Improving physicochemical and nutritional attributes of rice starch through green modification techniques.

Rice, has long been an inseparable part of the human diet all over the world. As one of the most rapidly growing crops, rice has played a key role in securing the food chain of low-income food-deficit countries. Starch is the main component in rice granules which other than its nutritional essence, plays a key role in defining the physicochemical attributes of rice-based products. However, rice starch suffers from weak techno-functional characteristics (e.g., retrogradability of pastes, opacity of gels, and low shear/temperature resistibility. Green modification techniques (i.e. Non-thermal methods, Novel thermal (e.g., microwave, and ohmic heating) and enzymatic approaches) were shown to be potent tools in modifying rice starch characteristics without the exertion of unfavorable chemical reagents. This study corroborated the potential of green techniques for rice starch modification and provided deep insight for their further application instead of unsafe chemical methods.

Ionizing and nonionizing radiations can change physicochemical, technofunctional, and nutritional attributes of starch.

Challenges for the food/non-food applications of starch mostly arise from its low stability against severe processing conditions (i.e. elevated temperatures, pH variations, intense shear forces), inordinate retrogradability, as well as restricted applicability. These drawbacks have been addressed through the modification of starch. The escalating awareness of individuals toward the presumptive side effects of chemical modification approaches has engrossed the attention of scientists to the development of physical modification procedures. In this regard, starch treatment via ionizing (i.e. gamma, electron beam, and X-rays) and non-ionizing (microwave, radiofrequency, infrared, ultraviolet) radiations has been introduced as a potent physical strategy offering new outstanding attributes to the modified product. Ionizing radiations, through dose-dependent pathways, are able to provoke depolymerization or cross-linking/grafting reactions to the starch medium. While non-ionizing radiations could modify the starch attributes by changing the morphology/architecture of granules and inducing reorientation/rearrangement in the molecular order of starch amorphous/crystalline fractions.

Starch modification through its combination with other molecules: Gums, mucilages, polyphenols and salts.

Apart from its non-toxicity, biocompatibility and biodegradability, starch has demonstrated eminent functional characteristics, e.g., forming well-defined gels/films, stabilizing emulsions/foams, and thickening/texturizing foods, which make it a promising hydrocolloid for various food purposes. Nonetheless, because of the ever-increasing range of its applications, modification of starch via chemical and physical methods for expanding its capabilities is unavoidable. The probable detrimental impacts of chemical modification on human health have encouraged scientists to develop potent physical approaches for starch modification. In this category, in recent years, starch combination with other molecules (i.e., gums, mucilages, salts, polyphenols) has been an interesting platform for developing modified starches with unique attributes where the characteristics of the fabricated starch could be finely tuned via adjusting the reaction parameters, type of molecules reacting with starch and the concentration of the reactants. The modification of starch characteristics upon its complexation with gums, mucilages, salts, and polyphenols as common ingredients in food formulations is comprehensively overviewed in this study. Besides their potent impact on physicochemical, and techno-functional attributes, starch modification via complexation could also remarkably customize the digestibility of starch and provide new products with less digestibility.

Sorghum Flour Application in Bread: Technological Challenges and Opportunities.

Sorghum has a long history of use in the production of different types of bread. This review paper discusses different types of bread and factors that affect the physicochemical, technological, rheological, sensorial, and nutritional properties of different types of sorghum bread. The main types of bread are unleavened (roti and tortilla), flatbread with a pre-ferment (injera and kisra), gluten-free and sorghum bread with wheat. The quality of sorghum flour, dough, and bread can be improved by the addition of different ingredients and using novel and traditional methods. Furthermore, extrusion, high-pressure treatment, heat treatment, and ozonation, in combination with techniques such as fermentation, have been reported for increasing sorghum functionality.

Recent strategies for tackling the problems in gluten-free diet and products.

The gluten-free food market is growing with the increases in the number of people who adhere to gluten-free diet. The noteworthy increase in the number of people following a gluten-free diet may be associated to the diagnosis of many silent and subclinical celiac disease cases, improved knowledge of celiac disease, gluten allergy or gluten sensitivity as well as to popular belief that gluten-free diet is healthier. Despite the increase in the number of people following a gluten-free diet, the lack of awareness and knowledge about gluten-free diet generates problems for non-celiac people who are considering that gluten-free products are healthier as well as for celiac people who have to follow gluten-free diet. Notwithstanding the increasing interest in adopting gluten-free diet, there are still important obstacles affecting the adherence to gluten-free diet. The limited availability, high price of products, insufficient labeling, cross-contamination risk, treatment burden, lack of knowledge and information about celiac disease and about gluten-free diet, psychological factors in celiac patients, the adverse effects of a gluten-free diet and quality defects of gluten-free products are among the major problems that faced by celiac patients. In this perspective, the aim of this review is to provide an overview of important challenges in the maintenance of a strict gluten-free diet that faced by celiac patients during the adherence to gluten-free diet and related approaches have been able for tackling the problems.

Recent developments of oleogel utilizations in bakery products.

Available evidence from clinical trials suggests the replacement of saturated fatty acids with polyunsaturated fatty acids as well as with essential fatty acids to reduce the risk of coronary heart disease. Thus, the importance of limiting of saturated fatty acid intake as well as the removal of trans-fatty acids from the diet have also emphasized. Conversely, recent studies have questioned the simple explanation of the relationship of dietary saturated fats and of individual saturated fatty acids to cardiovascular disease. Although, controversies continue to exist, current recommendations have highlighted that the importance of a critical look at the evaluation of scientific understanding about dietary fats and health. Therefore, manufacturers and scientists have focused on seeking alternative ways to modify or structure liquid oil without the use of saturated and trans-fats and hence to offer the functionality of fats to food products without changing the nutritional profile of liquid oil. However, since shortening as the essential component of bakery products affects dough structure and the desired final product attributes, the replacement of shortening creates a big challenge in bakery problems. The aim of this study was to provide an overview of the functions of shortening in bakery products and of the field of oleogels with special importance on the updates from recent years and their possible applications in bakery products. With the incorporation of oleogels or oleogel/shortening blends, rheological properties of dough/batters as well as physicochemical properties of resulted products may be resembled to those made with shortening. Conversely, the application of this technique had a role on retaining solid-like properties while possesses a healthier fatty acid profile. Very recent study indicated that gradual replacement of shortening with oleogels have potential for partial reduction of saturated fat without chancing physical properties of gluten free aerated products. Thus, the applications of oleogels may also present more alternatives for celiac sufferers' diet.

Reducing saturated fat with oleogel/shortening blends in a baked product.

Short dough cookie structure, characterized by its aerated and tender texture, depends on the presence of solid fat during kneading. The objective of this study was to investigate the potential application of Candelilla wax (CDW) containing oleogels for partial replacement of the shortening in cookies. Oleogels were prepared with different amounts of CDW and blended with a commercial bakery shortening. After crystallizing the oleogel/shortening blends by using a pilot scale crystallization unit, the blends were evaluated in a cookie formulations. When the shortening was completely replaced with oleogel softer products were obtained compared to liquid oil, but they were harder than the shortening containing products. On the other hand, partial replacement of shortening with oleogels provided much more acceptable dough and cookie characteristics. Results suggest that gradual replacement of shortening with oleogels may be a suitable approach for reduction of saturated fat in short dough products.