A Review of the Design and Architecture of Starch-Based Dietary Foods

Carbohydrates,which are mostly present in sugar,starch,and fiber,are one of the main ingredients of food and the primary source of energy in the human diet.Among these three main sources,starch stands out as one of the most abundant reserves of carbohydrates.Investigating starch would not only enhance our understanding of the functionality of starch in the human body but also aid in the design of novel starch-based dietary foods.The present review first provides a state-of-the-art understanding of the various classifications of dietary starches,including rapidly digesting starch(RDS),slowly digesting starch(SDS),and resistant starch(RS).Moreover,both the in vivo and in vitro determination methods of the digestibility of starch-based dietary foods are discussed.Based on the current understanding,present research strategies to design novel starch-based dietary foods through either the direct addition of modified starch or the alteration of processing conditions are highlighted.Furthermore,certain perspectives related to the future research directions of starch-based foods are also included.

novel amylolytic enzyme from Palaeococcus ferrophilus with malto-oligosaccharide forming ability belonging to subfamily GH13_20

By heterologous expression of a gene from Palaeococcus ferrophilus,a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics.The optimal temperature and pH of AMPf were 50℃ and 7.0 respectively.Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20,interestingly,this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily.AMPf hydrolyzes starches to glucose,maltose,maltotriose,and maltotetrose as main products.AMPf mainly liberates glucose from starch with the concentration of 1%(w/v),while it shows malto-oligosaccharide forming ability with higher starch concentration of 4%(w/v).Also,the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf.AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity.It was proven AMPf has application protential in malto-oligosaccharides production.