Characteristics of A/B-type starch-wheat germ oil complexes and their effects on noodle texture

Starch-lipid complexes and their application: A review

The starch-lipid complexes have recently attracted extensive interest due to their excellent properties, such as the decrease of digestibility and the inhibition of starch gelatinization and retrogradation. The review discussed the formation, structure, functionalities and preparation methods of starch-lipid complexes, and most importantly, their application. The starch-lipid complex is classified as a new type of resistant starch-RS5, which can reduce postprandial blood glucose response and regulate human gut health. Over the past few years, starch-lipid complexes have been increasingly reported for applications in food additives, fat substitutes and carriers of nutrients and medicine, regulation of intestinal flora and production of food packaging films. A comprehensive review of applications of starch-lipid complexes is of great importance for understanding and expanding the application of complexes. But the regulatory mechanism of starch-lipid complexes on food quality, food packaging films and intestinal flora is still unclear, which deserves further study in the future. Targeted medicine delivery using starch-lipid complexes may be also a promising and challenging direction in the future.

Lipids-modified starch: Advances in structural characteristic, physicochemical property, and application

Starch and lipids, as two important biomacromolecules in nature, can interact with each other to form a unique complex system during processing, leading to the change of the structural and functional characteristics of starch. The complex formed though the biomacromolecules interaction is a new kind of modified starch named as "lipid-modified starch". At present, the lipids-modified starch has attracted much researchers' attention and become a hotspot topic in food field. This review systematically discusses the different prepared methods (solvent and thermomechanical method) of lipids-modified starch, influence factors of starch-lipids complexation, action mechanism of lipids on starch, as well as the structure, physicochemical properties, digestibility, and applications of lipid-modified starch in recent development. The key findings are summarized as follows: (i) Starch complexed with fatty acids to form V-type inclusion complex, while other lipids (oils and triacylglycerol) are not due to the large spatial structure; (ii) The formation of V-type inclusion complex changed the molecular and crystalline structure, and increased melting temperature and enthalpy of starch, which could be characterized by different analytical technique, such as X-ray diffraction and differential scanning calorimetry; (iii) The properties of starch and lipids, and experimental conditions are key factors in determining the formation of starch-lipid complexes; (iv) Starch-lipids starch can be used as quality improver, fat substitute, resistant starch, carriers of bioactive ingredients in food processing. Finally, the existing problems about the research on lipids-modified starch are discussed to provide new perspectives for the development of this innovative modified starch.

Relationship between internal structure and in vitro digestibility of A- and B-type wheat starch revealed by chemical surface gelatinization

In this study, the properties of remaining starch granules obtained with different degrees of exfoliation were explored by removing the outer layers of A- and B-type wheat starch (AWS and BWS) granules with chemical surface gelatinization. SEM images revealed significant morphological variations with increasing exfoliation. CLSM and amylose content analysis indicated a predominance of lipid complexes in the outer granule layers, particularly in BWS. The structural characteristics of AWS and BWS were analyzed using PLM, XRD, FT-IR and DSC, verifying the conclusion of the alternation of starch crystalline and amorphous zone. And the amorphous regions are proportionally higher in the inner starch layer. Moreover, raw AWS and BWS granules were more easily digested from the outside in, with the RS content decreasing from 80.65 % to 66.92 % and 49.06 % to 45.01 %, respectively. The RS content of cooked WS were affected by the internally structures, particularly lipid content (11.46 % - 19.09 %) in BWS outer layers and amylose content (13.59 % - 19.43 %) in the inner layers. These results revealed the internal radial structural differences and digestibility patterns of AWS and BWS granules.

Potentially Health-Promoting Spaghetti-Type Pastas Based on Doubly Modified Corn Starch: Starch Oxidation via Wet Chemistry Followed by Organocatalytic Butyrylation Using Reactive Extrusion

Extruded spaghetti-type pasta systems were obtained separately either from native or oxidized starch prepared via wet chemistry with the aim of evaluating the effect of oxidation modification of starch. In addition to this, the butyrylation reaction (butyrate (Bu) esterification-short-chain fatty acid) using native or oxidized starch was analyzed under reactive extrusion (REx) conditions with and without the addition of a green food-grade organocatalyst (l(+)-tartaric acid) with the purpose of developing potentially health-promoting spaghetti-type pasta systems in terms of increasing its resistant starch (RS) values. These would be due to obtaining organocatalytic butyrylated starch or not, or the manufacture of a doubly modified starch (oxidized-butyrylated-starch oxidation followed by organocatalytic butyrylation) or not. To this end, six pasta systems were developed and characterized by solid-state ¹³C cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NMR) spectroscopy, degree of substitution (DS), attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), pancreatic digestion, free Bu content analysis and in vitro starch digestibility. The results obtained here suggest that starch oxidation hydrolytically degrades starch chains, making them more susceptible to enzymatic degradation by α-amylase. However, the oxidized starch-based pasta systems, once esterified by Bu mainly on the amylose molecules (doubly modified pasta systems) increased their RS values, and this was more pronounced with the addition of the organocatalyst (maximum RS value = ~8%). Interestingly, despite the checked chemical changes that took place on the molecular structure of starch upon butyrylation or oxidation reactions in corn starch-based spaghetti-type pasta systems, and their incidence on starch digestibility, the orthorhombic crystalline structure (A-type starch) of starch remained unchanged.

Exogenous 6-benzylaminopurine enhances waterlogging and shading tolerance after anthesis by improving grain starch accumulation and grain filling

Due to the frequent occurrence of extreme weather events, the area of wheat affected by continuous cloudy rainfall is increasing, with waterlogging becoming a major limiting factor of wheat yield. To alleviate the effect, spraying exogenous plant growth regulators is often used. In this study, two wheat cultivars, waterlogging-tolerant Yangmai 18 and waterlogging-sensitive Sumai 188, were selected for waterlogging and shading (WS) after anthesis for 7, 11, and 15 days respectively. Three concentrations of 6-benzylaminoadenine (6-BA) solution (15, 25, and 35 mg·L^-1) were sprayed after WS treatment and water was sprayed as the control. Then, the effect of spraying 6-BA on photosynthetic characteristics, starch content, grain filling characteristics, and yield was explored under artificially stimulated continuous cloudy rainfall during anthesis. Compared with the control, the application of 6-BA caused a significant increase in grain plumpness throughout grain filling, as well as increases in the net photosynthetic rate (P _n), stomatal conductance (G _s), and transpiration rate (T _r), and a significant decrease in the intercellular CO₂ concentration (C _i) of the flag leaves, all of which enhanced the photosynthetic capacity. The content of total starch, amylose, and amylopectin in the grains also increased significantly compared with the control. After WS for 15 days, the starch content increased by 3.81%-11.41% compared with the control. Spraying 6-BA also prolonged grain filling, increased the average grain filling rate, and significantly increased the 1000-grain weight and yield. The thousand-grain weight increased by 5.06%-43.28%, and wheat yield increased by 8.93%-64.27% after spraying 25 mg·L^-1 of the 6-BA solution. These findings suggest that the application of 6-BA after WS stress could significantly improve the photosynthetic performance, which is propitious to the accumulation and transport of photosynthetic products after anthesis. Besides, spraying 6-BA can also increase the duration and rate of grain filling and starch accumulation content and improve grain weight, thereby alleviating the adverse effects of WS on wheat yield. Overall, spraying 25 mg·L^-1 of the 6-BA solution had an optimal effect. These findings provide a theoretical basis for the exploration of cultivation techniques and measures aimed at alleviating damage caused by continuous rainfall during wheat anthesis.

Structure and physicochemical properties of cross-linked and acetylated tapioca starches affected by oil modification

This work investigated the structure and physicochemical properties of cross-linked tapioca starch (CTS), acetylated tapioca starch (ATS) and their counterparts (Oil-CTS and Oil-ATS). The results showed oil on the interface of starch granules promoted granule agglomeration after oil modification. Besides, oil modification could increase granule size and destroy the crystalline structure but did not affect the molecular structure of starch. Meanwhile, oil-modified starches did not form the V-type structure like amylose-fatty acid complex, suggesting that oil could not enter the helical cavity of amylose to form complex. Furthermore, compared with CTS and ATS, oil-modified starches had higher shear resistance, lower viscosity and gelatinization enthalpy. Notably, Oil-CTS possessed excellent emulsion stability, with the potential application as an emulsion stabilizer. This study revealed oil modification as an innovative method to endow starch with high shear resistance, low gelatinization enthalpy and excellent emulsion stability to meet the demands of food industries.