. Metabolic parameters, serum levels and the concentrations of the most important administered substances excreted in the urine were determined every day at the same time. The 1:1:1 glucose-levulose-xylitol ratio of the caloric carrier proved to be a favourable combination with respect to metabolic behaviour and the necessary daily supply of calories. The basic electrolyte requirement of the patients was to a large extent met by the quantities contained in the solutions.