Effect of fat type in baked bread on amylose-lipid complex formation and glycaemic response

Simple Method for Preparing Starch Inclusion Complexes with Enhanced Amylolysis Resistance and Antioxidant Properties

Slow-digesting starch with bioactive functionality has been attracting much interest with the increasing incidence of type-2 diabetes and other diet-related illnesses. The present study demonstrates a simple method for preparing a starch inclusion complex with reduced enzymic digestion and enhanced antioxidant activities using debranched pea starch (PS) and 10-gingerol (10G). Enzymically debranched starch complexed more 10G and formed more structurally ordered starch-10G complexes compared to PS that had not been debranched. Debranching for 6 h resulted in starch with better complexing ability for 10G than starches debranched for longer times. The debranched starch-10G complexes had higher antioxidant activities and a much slower in vitro enzymic digestion profile (rate and hydrolysis extent) than the 10G complex prepared with starch that was not debranched. Our study demonstrates that debranched pea starch-10G complexes with slow-digesting and antioxidant properties are likely to be of interest for developing ingredients for healthier food choices.

Potato Resistant Starch Type 1 Promotes Obesity Linked with Modified Gut Microbiota in High-Fat Diet-Fed Mice

Obesity has become a major disease that endangers human health. Studies have shown that dietary interventions can reduce the prevalence of obesity and diabetes. Resistant starch (RS) exerts anti-obesity effects, alleviates metabolic syndrome, and maintains intestinal health. However, different RS types have different physical and chemical properties. Current research on RS has focused mainly on RS types 2, 3, and 4, with few studies on RS1. Therefore, this study aimed to investigate the effect of RS1 on obesity and gut microbiota structure in mice. In this study, we investigated the effect of potato RS type 1 (PRS1) on obesity and inflammation. Mouse weights, as well as their food intake, blood glucose, and lipid indexes, were assessed, and inflammatory factors were measured in the blood and tissues of the mice. We also analyzed the expression levels of related genes using PCR, with 16S rRNA sequencing used to study intestinal microbiota changes in the mice. Finally, the level of short-chain fatty acids was determined. The results indicated that PRS1 promoted host obesity and weight gain and increased blood glucose and inflammatory cytokine levels by altering the gut microbiota structure.

Relations between in vitro starch digestibility of commercial baked products and their macronutrients

BACKGROUND

Baked products such as biscuits and breads are the staple foods for a large population, with the starch digestion rate having a crucial effect on human health. Currently, there is a lack of information on general starch digestibility in commercial baked products and its correlation with macronutrient content.

RESULTS

The present study investigated the starch digestibility of 35 commercial baked products, ranging from low to high moisture contents. Biscuits generally had a slower starch digestion rate than mini-breads, whereas breads including whole wheat bread had the fastest digestion rate. Additionally, starch digestibility was negatively correlated with the calorie (R²  = 0.71) and fat content (R²  = 0.56) in per serving size, possibly because of the formation of amylose-lipid complex.

CONCLUSION

The present study provides a database for the in vitro starch digestibility of a large number of food items, which gives general indications on the performance of starch components of commercial products in the human gastrointestinal tract. © 2022 Society of Chemical Industry.

Enhancing health benefits of bakery products using phytochemicals

There has been a growing interest in functional bakery products with enhanced health benefits, especially the prevention of some chronic diseases such as type 2 diabetes, cardiovascular diseases and neurodegenerative disorders. Fortification of wheat flour with phytochemicals, plant components with various bio-activities, is one of the promising approaches to improving public health with the ubiquitous consumption of baked goods. This chapter reviews the current knowledge of several representative phytochemicals, mainly plant polyphenols, including catechins, anthocyanins, fucoidan and quercetin extracted from various plant resources, and their application in bakery products, regarding their stability, impact on product quality and potential health benefits.

Seaweeds as Ingredients to Lower Glycemic Potency of Cereal Foods Synergistically-A Perspective

Seaweeds are traditional food ingredients mainly in seaside regions. Modern food science and nutrition researchers have identified seaweed as a source of functional nutrients, such as dietary soluble and insoluble fibers, proteins, omega-3 fatty acids, prebiotic polysaccharides, polyphenols, and carotenoids. Owing to the rich nutrients, seaweeds and seaweed extract can be used as functional ingredients by modifying the nutrients composition to reduce the proportion of available carbohydrates, delaying the gastric emptying time and the absorption rate of glucose by increasing the digesta viscosity, and attenuating the digesting rate by blocking the activity of digestive enzymes. This review presents the concept of using seaweed as unconventional ingredients that can function synergistically to reduce the glycemic potency of cereal products.

Effects of consumption of coconut oil or coconut on glycemic control and insulin sensitivity: A systematic review and meta-analysis of interventional trials

BACKGROUND AND AIMS

The often purported claim that coconut fat is beneficial for cardiovascular health and was disputed in several recent meta-analyses. However, the evidence on the effects of coconut fat intake on glycemic control remains equivocal. We conducted a systematic review and meta-analysis in accordance with the PRISMA guidelines to determine the effects of dietary coconut fats on markers of acute and long-term glycemic control.

METHODS AND RESULTS

PubMed, Scopus, ProQuest, and Web-of-Science databases were searched and the records were screened by three independent reviewers to identify interventional studies examining acute and long-term (i.e., >10 days) effects of coconut fat on glycemic control. DerSimonian-Laird random-effects meta-analyses were performed using the meta-package in R (4.0.2). Seven interventional studies on acute effects and 11 interventional studies on long-term effects of coconut fat were included. Meals with coconut fat acutely increased the incremental area under the curve (AUC) of glucose (p = 0.046) and decreased the incremental AUC of insulin (p = 0.037) vs. control meals. Long-term coconut fat intake increased HOMA-IR (p = 0.049), but did not significantly affect fasting glucose, insulin, or HOMA-β vs. control meals.

CONCLUSIONS

Coconut fat in meals seems to be associated with a diminished postprandial insulin response, resulting in a subtle increase in the postprandial glycemic response. Long-term intake of coconut fat seems to increase insulin resistance, yet does not seem to be beneficial for long-term glycemic control. Thus, our results disprove the popular claim that coconut fat improves glycemic control.

REGISTRATION

PROSPERO registry (CRD42020183450).

Preparation and characterization of corn flours with variable starch digestion

Several grains such as wheat, rice, corn, oat, barley and rye are cultivated throughout the world. They are converted to variety of food products using a multitude of processing technologies to quench the growing organoleptic demands and consumers' preferences. Among them, corn, ranking third in wide consumption, is cost-effective and has long-term storability. Herein, ready-to-eat corn flours with variable starch digestion have been developed by processing at high temperature with shear using a twin screw continuous processor. The influence of processing temperature (121, 145 and 160°C) and moisture (25, 30 and 35%) has been studied. Results suggest both processing temperature and moisture modulate the rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) amounts of the flours. The presence or absence of oil in the flour further controls the starch digestion. The outcome is deemed to be helpful to design and develop healthy and palatable functional food products in addition to furthering the current market share for corn and other grains.

Resistant Starch Production and Glucose Release from Pre-Prepared Chilled Food: The SPUD Project

With an increasing prevalence of diabetes worldwide, effective dietary strategies for blood glucose control are crucial. As carbohydrates make up approximately 50% of the diet, it is neither practical nor advisable to avoid them altogether. Most of the carbohydrate in the diet is derived from starch, found in potatoes, pasta, rice and bread. These foods are often processed in some way before consumption, yet little is known about the effects processing, such as chilling and reheating, has on the glycaemic response, particularly when the food is consumed in the context of a mixed meal. This article introduces the SPUD project, a BBSRC DRINC‐funded initiative. Taking the potato as the model carbohydrate, this project will investigate, via in vitro and in vivo studies, the effects of domestic food processing techniques on the glycaemic response. A final study, utilising intrinsically labelled potato and a dual stable isotope methodology, will model glucose flux data to determine the underlying mechanisms of action.

Postprandial blood glucose response: does the glycaemic index (GI) value matter even in the low GI range?

A growing body of research over the last decades has shown that diets based on the low glycaemic index (GI) foods reduce the risk of developing diabetes and improve blood glucose control in people with diabetes. The range of inflexion on the glycaemic response of low GI (LGI) foods is an interesting observation that has not been studied by many. LGI 1 (GI 54 ± 3.3) biscuit was formulated using a basic formulation while the LGI 2 (23.8 ± 3.3) biscuits was a modification of LGI 1 recipe, formulated with the inclusion of functional ingredients. Biscuits were formulated to be iso-caloric (kcal/100 g: 521 ± 12). Each participant consumed identical standard meals for lunch and dinner. Biscuits were consumed as breakfast and mid-afternoon snack. Using a randomized, controlled, crossover study, 13 males [(means ± SD) age: 25.3 ± 1.0 years, BMI 21.6 ± 0.5 kg/m², fasting blood glucose 4.7 ± 0.1 mmol/L] wore continuous glucose monitoring systems (CGMS™) for 3 days for each test session. The postprandial glycaemic response and insulin response were compared within participants. Total iAUC for breakfast and standard dinner were significantly lower for LGI 2 treatment (p < 0.05) than LGI 1 treatment. Second-meal glucose tolerance was observed at the dinner meal. The overall iAUC insulin response over 180 min was significantly lower for LGI 2 biscuits (p = 0.01). The postprandial glycaemic response of two types of biscuits that fall within the low GI classification (GI 24 and 54) differed with LGI 2 biscuits (GI 24) showing a more suppressed postprandial glycaemic response. Our study shows that even within the low GI range, the GI value matters in influencing postprandial glucose.

Reducing the glycemic impact of carbohydrates on foods and meals: Strategies for the food industry and consumers with special focus on Asia

Type 2 diabetes is increasingly prevalent in Asia, which can be attributed to a carbohydrate-rich diet, consisting of foods in the form of grains, for example, rice, or a food product made from flours or isolated starch, for example, noodles. Carbohydrates become a health issue when they are digested and absorbed rapidly (high glycemic index), and more so when they are consumed in large quantities (high glycemic load). The principal strategies of glycemic control should thus aim to reduce the amount of carbohydrate available for digestion, reduce the rate of digestion of the food, reduce the rate of glucose absorption, and increase the rate of glucose removal from blood. From a food perspective, the composition and structure of the food can be modified to reduce the amount of carbohydrates or alter starch digestibility and glucose absorption rates via using different food ingredients and processing methods. From a human perspective, eating behavior and food choices surrounding a meal can also affect glycemic response. This review therefore identifies actionable strategies and opportunities across foods and meals that can be considered by food manufacturers or consumers. They are (a) using alternative ingredients, (b) adding functional ingredients, and (c) changing processing methods and parameters for foods, and optimizing (a) eating behavior, (b) preloading or co-ingestion of other macronutrients, and (c) meal sequence and history. The effectiveness of a strategy would depend on consumer acceptance, compatibility of the strategy with an existing food product, and whether it is economically or technologically feasible. A combination of two or more strategies is recommended for greater effectiveness and flexibility.

Microstructure-modified products from stone-milled wheat bran powder improve glycemic response and sustain colonic fermentation

Accumulating evidence indicates carbohydrates that escape digestion from upper gastrointestinal tract can reduce glycemic response, enter the colon where they are fermented by the gut microbiota and thus exert multiple healthy benefits to host. A vertical stone milling process was used to prepare a natural wheat bran powder (SWB) containing pericarp, spermoderm, nucellar layer, aleurone layer, germ, and 15% starchy endosperm of wheat kernel, with the result that protein, amylose, and dietary fiber significantly raised comparing to wheat flour (WF). Two types of products, a powdered drink (SWB-D) and a puffed particle (SWB-P), were extruded from SWB, which underwent a gradient of gelatinization and recrystallization with progressively increased resistant starch (RS) content. Starch-protein complexes were detected in SWB-D and SWB-P, concurrently accounting for lower in vitro digestibility and human glycemic response than those of WF noodles. Intake of SWB-D and SWB-P by healthy volunteers elevated level and extended duration of breath hydrogen indicative of higher gut microbiota fermentation. Therefore, RS and starch-protein complexes formed during extrusion reduce digestibility of SWB and sustain colonic fermentation with health-promoting potential targeting the gut microbiota.

Structural Basis of Resistant Starch (RS) in Bread: Natural and Commercial Alternatives

Bread is categorized as having a high amount of rapidly digested starch that may result in a rapid increase in postprandial blood glucose and, therefore, poor health outcomes. This is mostly the result of the complete gelatinization that starch undergoes during baking. The inclusion of resistant starch (RS) ingredients in bread formulas is gaining prominence, especially with the current positive health outcomes attributed to RS and the apparition of novel RS ingredients in the market. However, many RS ingredients contain RS structures that do not resist baking and, therefore, are not suitable to result in a meaningful RS increase in the final product. In this review, the structural factors for the resistance to digestion and hydrothermal processing of RS ingredients are reviewed, and the definition of each RS subtype is expanded to account for novel non-digestible structures recently reported. Moreover, the current in vitro digestion methods used to measure RS content are critically discussed with a view of highlighting the importance of having a harmonized method to determine the optimum RS type and inclusion levels for bread-making.

Predicting Glycemic Index and Glycemic Load from Macronutrients to Accelerate Development of Foods and Beverages with Lower Glucose Responses

Low glycemic index (GI) and/or low glycemic load (GL) are associated with decreased risks of type-2 diabetes and cardiovascular disease. It is therefore relevant to consider GI and GL in the early phases of the development of packaged foods and beverages. This paper proposes a model that predicts GI and GL from macronutrient composition, by quantifying both the impact of glycemic carbohydrates and the GI-lowering effects of nutrients such as proteins, fats and fibers. The precision of the model is illustrated using data on 42 breakfast cereals. The predictions of GI (r = 0.90, median residual = 2.0) and GL (r = 0.96, median residual = 0.40 g) compete well with the precision of the underlying in-vivo data (Standard Error SE = 3.5 for GI). This model can guide product development towards lowering GI and GL, before final confirmation by in vivo testing.

Fish Protein and Lipid Interactions on the Digestibility and Bioavailability of Starch and Protein from Durum Wheat Pasta

This research focussed on the utilisation of salmon protein and lipid to manipulate pasta's glycaemic index and protein digestibility. Salmon fish (Oncorhynchus tschawytscha) powder (SFP) supplemented pasta flour in amounts from 5% to 20% (w/w). Inclusion of SFP lead to a significant reduction in starch digestibility and hence the potential glycaemic values of pasta (experimental pasta being up to 143% lower than control values). SFP addition to pasta increased the release of phenolic compounds from pasta during both gastric digestion (179%) and pancreatic digestion (133%) in comparison to the control sample. At the same time, the antioxidant activity of the digested pasta was increased by up to 263% (gastric) and 190% (pancreatic) in comparison to durum wheat pasta alone. Interestingly, although protein levels increased with incorporation of SFP, the digestibility values of the protein decreased from 86.41% for the control pasta to 81.95% for 20% SFP pasta. This may indicate that there are interactions between phenols and protein in the pasta samples which affect overall protein digestibility levels.

Starch-guest inclusion complexes: Formation, structure, and enzymatic digestion

Starch/amylose-guest inclusion complexes, a class of supramolecular host-guest assemblies, are of critical importance in the processing, preservation, digestion, nutrients/energy uptake, and health outcomes of starch-containing foods. Particularly, the formation of inclusion complex has been suggested to lower the rate and extent of enzymatic digestion of starch and starch-containing foods. Compared with rapidly digestible starch, starch inclusion complex may fall into the category of slowly digestible starch, providing sustained glucose release and maintaining glucose homeostasis. Therefore, the ability of starch-guest inclusion complex to alter the digestive behavior of energy-dense starchy foods has been of interest to many researchers and has the potential to be developed and formulated into functional foods. In this article, we provide a comprehensive and critical review on the current knowledge of the in vitro and in vivo enzymatic digestion of starch-guest inclusion complexes, by emphasizing the structure-digestibility relationship. We examine the preparation methods employed, crystalline structures obtained, and physicochemical properties characterized in previous reports, which all have implications on the digestive behavior reported on the starch-guest inclusion complexes. In addition, we give suggestions on future research to elucidate the digestive properties of starch-guest inclusion complexes and to develop functional structures based on these complexes for use in foods and nutrition.

Ethylcellulose Oleogels: Structure, Functionality, and Food Applications

The structuring edible oils by nontraditional means has become a popular strategy for improving the lipid profile of food products while retaining the functionality of a crystalline triglyceride network. Although numerous oleogelator systems have now been identified, the polymer gelator ethylcellulose (EC) may present the greatest potential for applications in a diverse range of food systems which require unique physical attributes and structuring properties in the fat phase. The first portion of this chapter will provide a brief overview of oleogelation strategies, outline the basic physical characteristics of the polymer EC, and describe the mechanism of gelation and some basic physical characteristics of EC oleogels. The subsequent sections will highlight different strategies which have been identified to manipulate the rheological and mechanical properties of these gels, including the addition of food-grade surfactants and other amphiphilic molecules, modulating bulk solvent polarity, and through the formation of EC/hybrid gelator systems. The final section will highlight various applications in food systems reported in the literature, outline recent work investigating the effect of structuring edible oils with EC on digestibility, and the potential applicability of these oleogels as a delivery vehicle for lipid-soluble molecules. The potential applications for EC oleogels in complex food systems are quite promising, and the strategies for manipulating their physical properties may also extend their applicability into the pharmaceutical, cosmetic, and manufacturing industries.

Lipid droplet size and emulsification on postprandial glycemia, insulinemia and lipidemia

Previous studies have suggested that a smaller lipid droplet size results in a greater rate of lipolysis. However, acute health impacts of emulsification and small lipid droplet size are not well understood. We aimed to investigate the effect of emulsification and lipid droplet size on postprandial lipidemia, glycemia and insulinemia. Fifteen healthy Chinese males (mean ± SD, age of 26 ± 6 years and BMI of 22.2 ± 1.2 kg m^-2) participated on 3 separate occasions in a randomized order. Participants received an olive oil-water beverage and white bread as test meals. The three test beverages were as follows: (1) an olive oil-water mixture (non-emulsified, control), (2) fine olive oil-water emulsion (small lipid droplet size) and (3) coarse olive oil-water emulsion (large lipid droplet size). Glucose, insulin, triglyceride, non-esterified fatty acid (NEFA), gastric antral distention and appetite measurements were recorded for 4 hours. Glucose and insulin concentrations increased rapidly after administration of non-emulsified beverages as compared to fine and coarse emulsions with a significant difference at 30 min (95% confidence interval, P < 0.05). Fine emulsion led to a significant increase in triglyceride responses, a smaller suppression of NEFA responses and slowed gastric emptying compared to the non-emulsified beverage and coarse emulsion (iAUC, 95% confidence interval, P < 0.05). Emulsification and alteration of lipid droplet size have acute effects on glucose, insulin, triglyceride and fatty acid responses.

Effects of liquid oil vs. oleogel co-ingested with a carbohydrate-rich meal on human blood triglycerides, glucose, insulin and appetite

We examine the difference in how coconut oil in a liquid or oleogel form affects blood triglycerides, glucose, insulin, and appetite when co-ingested with a carbohydrate-rich meal.