The physiological effects of dietary fiber—a review

Bioactive Exploration in Functional Foods: Unlocking Nature's Treasures

BACKGROUND

Functional foods offer an appealing way to improve health and prevent chronic diseases, and this subject has received much attention lately. They are effective in preventing chronic diseases like cancer, diabetes, heart disease, and obesity, according to research.

OBJECTIVE

This work presents an in-depth analysis of functional foods, covering key challenges from a scientific, legal, and commercial perspective.

METHODS

Multiple databases were searched to find studies on functional foods included in the systematic literature review. Various aspects of functional foods, from their classification, impact on human wellness, effectiveness in inhibiting chronic diseases, the regulatory environment, global market trends, and industry challenges, are all clarified in this thorough review.

RESULTS

This study aims to enhance understanding and establish a pathway for functional foods to be acknowledged as valid choices in the field of dietary supplements. It provides a thorough investigation of bioactive compounds present in functional foods, including but not limited to polyphenols, carotenoids, omega fatty acids, prebiotics, probiotics, and dietary fiber, along with an overview of their potential to mitigate chronic illnesses. We engage in an in-depth exploration of regulatory frameworks, shed light on groundbreaking research advancements, and meticulously examine strategies for commercialization and the variety of global challenges that accompany them. Establishing scientific consensus, navigating complex regulatory processes, dealing with skeptical consumers, and rising levels of competition are all problems that need to be solved in this field.

CONCLUSION

The field of functional foods can advance further, promoting better public health outcomes, by deeply comprehending and addressing these complex dimensions.

Unveiling the Evidence for the Use of Pulses in Managing Type 2 Diabetes Mellitus: A Scoping Review

Management of type 2 diabetes mellitus (T2DM) is a pressing global healthcare challenge. Innovative strategies that integrate superior medical and nutritional practices are essential for holistic care. As such, pulse consumption is encouraged for its potential benefit in reducing hypercholesterolaemia, dyslipidaemia, and triglyceride levels, as well as enhancing glycaemic control. This scoping review aims to assess the depth of evidence supporting the recommendation for pulse consumption in T2DM management and to identify gaps in the existing literature. We conducted a comprehensive search across the databases MEDLINE, Global Health, EMBASE, CINAHL, Web of Science, and the Cochrane Library (up to July 2023). We included population-based studies of any design, and excluded review-style articles. Articles published in languages other than English were also excluded. From the 2449 studies initially identified, 28 met our inclusion criteria. Acute postprandial trials demonstrated improved glucose responses and enhanced insulin responses to pulse-based intervention. Meanwhile, long-term trials reported meaningful improvements in T2DM indicators such as haemoglobin A1C (HbA1c), fasting glucose, fasting insulin, C-peptide, and markers of insulin resistance like homeostatic model assessment (HOMA). Integrating more pulses into the diets of diabetic individuals might offer an efficient and cost-effective strategy in the global initiative to combat T2DM.

Review article: the future of microbiome-based therapeutics

BACKGROUND

From consumption of fermented foods and probiotics to emerging applications of faecal microbiota transplantation, the health benefit of manipulating the human microbiota has been exploited for millennia. Despite this history, recent technological advances are unlocking the capacity for targeted microbial manipulation as a novel therapeutic.

AIM

This review summarises the current developments in microbiome-based medicines and provides insight into the next steps required for therapeutic development.

METHODS

Here we review current and emerging approaches and assess the capabilities and weaknesses of these technologies to provide safe and effective clinical interventions. Key literature was identified through Pubmed searches with the following key words, 'microbiome', 'microbiome biomarkers', 'probiotics', 'prebiotics', 'synbiotics', 'faecal microbiota transplant', 'live biotherapeutics', 'microbiome mimetics' and 'postbiotics'.

RESULTS

Improved understanding of the human microbiome and recent technological advances provide an opportunity to develop a new generation of therapies. These therapies will range from dietary interventions, prebiotic supplementations, single probiotic bacterial strains, human donor-derived faecal microbiota transplants, rationally selected combinations of bacterial strains as live biotherapeutics, and the beneficial products or effects produced by bacterial strains, termed microbiome mimetics.

CONCLUSIONS

Although methods to identify and refine these therapeutics are continually advancing, the rapid emergence of these new approaches necessitates accepted technological and ethical frameworks for measurement, testing, laboratory practices and clinical translation.

Physicochemical characteristics and sensory acceptability of crackers containing red ginseng marc

Red ginseng marc (RGM), a by-product from ginseng industry, still contains bioactive compounds such as ginsenosides and dietary fibers. The objective of this study was to investigate effects of baking conditions and formulations on physicochemical and sensory characteristics of crackers in which RGM was incorporated. The sum of ginsenoside Rb1, Rg1 and Rg3 (58.69 ± 2.93 mg/100 g, dry basis) and dietary fibers (7.52 ± 1.22 g/100 g) were the highest in the crackers baked at 120 °C for 60 min. The crackers with 5% replacement of wheat flour with RGM scored the highest in taste and overall acceptability. The baked crackers still contained relatively high amounts of ginsenoside Rb1 (7.62 ± 0.34 mg/100 g), Rg3(R) (7.51 ± 0.99 mg/100 g) and Rg3(S) (8.65 ± 0.77 mg/100 g) and dietary fiber (2.59 ± 0.17 g/100 g). The results suggest that low temperature-long time may be a suitable baking condition to retain bioactive ginsenosides in RGM and using proper amount of RGM in bakery products may improve not only nutritional quality but also sensory properties.

Alternative Bedding Materials for Poultry: Availability, Efficacy, and Major Constraints

The increasing demand of wood shavings (WS) and sawdust (SD) by other industries and growing concerns of potential chemical contaminants from wood products have amplified research interest in alternative bedding materials for commercial poultry. Several alternative materials-corn cob (CC), straws (ST) and hays (HA), sand (SA), shredded papers (SP), rice hulls (RH), peanut hulls (PH), and gypsum (CaSO4.2H2O2)-can replace conventional ones in poultry houses, depending on availability, cost, and ability to absorb and adsorb moisture and provide the birds enough room to exhibit their natural behaviors. Alternative materials hold a brighter future as bedding materials, but more studies about their physicochemical properties and litter management practices for optimum poultry welfare are recommended.

Effect of Intake of Food Hydrocolloids of Bacterial Origin on the Glycemic Response in Humans: Systematic Review and Narrative Synthesis

Diabetes mellitus is a chronic condition characterized by increased blood glucose levels from dysfunctional carbohydrate metabolism. Dietary intervention can help to prevent and manage the disease. Food hydrocolloids have been shown to have favorable properties in relation to glycaemic regulation. However, the use of food hydrocolloids of bacterial origin to modulate glucose responses is much less explored than other types of hydrocolloids. We, therefore, carried out the first review examining the impact of intake of food hydrocolloids of bacterial origin (as a direct supplement or incorporated into foods) on glycemic response in humans. Fourteen studies met the inclusion criteria. They used either xanthan gum, pullulan, or dextran as interventions. There was a wide variation in the amount of hydrocolloid supplementation provided and methods of preparation. Postprandial blood glucose responses were reduced in half of the studies, particularly at higher intake levels and longer chain hydrocolloids. When xanthan gum was added to the cooking process of muffins and rice, a significant reduction in postprandial blood glucose was observed. The use of these hydrocolloids is potentially effective though more research is needed in this area.

Dietary Fiber: Fractionation, Characterization and Potential Sources from Defatted Oilseeds

Dietary fiber (DF) has wide applications, especially in the food and pharmaceutical industries due to its health-promoting effects and potential techno-functional properties in developing functional food products. There is a growing interest in studies related to DF; nevertheless, there is less focus on the fractionation and characterization of DF. The characteristics of DF fractions explain their functionality in food products and provide clues to their physiological effects in food and pharmaceutical industrial applications. The review focuses on a brief introduction to DF and methods for its fractionation. It discusses the characterization of DF in terms of structural, physicochemical and rheological properties. The potential sources of DF from selected defatted oilseeds for future studies are highlighted.

Agaricus bisporus By-Products as a Source of Chitin-Glucan Complex Enriched Dietary Fibre with Potential Bioactivity

Mushroom production generates large amounts of by-products whose disposal creates environmental problems. The high abundance of biological active non-starch polysaccharides in mushroom cell walls makes these by-products attractive for dietary fiber-based ingredient (DFI) production. Traditional methods of dietary fiber preparation didn’t allow to obtain a DFI with suitable chemical and functional properties. In this work a simple and environmentally friendly method was developed and optimized for DFI production using a central composite design with treatment time, hydrogen peroxide and sodium hydroxide concentration as factors and chemical composition, chromatic and functional properties as dependent variables. The chemical composition of the DFI was strongly influenced by the process parameters and its functional and color properties were dependent on its fiber and protein content, respectively. The method developed is simple, uses food grade and low-cost reagents and procedures yielding a DFI with white color, no odor and a high concentration of dietary fiber (>60%) with an identical sugar composition to the original mushroom fiber. Due to the high water and oil retention capacity, this DFI may be used not only for dietary fiber enrichment and reduction of the food energy value but also as a functional ingredient with potential bioactivity.

Oral Administration of Succinoglycan Riclin Improves Diet-Induced Hypercholesterolemia in Mice

Epidemiological studies have demonstrated that hypercholesterolemia is associated with an elevated risk of atherosclerosis and cardiovascular diseases. In addition to the available cholesterol-lowering drugs, nutritionally balanced diets containing functional foods have attracted much interest as potential candidates to improve hypercholesterolemia. In the study, we demonstrated that dietary succinoglycan riclin effectively alleviated diet-induced hypercholesterolemia. Compared with the high-cholesterol-diet (HCD) group, the high-riclin group significantly decreased levels of the serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), and hepatic cholesterol (34, 40, and 51%, respectively), consequently improving hepatic steatosis and reducing proinflammatory cytokine expressions. ¹H nuclear magnetic resonance (NMR)-based lipidomics and metabolomics analyses revealed that the riclin group partially reversed metabolic profile changes induced by the HCD, approaching that of the normal diet (ND) group. Riclin has no direct effects on cholesterol metabolism-related gene expression among the three HCD model groups. Basically, riclin increased the solution viscosity and interfered in the process of bile acid-cholesterol emulsification, decreasing cholesterol digestion and promoting cholesterol and bile acid excretion in the feces. These results suggested potential therapeutic utility of succinoglycan riclin as a food additive for people suffering from hypercholesterolemia and related diseases.

Nutritional Composition, Antinutritional Factors, Antioxidant Activities, Functional Properties, and Sensory Evaluation of Cactus Pear (Opuntia ficus-indica) Seeds Grown in Tigray Region, Ethiopia

Cactus pear (Opuntia ficus-indica) seed is one of the main components of fruit crops. The seed is tightly packed together in a mucilaginous structure inside the endocarp of the fruit. The present study investigated the nutritional composition, antinutritional factors, and phytochemical and sensory attributes of cactus pear seeds collected from Hatset Kebele, Hawzen Woreda, Tigray region. The sample provides 392.84 kcal/100g energy in dry weigh basis. The dietary Ca, K, P, Fe, and Zn contents of the sample accounted 390.14mg, 446.46mg, 206.18mg, 4.37mg, and 2.01mg per 100 g, respectively. Despite the high phytate content (259.20mg/100g), the sample had appreciable amount of antioxidant capacity (43 to 95% of inhibition). The sample also had high value of water solubility index (5.6g/100g) and low value of bulk density (0.80g/ml). The sensory evaluation revealed that consumption of “Himbasha” (traditional bread) formulated with wheat flour was more preferable up to the ratio of 85:15% (wheat/seed).

Pre-pregnancy dietary carbohydrate quantity and quality, and risk of developing gestational diabetes: the Australian Longitudinal Study on Women's Health

Carbohydrate quantity and quality affect postprandial glucose response, glucose metabolism and risk of type 2 diabetes. The aim of this study was to examine the association of pre-pregnancy dietary carbohydrate quantity and quality with the risk of developing gestational diabetes mellitus (GDM). We used data from the Australian Longitudinal Study on Women's Health that included 3607 women aged 25-30 years without diabetes who were followed up between 2003 and 2015. We examined carbohydrate quantity (total carbohydrate intake and a low-carbohydrate diet (LCD) score) and carbohydrate subtypes indicating quality (fibre, total sugar intake, glycaemic index, glycaemic load and intake of carbohydrate-rich food groups). Relative risks (RR) for development of GDM were estimated using multivariable regression models with generalised estimating equations. During 12 years of follow-up, 285 cases of GDM were documented in 6263 pregnancies (4·6 %). The LCD score, reflecting relatively high fat and protein intake and low carbohydrate intake, was positively associated with GDM risk (RR 1·54; 95 % CI 1·10, 2·15), highest quartile v. lowest quartile). Women in the quartile with highest fibre intake had a 33 % lower risk of GDM (RR 0·67; 95 % CI 0·45, 0·96)). Higher intakes of fruit (0·95 per 50 g/d; 95 % CI 0·90, 0·99) and fruit juice (0·89 per 100 g/d; 95 % CI 0·80, 1·00)) were inversely associated with GDM, whereas cereal intake was associated with a higher risk of GDM (RR 1·05 per 20 g/d; 95 % CI 1·01, 1·07)). Thus, a relatively low carbohydrate and high fat and protein intake may increase the risk of GDM, whereas higher fibre intake could decrease the risk of GDM. It is especially important to take the source of carbohydrates into account.

Modification of carrot (Daucus carota Linn. var. Sativa Hoffm.) pomace insoluble dietary fiber with complex enzyme method, ultrafine comminution, and high hydrostatic pressure

Insoluble dietary fiber (DF) extracted from carrot pomace was modified by complex enzyme method, ultrafine comminution and high hydrostatic pressure and their structural, physicochemical, and functional properties were evaluated. Results showed that complex enzyme method increased the content of soluble DF to 15.07%, and the cholesterol adsorption capacity peaked; ultrafine comminution greatly improved the total antioxidant activities, DPPH radical scavenging capacity and antioxidant abilities in linoleic acid system of DF; high hydrostatic pressure led to a significant increase in capacities of water retention (7.14 g/g, 600 MPa), water swelling (10.02 mL/g, 500 MPa), oil retention (2.35 g/g, 500 MPa), cation exchange (2.29 mmol/g, 600 MPa), and glucose adsorption (2.634 mmol/g, 400 MPa). Furthermore, SEM showed that surface structures of all modified DF were loose. Overall, three kinds of modification methods have shown their respective advantages. Modified DF from carrot pomace can be applied as a functional ingredient in diverse food products.

Composition and Physicochemical Characterization of Fiber-Rich Food Processing Byproducts

A wide range of fiber-rich food processing byproducts from various sources have been proposed as value-added ingredients for producing healthier food products. Characterizing their composition and physicochemical properties is crucial to understand their potential uses. Eight fiber-rich byproducts from different sources were fractionated into 2 different particle-size ranges. Different (P ≤ 0.05) proximate composition and physicochemical properties (pasting properties, water-binding capacity, and oil-binding capacity) were exhibited by them. These properties enabled hierarchical cluster analysis and principal component analysis to group the byproducts into 3 different clusters by functionality and from this, assigned ingredients in each cluster to a potential end-uses. Some end use examples include, as a source of fat, protein, sugar, and insoluble fiber; and for uses as a thickening agent, water-binder, emulsion-enhancer, and fat-binder.

PRACTICAL APPLICATION

The data presented in this study can be used by food manufacturers and product developers as the basis for choosing fiber-rich byproducts for specific applications and assist them in developing specific formulation and processing strategies. This characterization will reduce the time for development of fiber-rich foods, increasing industrial uses of byproducts, and decreasing food waste.

Inhibition of key digestive enzymes related to hyperlipidemia and protection of liver-kidney functions by Cystoseira crinita sulphated polysaccharide in high-fat diet-fed rats

The objective of this current study was to investigate the possible hyperlipidemic and antioxidative effects of Cystoseira crinita sulfated polysaccharide (CCSP) in rats fed with a high-fat diet, exhibited an inhibitory activity on pancreatic lipase in vitro. In vivo administration of this extract to HFD-rats lowered body weight and potentially inhibited key enzymes of lipid metabolism and absorption as lipase activity in both plasma and small intestine, which led to a notable decrease of blood LDL- cholesterol (LDL-Ch) and triglycerides (TG) levels, and an increase in HDL-cholesterol (HDL-Ch) levels in HFD-rats. CCSP was also observed to protect the liver-kidney functions efficiently, by decreasing of aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH) and Creatine phosphokinase (CPK) activities and creatinine, albumin, T-bilirubin, uric acid, and urea rates in plasma. The histological analysis of liver and kidney tissues further established the positive effect of CCSP.

Preparation and characterization of quercetin/dietary fiber nanoformulations

Quercetin is well known for its beneficial health effects on the human body. However, the slow dissolution rate leading to poor bioavailability constitutes a barrier to being further developed for nutritional products. In this work, quercetin was co-precipitated with dietary fibers into a fast-dissolving nanoformulation via antisolvent precipitation, followed by spray drying. With the help of cellulose fiber, resistant starch or resistant maltodextrin, a high dissolution rate and good storage stability was achieved for quercetin nanoformulations. In addition, nanoformulations exhibited higher level of antioxidant activities in contrast to raw quercetin. The developed quercetin/dietary fiber nanoformulations could be used as supplements or functional ingredients for food development.

Probiotics, Soluble Fiber, and L-Glutamine (GLN) Reduce Nelfinavir (NFV)or Lopinavir/Ritonavir (LPV/r)-related Diarrhea

Purpose: Highly active antiretroviral therapy (HAART) can be associated with diarrhea and other gastrointestinal (GI) side effects. Reducing these side effects may improve treatment durability and quality of life (QOL). This study assessed the impact of nutritional co-therapies known to reduce diarrhea in HIV-positive men treated with nelfinavir (NFV)- or lopinavir/ritonavir (LPV/r)-containing regimens. Methods: Thirty-five HIV-positive men treated with NFV (n = 27) or LPV/r (n = 8) with diarrhea (± two liquid stools/day [d]) participated in a 12-week prospective study. Twenty-eight subjects were randomly assigned supplements (S), seven received standard of care (C). Group S received probiotics (1.2g/d) and soluble fiber (11g/d). If diarrhea persisted at week 4, 30g/d L-Glutamine (GLN) was added. Diarrhea incidence, as well as supplement and antidiarrheal use, was assessed monthly. Results: Weight, CD4 count, and HIV RNA were unchanged in both groups. Diarrhea completely resolved in 10 of 28 (36 percent) S subjects. The mean (± SD) number of stools/d declined [3.40 ± 1.25 to 2.54 ± 1.34 (p < 0.01)]. Diarrhea (loose, watery stools/d) lessened in S from 2.84 ± 1.42 to 0.74 ± 1.03 (p < 0.0001). Fifteen S subjects did not obtain full relief with probiotics and fiber, but stools/d decreased from 4.08 ± 1.35 to 3.06 ± 1.68 (p < 0.05) after starting GLN. In C, stools/d, 4.14 ± 4.86 to 3.44 ± 1.68(p = 0.678) and incidence of diarrhea/d, 3.00 ± 4.82 to 1.36 ± 1.29 (p= 0.361) was unchanged. In S, loperamide use decreased from 1.69 ± 2.34 to 0.31 ± 0.69 mg/d (p < 0.01); 18 versus eight subjects used loperamide at 0 and 12 weeks, respectively. Conclusion: Probiotics, soluble fiber, and GLN significantly reduced diarrhea for subjects receiving NFV or LPV/r. Nutritional co-therapies show clinical benefit in HIV-positive men with diarrhea.

Hydrocolloids Decrease the Digestibility of Corn Starch, Soy Protein, and Skim Milk and the Antioxidant Capacity of Grape Juice

Hydrocolloids have many applications in foods including their use in dysphagia diets. We aimed to evaluate whether hydrocolloids in foods affect the digestibility of starch and protein, and their effects on antioxidant capacity. The thickening hydrocolloids: locust bean gum and carboxymethyl cellulose, and the gel-forming agents: agar agar, konjac-glucomannan, and Hot & Soft Plus were blended with corn starch and soy protein, skim milk, or grape juice and were examined for their in vitro-digestability by comparing the reducing sugar and trichloroacetic acid (TCA)-soluble peptide, for antioxidant capacity by total polyphenol contents and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. The hydrocolloids resulted in a decrease in starch digestibility with the gel-forming agents. Hydrocolloids diminished TCA-soluble peptides in skim milk compared to soy protein with the exception of locust bean gum and decreased free radical scavenging capacities and total phenolic contents in grape juice. Our findings may provide evidence for the use of hydro-colloids for people at risk of nutritional deficiencies such as dysphagia patients.

Physicochemical and Functional Properties of Insoluble Dietary Fiber Isolated from Bambara Groundnut (Vigna subterranea [L.] Verdc.)

Bambara groundnut (BGN) is a widely cultivated legume with a rich nutritional profile, yet despite its many benefits it still remains underutilized. To highlight its potential value, 4 BGN varieties-brown, red, black eye, and brown eye were subjected to sequential enzymatic treatments followed by centrifugation to obtain the insoluble dietary fiber (IDF) fraction. The IDFs were vacuum-dried and evaluated for color, hydration properties, fat absorption, polyphenolic compounds, neutral sugars, and uronic acids. An optimized white bread formulation was also determined using brown BGN-IDF in an optimal (IV) mixture design. Three mixture components constrained at lower and upper limits (water: 57% to 60%, yeast: 2.3% to 5.3%, and BGN-IDF: 7% to 10%) were evaluated for their effects on responses of specific loaf volume, gumminess, chewiness, and resilience of the loaves. All BGN-IDFs differed significantly (P ≤ 0.05) across all color parameters. Polyphenols were significantly (P ≤ 0.05) highest in red and brown BGN-IDFs. Arabinose/galactose (31.04% to 37.12%), xylose (16.53% to 27.30%), and mannose (14.48% to 22.24%) were the major sugars identified. Swelling capacity was significantly (P ≤ 0.05) highest for brown eye BGN-IDF (7.72 ± 0.49 mL/g). Water retention capacity ranged from 1.63 to 2.01 g water/g dry weight. Fat absorption for red BGN-IDF differed significantly (P ≤ 0.05). Furthermore, the best optimal white bread formulation enriched with brown BGN-IDF was established with numerical optimization at 59.5% water, 4.3% yeast, and 8.5% BGN-IDF. Overall positive physicochemical and functional properties were observed for BGN-IDFs, and it was shown that an optimal white bread enriched with BGN-IDF could be produced.

Functional and physiological properties of total, soluble, and insoluble dietary fibres derived from defatted rice bran

Enzymatic- gravimetric method was used to obtain three fractions of dietary from defatted rice bran. The functional and physiological properties such as viscosity, cation exchange capacity (CEC), and glucose dialysis retardation index (GDRI), cholesterol and bile salt adsorption capacity of the resultant fractions were evaluated. Insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) when compared showed that SDF exhibited significantly (p < 0.05) higher viscosity (2.35 mPa.s), greater GDRI value (17.65 %) at 60 min and significantly lowered concentration of cholesterol at pH 7 (29.90 %, p < 0.05). However IDF showed the highest CEC and its adsorption capacity of bile salt was higher than SDF (18.20 % vs. 13.76 %; p < 0.05), while CEC and cholesterol absorption capacity of TDF were similar to SDF. These properties indicate that rice bran soluble, insoluble and total fibres are functional ingredients which can be added to various food products and dietetic, low-calorie high-fiber foods to enhance their nutraceutical properties and health benefits.

Evaluation of physicochemical properties, proximate and nutritional composition of Gracilaria edulis collected from Palk Bay

Gracilaria edulis, a red alga present in southeast coast of India was evaluated for its nutritional composition. FT-IR analysis of soluble polysaccharides revealed the presence of galactans, 3,6-anhydro-α-L-galactopyranose, sulphated galactose and the gelling agent agar, with the sulphate content estimated as 51.01 μg/mg of polysaccharide. Results of physicochemical properties and nutritional profile reveal the presence of dietary fibre (8.9 ± 0.62% DW), carbohydrate (101.61 ± 1.8 mg/g DW), crude protein (6.68 ± 0.94 mg/g DW) and lipid content (8.3 ± 1.03 mg/g DW). G. edulis contains biologically important fatty acids like palmitic acid (2.06%), linolenic acid (2.56%), and oleic acid (1.98%). The other nutritional components present in high amounts are proline, chlorophyll A and B, all the essential amino acids and vitamin A, E and C. These findings suggest that G. edulis has potent nutritional value which might be used as a source of nutrients for human and animals.

Functional properties and dietary fiber characterization of mango processing by-products (Mangifera indica L., cv Ataulfo and Tommy Atkins)

Several reports have focused on utilization of post-harvest residues of crops, while neglecting those residues produced by mango processing. These residues represent a waste of nutrients and a source of environmental contaminants. Such by-products could be valuable sources of dietary fiber (DF), antioxidant compounds, and single carbohydrates. The aim of this study was to evaluate some functional properties (FP), and the content of DF and polyphenols (PP) of the peel and coarse material obtained from residues during the industrial processing of Ataulfo and Tommy Atkins mangoes. The total dietary fiber (TDF) content was about 225 mg/g and 387 mg/g (dry weight) for the coarse material and the peel, respectively, from which soluble dietary fiber represented 23 and 42%, respectively. The main neutral sugar identified was rhamnose, especially in peels; the klason lignin (KL) content was 92 mg/g, which highlights the Ataulfo peel (Ataulfo-P) and the Tommy Atkins peel (Tommy Atkins-P). The extractable PP content in Ataulfo-P was higher than in Tommy-Atkins-P, and interesting data for non-extractable PP were obtained in the residues. FP as swelling, water holding, oil holding, and glucose absorption in the residues was studied, obtaining better functional properties when compared to cellulose fiber. The results show that mango industrial by-products, mainly from the Ataulfo-P variety, could be used as ingredients in food products because of their functional properties as well as their DF and PP content.

In vitro hypoglycemic and cholesterol lowering effects of dietary fiber prepared from cocoa (Theobroma cacao L.) shells

Three dietary fiber (DF) powders; soluble dietary fiber (SDF), insoluble dietary fiber (IDF) and total dietary fiber (TDF) were prepared from cocoa bean shells (CBS) by enzymatic treatment. These DFs were evaluated for their effects on glucose adsorption, glucose diffusion, starch hydrolysis, cholesterol binding, sodium cholate binding and oil binding capacities using in vitro model systems by simulating gastric intestinal conditions. The results showed that SDF generally exhibited significantly (p < 0.05) higher glucose adsorption capacity (GAC), α-amylase inhibition activity, cholesterol and sodium cholate binding capacity, but less significant (>0.05) glucose dialysis retardation index (GDRI) and oil binding capacity, when compared with IDF and TDF which both showed similar effects. Moreover, it was discovered that the three CBS dietary fiber powders contained intrinsic antioxidants (phenolic compounds). The study suggested that CBS could be an alternative cheap source of DF with additional benefits. Thus, CBS fibers could be incorporated as low calorie bulk ingredients in high-fiber diet to reduce calorie and cholesterol levels and control blood glucose level.

Dietary fibre in foods: a review

Dietary fibre is that part of plant material in the diet which is resistant to enzymatic digestion which includes cellulose, noncellulosic polysaccharides such as hemicellulose, pectic substances, gums, mucilages and a non-carbohydrate component lignin. The diets rich in fibre such as cereals, nuts, fruits and vegetables have a positive effect on health since their consumption has been related to decreased incidence of several diseases. Dietary fibre can be used in various functional foods like bakery, drinks, beverages and meat products. Influence of different processing treatments (like extrusion-cooking, canning, grinding, boiling, frying) alters the physico- chemical properties of dietary fibre and improves their functionality. Dietary fibre can be determined by different methods, mainly by: enzymic gravimetric and enzymic-chemical methods. This paper presents the recent developments in the extraction, applications and functions of dietary fibre in different food products.

Physicochemical, nutritional, and functional characterization of fruits xoconostle (Opuntia matudae) pears from Central-México Region

Xoconostle cv. Cuaresmeño (Opuntia matudae) has attracted domestic and international industry attention; however, variations of composition from xoconostle structures have not been evaluated. Industries discard the pulp (endocarp) and peel (pericarp) as wastes and utilize the skin (mesocarp), which is the edible portion. The physicochemical, nutritional, and functional characterization of structures from xoconostle pear from 3 major sites of production in Mexico were assessed. Skin yield ranged from 58% to 64% and was higher to that of peel (22% to 24%) and pulp (12% to 18%) yields. pH, degrees Brix, and acidity were similar among xoconostle structures. Total fiber showed by peel (18.23% to 20.37%) was 2-fold higher than that of skin. Protein and ether extract were higher in xoconostle pulp compared to that showed by peel and skin. Iron content of xoconostle peel (6 to 9.6 mg/100 g, DWB) was higher to that of skin and pulp and prickly pear pulp. Soluble phenols of peel (840 to 863 mg GAE/100 g, DWB) were almost similar to that of skin (919 to 986 mg GAE/100 g, dry weigh basis); meanwhile, ascorbic acid concentration of skin was 2-fold higher compared to that of peel. The phenolic fraction of xoconostle structures consisted of gallic, vanillic, and 4-hydroxybenzoic acids; catechin, epicatechin, and vanillin were also identified by high-performance liquid chromatography-didoe array detection (HPLC-DAD). Xoconostle peel showed higher antioxidant activity (TEAC) compared to that of skin (2-fold) and pulp (6-fold) of commonly consumed fruits and vegetables. The potential of xoconostle peel and pulp for the production of feed or food is promissory. Practical Application: Outstanding nutritional and functional properties of xoconostle cv. Cuaresmeño fruits are demonstrated. Increased consumption could contribute positively to improve the diet of rural and urban consumers. The high fiber, mineral, and antioxidant components of xoconostle peel and pulp suggest that these fruit structures, which are currently discarded as waste, have promissory use as feed or food by industry.

Cell wall fractions isolated from outer layers of rye grain by sequential treatment with alpha-amylase and proteinase: structural investigation of polymers in two ryes with contrasting breadmaking quality

Recent studies have indicated that some structural features of arabinoxylans, the major cell wall polysaccharides, might be potential quality markers in the selection of rye breeding materials. To specify the most appropriate characteristics, the differences in the structure of cell wall components were studied in two ryes with high and low breadmaking qualities. Two cell wall fractions were isolated from the outer layers of the grain (pooled shorts and bran fractions) by a consecutive water extraction with alpha-amylase (WE-A) and proteinase K (WE-P). Polysaccharides predominated in the WE-A fraction (approximately 64%, mainly arabinoxylans). By contrast, the WE-P fraction contained mostly protein (approximately 63%), and its level of polysaccharides was relatively low (approximately 18%). The 1H NMR and sugar analysis of the ammonium sulfate precipitated subfractions revealed that the WE-A was built of four arabinoxylan populations with marked structural differences (arabinose-to-xylose ratios, Ara/Xyl, of approximately 0.3, 0.5, 0.8, and 1.2). Instead, the arabinoxylans present in the WE-P were generally enriched in disubstituted xylopyranosyl residues. The ratio of phenolic components to arabinose residues in the WE-P fraction (indicated by 1H NMR) and the proportion of polymers with the highest molecular weights in the WE-A fraction (revealed by HPSEC) distinguished well two ryes with diverse breadmaking qualities. Much less obvious differences between both ryes were observed in the ratio of amide I to amide II band intensities of FTIR spectra for the WE-P and in the level of phenolic acids and ferulic acid dehydrodimers for both cell wall preparations.

Cactus stems (Opuntia spp.): A review on their chemistry, technology, and uses

Although traditionally used as a valuable health supporting nutrient, the vegetative parts of Opuntia spp. plants are scarcely used in modern nutrition and medicine. While all kinds of different Opuntia spp. have been studied, a systematic approach regarding the inter-relationships between the composition and the pre- and postharvest conditions is still missing. Therefore, the present review compiles and discusses literature on the chemical composition of cactus stems, the knowledge on uses in food, medicine, and cosmetics. It is concluded that much research is needed to get an insight into the multitude of bioactivities reported in the traditional literature but also to take advantage of the respective constituents for food and pharmaceutical applications.

Chronological changes and inter-regional differences in dietary fiber intakes among middle-aged Japanese women

Dietary fiber intake was estimated by the total food duplicate method, using a computerized system for fiber calculation recently developed by this study group. Collection of food duplicates were conducted twice, once in 1979-83 and then in 1990-95, in 20 sites across Japan. Altogether 294 and 384 nonsmoking, nonhabitually drinking adult women offered the samples, in the first and second survey, respectively. The average intake of total fiber was 20.7 g/day in the first study, and it was 18.7 g/day in the second survey with a significant reduction. Soluble fiber accounted for 18 to 19%, and the reduction was more marked in soluble fiber than in insoluble fiber. There was an inter-regional difference in fiber intake which was more evident in the first survey than in the second; farmers in Okinawa took less soluble, insoluble and total fiber than in Hokkaido and Honshu farmers and also urban residents. Throughout the four groups, the leading fiber sources were vegetables, followed by cereals, fruits and pulse in the decreasing order. Intakes of these foods diminished during the two survey period, and the reduction of fiber from cereals was most evident in Honshu and Okinawa farmers. International comparison showed that the current level of fiber intake in Japan is essentially similar to the levels in Europe and USA, despite the long-term trend of reduction.

Effect of dose and modification of viscous properties of oat gum on plasma glucose and insulin following an oral glucose load

An extract from oats known as oat gum (OG) is composed mainly of the polysaccharide (1-->3) (1-->4)-beta-D-glucan, which is highly viscous in aqueous solution. Viscous polysaccharides are known to attenuate postprandial plasma glucose and insulin responses. The purposes of this study were to determine the dose-response to OG and establish quantitatively the effect of viscosity on plasma glucose and insulin levels of healthy humans consuming 50 g glucose. Increasing the dose of OG successively reduced the plasma glucose and insulin responses relative to a control without gum. Reduction of the viscosity of OG by acid hydrolysis reduced or eliminated the capacity to decrease postprandial glucose and insulin levels. The ability of OG to modify glycaemic response was unchanged following agglomeration in the presence of maltodextrin. Agglomerated gum dispersed smoothly in a drink without formation of lumps, and development of maximum viscosity was delayed. These properties improve palatability. There was a highly significant linear relationship between log[viscosity] of the mixtures consumed and the glucose and insulin responses. The relationship shows that 79-96% of the changes in plasma glucose and insulin are attributable to viscosity, and that changes occur at relatively low doses and viscosities.

Dietary fiber, inulin, and oligofructose: a review comparing their physiological effects

Dietary fiber is a general term. It covers a wide variety of substances that belong to the family of carbohydrates that resist hydrolysis by human alimentary enzymes but are fermented by colonic microflora. The main physiological effects of dietary fiber are primarily on gastric emptying and small intestinal transit time, resulting in an improved glucose tolerance and a decreased digestion of starch: second, on colonic transit time and large bowel functions due to fermentation by ceco-colonic microbial flora or bulking action. The so-called soluble dietary fibers are fermented to a large extent by a wide variety of anaerobic bacteria that result in an increase in bacterial biomass, an increase in fecal mass, a change in intracolonic pH, and production of short chain fatty acids and various gases as metabolic end products. The insoluble fibers are only marginally fermented: they serve almost exclusively as bulking agents that result in shorter transit time and increased fecal mass. The short chain fatty acids resulting from the colonic fermentation of dietary fiber are largely absorbed via the portal blood and reach both the liver and the peripheral tissues. They induce changes in glucose and fat metabolism leading to post-prandial hypoglycemia and long-term hypolipidemia. Inulin and oligofructose are fructans with a degree of polymerization of 2 to 60 and 2 to 20, respectively. Due to the structural conformation of their osidic bridge (beta 2-1), they both resist the hydrolysis by human alimentary enzymes. Moreover, when reaching the colon, both inulin and oligofructose are almost quantitatively fermented almost exclusively by colonic bifidobacteria and bacteroides. Such an extensive fermentation causes an increase in fecal bacterial biomass, a decrease in ceco-colonic pH, and produces a large amount of fermentation products among which the short chain fatty acids that exert systemic effects on lipid metabolism. Thus, both inulin and oligofructose have most of the characteristics of a dietary fiber and the proposal is made to classify them as such. Moreover, they are bifidogenic factors, because, due to still unknown reasons, they are primarily fermented by bifidobacteria. It is concluded from this review that "nondigestible fructo-oligosaccharides," even though they are not included in the carbohydrate fraction that is quantified as dietary fiber by classic analytical methods, have most of the physiological effects of a dietary fiber.(ABSTRACT TRUNCATED AT 400 WORDS)