Ball-milling: A sustainable and green approach for starch modification.

Ball-milling is a low-cost and green technology that offers mechanical actions (shear, friction, collision, and impact) to modify and reduce starch to nanoscale size. It is one of the physical modification techniques used to reduce the relative crystallinity and improve the digestibility of starch to their better utility. Ball-milling alters surface morphology, improving the overall surface area and texture of starch granules. This approach also can improve functional properties, including swelling, solubility, and water solubility, with increased energy supplied. Further, the increased surface area of starch particles and subsequent increase in active sites enhance chemical reactions and alteration in structural transformations and physical and chemical properties. This review is about current information on the impact of ball-milling on the compositions, fine structures, morphological, thermal, and rheological characteristics of starch granules. Furthermore, ball-milling is an efficient approach for the development of high-quality starches for applications in the food and non-food industries. There is also an attempt to compare ball-milled starches from various botanical sources.

Starch-based noodles: Current technologies, properties, and challenges.

Starch noodles are gaining interest due to the massive popularity of gluten-free foods. Modified starch is generally used for noodle production due to the functional limitations of native starches. Raw materials, methods, key processing steps, additives, cooking, and textural properties determine the quality of starch noodles. The introduction of traditional, novel, and natural chemical additives used in starch noodles and their potential effects also impacts noodle quality. This review summarizes the current knowledge of the native and modified starch as raw materials and key processing steps for the production of starch noodles. Further, this article aimed to comprehensively collate some of the vital information published on the thermal, pasting, cooking, and textural properties of starch noodles. Technological, nutritional, and sensory challenges during the development of starch noodles are well discussed. Due to the increasing demands of consumers for safe food items with a long shelf life, the development of starch noodles and other convenience food products has increased. Also, the incorporation of modified starches overcomes the shortcomings of native starches, such as lack of viscosity and thickening power, retrogradation characteristics, or hydrophobicity. Starch can improve the stability of the dough structure but reduces the strength and resistance to deformation of the dough. Some technological, sensory, and nutritional challenges also impact the production process.

Enzymatic modification of starch: A green approach for starch applications.

Native starches are modified to overcome the shortcoming, including retrogradation, syneresis, and low water-holding potential, which limit their industrial applications. The enzymatic modification includes designing a starch with a new structure. The molecular mass, branch chain-length distribution, and amylose/amylopectin ratio can be altered by enzymatic reactions when the enzymes react with gelatinized starch. The enzymatic modification directly affects the properties of the modified starch, including in freeze-thaw stability of gels and retardation of retrogradation during storage. Various enzymatic modifications of starch have been attempted for novel applications to the food industry as food ingredients, the enhancement of product quality, and the improvement of the efficiency of food processing. This review article addresses the key enzymes used for starch modifications, their mechanism of action, functionality and discusses new challenges and opportunities for effective modification. Also, the current review will give a critical snapshot of the applications for starch modifications in food industries.

Proso-millet starch: Properties, functionality, and applications.

Previously proso-millet, considered an underutilized cereal, has drawn considerable attention due to health benefits like good nutritional profile, low glycemic index, and gluten-free. The present review discusses starch extractability, structural characteristics, morphology, and physicochemical properties. Starch properties mainly depend on the amylose and amylopectin composition and distribution of brained chains. A very diverse starch structure and morphology were observed among the waxy and non-waxy cultivars. The amylose content ranged from 0.75 to 28.3% in many varieties, but exceptionally Hongmeizi variety showed a 32.3% as per the reported evidence. There are a positive correlation between the amylose content and cooking quality, thermal and pasting properties. The size and shape of smallest to largest starch granules varied between 0.3 and 17 µm and round to polygonal, respectively. The non-waxy starch varieties of proso-millet are widely used in food processing due to high resistance to swelling during heat treatment. Few food applications of proso-millet are bakery products like gluten-free bread, porridge, pasta, ready-to-eat breakfast cereals, infant foods, and distilleries. We can conclude that proso millet is an alternative to existing starch for its quality characteristics and provides insight to many food processing industries.

Dual modification of various starches: Synthesis, properties and applications.

The problems associated with native starches (NSs) and single modified starches were stated in order to justify dual modification of various starches. Broadly, there are two types of dual modification, i.e., homogeneous dual modification and heterogeneous dual modification. The combination of two physical modifications, e.g., (extrusion/annealing); two chemical modifications, e.g., (succinylation/cross-linking) and two enzymes modification (α-amylase/pullulanase) falls under the former classification and the latter classification is the combination of two of each of the differently stated modifications, e.g., acetylation/annealing, extrusion/succinylation, and microwave-assisted phosphorylation, etc. The classification, synthesis, properties and applications of dually modified starches were discussed. There is an attempt to elucidate the problems of each of the single modification in order to justify dual modifications. In dual modifications, the order of reactions, the reaction conditions, the medium of reaction, and the botanical sources of the various starches are very important parameters.

Developments in the isolation, composition, and physicochemical properties of legume starches.

The purpose of this write-up is to discuss the recent developments in the study of the physicochemical and functional properties of legume starches. Legumes are abundantly rich in proteins, polysaccharides, vitamins, and minerals. Starch is the most important polysaccharide in the human diet. The amylose, lipid, ash, and nitrogen content of legume starches vary in the range of 18-52%, 0.1-0.9, 0.0-0.7%, and 0.0-0.3%, respectively. The legume starches are characteristically rich in amylose, display limited swelling power, poor dispersibility in water, and vulnerable to retrogradation. The properties of legume starches reveal that they possess strong bonding chains between its molecules. Due to these strong bonds, legume starches have high gelatinization transition temperatures and enthalpies. Furthermore, the pasting properties are in accordance with this concept. Legume starches differ in granule morphology, gelatinization transition temperatures, and amylose content. There is need for modification of legume starches due to poor functionality such as easy vulnerability to retrogradation and poor processing properties when subjected to extreme of conditions. These shortcomings of legume starches are usually mitigated by annealing, heat-moisture treatment, cross-linking, acid-thinning, oxidation, and acetylation. This review highlighted developments in the isolation, composition, morphology, physicochemical properties, and some aspect of physical and chemical modification of legume starches.