Thermal behavior of resistant starches RS 2, RS 3, and RS 4

Application of microwave and hydrothermal treatments for modification of cassava starch of Manipur region, India and development of cookies

The cassava (Manihot esculenta) root provides sustainable cheap source of starch that can be modified using microwave and hydrothermal treatments. The modified starch is of great demand in the market for its varied food applications. The microwave modified wet milling dry chips starch, microwave modified pulp starch (MD-PS), microwave modified dry chips starch were the microwave treated starch obtained from starches of pulp starch (PS), wet milling dry chips starch and dry milling dry chips starch, respectively. On the other hand, by using hydrothermal treatment followed by freeze-drying in PS gave autoclave freeze-dried 10% PS (AF-10PS), autoclave freeze-dried 20% PS (AF-20PS). The physicochemical and functional properties of the samples were investigated. The calorific value of modified starch was found to be 341-358 kcal/100 g. The microwave-modified starch lowered true densities as compared to hydrothermal treated starch. FT-IR spectra of microwave-modified starch confirmed six prominent peaks between 4500-500 cm^-1. Thermal treatment affected the digestibility and found lower digestion resistibility in modified starch compared to native starch. The structures of the starch granules were more enzymatically susceptible in hydrothermally modified starch. The microwave-modified starch resulted higher resistant starch as compared to hydrothermally modified starch. The cookies quality using MD-PS was checked by developing with 10-40% level of substitution of wheat flour. Overall cookies acceptability was found above sensory score 5. This study will help to provide functional ingredients that serve health benefit beyond nutrition.

Edible coatings and films with incorporation of prebiotics -A review

Prebiotics are compounds naturally present in some foods or can be synthesized by microorganisms and enzymes. Among the benefits associated with prebiotic consumption are the modulation of the intestinal microbiota that increase the production of short chain fatty acids and prevent the development of some disorders such as colon cancer, irritable bowel syndrome, diabetes, obesity, among others. Traditionally, prebiotics have been used in diverse food formulations to enhance their healthy potential or to improve their technological and sensory properties. However, different alternatives for the production of prebiotic products are being explored, such as edible coatings and films. Therefore, this review aims to highlight recent research on edible coatings and films incorporated with different prebiotics, the concept of prebiotics, the general characteristics of these materials, and the main production methods, as well as presenting the perspectives of uses in the food industry. Current works describe that polyols and oligosaccharides are the most employed prebiotics, and depending on their structure and concentration, they can also act as film plasticizer or reinforcement agent. The use of prebiotic in the coating can also improve probiotic bacteria survival making it possible to obtain fruits and vegetables with synbiotic properties. The most common method of production is casting, suggesting that other technologies such as extrusion can be explored aiming industrial scale. The use of film and coating carried of prebiotic is an emerging technology and there are still several possibilities for study to enable its use in the food industry. This review will be useful to detect the current situation, identify problems, verify new features, future trends and support new investigations and investments.

Effect of 2 types of resistant starches on the quality of yogurt

This study investigated the effects of resistant starch (RS) 2 (a high-amylose corn starch) and RS3 (physically modified corn starch) on yogurt quality. Yogurt containing Bifidobacterium BB-12 was treated with RS2 or RS3 to a final concentration of 1.5%, with the control group receiving 1.5% (wt/wt) of sucrose. Multispeckle diffusing wave spectroscopy and scanning electron microscopy were used to investigate the effect of the resistant starches on the gelation process and microstructure of yogurt. The quality of the yogurt treatments was evaluated using viable counts of Bifidobacterium BB-12 and all viable cells, titratable acidity, amount of whey separation, and viscosity during storage. The resistant starches affected the progress of gelation and microstructure and decreased the decline of viable counts of Lactobacillus. Notably, RS3 effectively protected the Bifidobacterium BB-12, increased the viscosity, and decreased titratable acidity. Our results suggested that RS could improve the quality of yogurt and have a more probiotic effect. Further studies could lead to optimization in yogurt processing by mixing these 2 types of RS to determine their best usage and explore their interactions with proteins.

The effect of various cooking methods on resistant starch content of foods

Purpose

Resistant starch, defined as all starch and starch-degradation products not absorbed by small intestine of healthy individuals, is included in the diet of individuals due to its prebiotic characteristics and protective effects against diseases like colon cancer, type II diabetes, obesity and cardiovascular diseases. Some cooking methods are known as effective on resistant starch content of foods. The purpose of this paper is to explore the effect of various cooking methods on resistant starch content of foods.

Design/methodology/approach

Potential health benefits and functional features of the resistant starch have been emphasized in the recent years. This review includes up-to-date scientific findings in different studies on the effect of various cooking methods on resistant starch content of foods. Advantages and nutritional quality of resistant starch are included to topic.

Findings

Cooking methods including baking, steaming and autoclave cooking increased the amount of the resistant starch of foods, but cooking method such as pressure cooking decreased the amount of the resistant starch of foods. Boiling, frying, microwave cooking and extrusion cooking have the potential of increasing the amount of resistant starch, which depends on the source of starch and the process conditions. Although frying method has a high potential to increase the resistant starch content of foods, it is inconvenient to recommend frying to modify resistant starch content of foods due to detrimental effects of frying and products on health.

Originality/value

This paper focuses on the effects of various cooking methods on resistant starch content of foods, which offers a promising future for the inartificial development of the prebiotic content of diet. Due to its potential health benefits, appropriate cooking methods should be preferred to increase resistant starch content of foods.

Effect of different fibers on dough properties and biscuit quality

BACKGROUND

This study forms part of a broader project aimed at understanding the role of fibers from different sources in high-fat, high-sugar biscuits and at selecting the best fibers for biscuit quality. The main purpose of this work was to understand the rheological and structural properties involved in fiber-enriched biscuit dough. High-amylose corn starch (RSII), chemically modified starch (RSIV), oat fiber (OF) and inulin (IN) were used at two different levels of incorporation (6 and 12 g) in dough formulation. The influence of fiber on the properties of biscuit dough was studied via dynamic rheological tests, confocal microscopy and spreading behavior. Biscuit quality was assessed by width/thickness factor, texture and surface characteristics, total dietary fiber and sensory evaluation.

RESULTS

Main results indicated that IN incorporation increased the capacity of dough spreading during baking and thus improved biscuit quality. OF reduced dough spreading during baking and strongly increased its resistance to deformation. RSII and RSIV slightly affected the quality of the biscuits. Sensory evaluation revealed that the panel liked IN-incorporated biscuits as much as control biscuits.

CONCLUSION

The increase in total dietary fiber modified dough behavior and biscuit properties, and the extent of these effects depended on the type of fiber incorporated. © 2016 Society of Chemical Industry.

Functional Properties and Postharvest Utilization of Commercial and Noncommercial Banana Cultivars

Banana (Musa spp.) is one of the world's most important crops cultivated in tropical and subtropical regions of the world. Banana is a major source of macro-elements, especially potassium, and contains health-beneficial ingredients such as resistant starch, total dietary fibers, rapidly digestible starch, and slowly digestible starch. Oligosaccharides (fructooligosaccharides and inulin) and polyphenols ((+)-catechin, (-)-epicatechin, (-)-epigallocatechin, and gallic acid) are other ingredients present in bananas that have found application in the prevention of muscular contractions, regulation of blood pressure, prevention of colon cancer and diabetes, and in the cure of intestinal disorders when unripe. This review identifies the different commercial and noncommercial banana cultivars and their utilization. Commercial cultivars include Williams (M. acuminata cv. Williams), Dwarf Cavendish (M. acuminata cv. Petite Nain), Chinese Cavendish (M. acuminata cv. Chinese Cavendish), Grand Nain (M. acuminata cv. Grand Nain), and Goldfinger (M. acuminata cv. Goldfinger), with Mabounde and Luvhele identified as noncommercial varieties. Banana postharvest utilization includes its use as functional foods, prebiotics, probiotics, nutraceuticals, and processing into value-added products.

A 90-day toxicology study of high-amylose transgenic rice grain in Sprague-Dawley rats

A transgenic rice line (TRS) with high amylose level has been developed by antisense RNA inhibition of starch branching enzymes. Compositional analysis of TRS demonstrated that the content of resistant starch (RS) was significantly higher compared to conventional non-transgenic rice. High level of RS is an important raw material in food industry and has various physiological effects for human health. In order to provide the reliable theory basis for field release of TRS rice, we evaluated the potential health effects of long-term consumption of the TRS. The 90-day toxicology feeding experiment was conducted in Sprague-Dawley rats fed with diets containing 70% of either TRS rice flour, its near-isogenic rice flour or the control diet. The clinical performance variables (body weight, body weight gain and food consumption) were measured and pathological responses (hematological parameters and serum chemistry at the midterm and the completion of the experiment, urinalysis profile and serum sex hormone response at the completion of the experiment) were performed. Besides, clinical signs, relative organ weights and microscopic observations were also compared between TRS group and its near-isogenic rice group. The combined data indicates that high-amylose TRS grain is as safe as the conventional non-transgenic rice for rat consumption.

Review: Starch Matrices and the Glycemic Response

Starch is the most important source of energy for humans, and it is present in many products derived from cereals, legumes and tubers. Interestingly, some of these food products can have different metabolic effects (e.g. change of postprandial blood glucose concentration) although the total amount of starch is the same. This review focuses on a microstructural perspective of the glycemic response, in search of an alternative and complementary explanation of this phenomenon. Several starch and food microstructures are responsible for the change in starch bioaccessibility. Aspects such as the characterization of the microstructure of starchy products and, its relation to the metabolic problem, the crucial role of the food matrix and other components in the ingested meal, and the gaps in our present knowledge are discussed.

Different types of resistant starch elicit different glucose reponses in humans

The purpose of this study was to determine whether different types of resistant starch (RS) elicited different glycemic responses. Eleven healthy subjects consumed solutions containing 30 g of either dextrose (DEX), resistant starch type 2 (RS2), or cross-linked resistant wheat starch type 4 (RS4(XL)) on three separate occasions, which were assigned randomly. Finger stick blood samples were collected before and over the following two hours and measured for glucose. The incremental area under the curve (iAUC) for the glucose response was calculated for all trials. The two types of resistant starch significantly (P < .05) decreased iAUC compared with DEX. The response with RS4(XL) was significantly decreased compared with the RS2 trial. These data demonstrate that different types of resistant starch elicit significantly different glycemic responses.