Dual modification of potato starch: Effects of heat-moisture and high pressure treatments on starch structure and functionalities

Optimization of ultrasonic-assisted enzymatic extraction of kiwi starch and evaluation of its structural, physicochemical, and functional characteristics

A new ultrasound-assisted enzymatic extraction (UAEE) method of starch from kiwifruit was established and optimized using response surface methodology (RSM). Under optimal conditions (the pectinase-to-cellulase-to-papain ratio = 1:2:1 g/kg, solid/liquid ratio = 1:6.68, extraction pH = 5.23, ultrasound power = 300 W, and extraction temperature = 52 °C), the kiwi starch (KS) yield was about 4.25%, and the starch content of KS was 873.23 mg/g. Compared to other extraction methods, UAEE can obtain KS with high yield and purity with a shorter extraction time and less solvent and enzyme. The extracted KS has a low gelatinization enthalpy (8.02 J/g) and a high peak viscosity (7933 cP), with obvious particle properties and low adhesion. In addition, KS is rich in polyphenols, has strong antioxidant activity, and has higher contents of amylose starch (30.74%) and resistant starch (60.18%). This study established a novel and highly efficient method for KS extraction and suggest several possible applications for KS in the food industry.

Analysis of the sol and gel structures of potato starch over a wide spatial scale

We analyzed edible potato starch and observed the interaction between its granular structure and water molecules. We studied the changes caused by gelatinization during heating and stirring using microscopy, micro-FT-IR spectroscopy, and X-ray scattering techniques. A wide range of spatial scales was revealed using these various techniques. The rate of gelatinization varied significantly and was dependent on the starch concentration. The process of adsorption of water on starch molecules was studied using the humidity-controlled FT-IR spectroscopy technique. Furthermore, by comparing the X-ray scattering profiles of dry and wet granules, the 9-nm repeat "cluster" structure was studied. A gradual collapse of the granules occurred during the processes of heating and stirring. A clustered smectic structure and a smectic-like structure were observed in the opaque gel after gelatinization. Upon further heating, a transparent gel was obtained after the melting of the cluster.

Modifying Effects of Physical Processes on Starch and Dietary Fiber Content of Foodstuffs

Carbohydrates are one of the most important nutrients in human consumption. The digestible part of carbohydrates has a significant role in maintaining the energy status of the body and the non-digestible parts like dietary fibers have specific nutritional functions. One of the key issues of food processing is how to influence the technological and nutritional properties of carbohydrates to meet modern dietary requirements more effectively, considering particularly the trends in the behavior of people and food-related health issues. Physical processing methods have several advantages compared to the chemical methods, where chemical reagents, such as acids or enzymes, are used for the modification of components. Furthermore, in most cases, these is no need to apply them supplementarily in the technology, only a moderate modification of current technology can result in significant changes in dietary properties. This review summarizes the novel results about the nutritional and technological effects of physical food processing influencing the starch and dietary fiber content of plant-derived foodstuffs.

Combination treatment of bamboo shoot dietary fiber and dynamic high-pressure microfluidization on rice starch: Influence on physicochemical, structural, and in vitro digestion properties

The physicochemical, structural properties and digestibility of rice starch treated by bamboo shoot dietary fiber (BSDF) combined with dynamic high-pressure microfluidization (DHPM) were investigated. Compared with starch modified by BSDF alone, the combination treatment decreased the pasting viscosity and viscoelasticity of starch. Furthermore, the pasting viscosity and viscoelasticity showed an increase from 50 to 100 MPa and then decreased after increasing the pressure to 150 and 200 MPa. The enthalpy of gelatinization and relative crystallinity of starch treated by BSDF and 100 MPa DHPM significantly increased by 17% and 63%, respectively. Scanning electron microscopy images demonstrated that flaky BSDF coated on starch granules to form a protective layer. As a result, the fractions of resistant starch increased and the starch hydrolysis extent and rate decreased under 100 MPa DHPM. This study highlights an innovative and promising strategy for improving the properties of starch and facilitating its utilization.

Recent advances in heat-moisture modified cereal starch: Structure, functionality and its applications in starchy food systems

Cereals, one of the starch sources, have a tremendous and steady production worldwide. Starchy foods constitute the major part of daily calorie intake for humans. As a simple and green modification approach, heat-moisture treatment (HMT) could change the granular surface characteristics and size, crystalline and helical structure, as well as molecular organization of cereal starch. The changing degree is contingent on HMT parameters and botanical origin. Based on the hierarchical structure, this paper reviews functionalities of heat-moisture modified cereal starch (HMCS) reported in latest years. The functionality of HMCS could be affected by co-existing non-starch ingredients through non-covalent/covalent interactions, depolymerization or simply attachment/encapsulation. Besides, it summarizes the modulation of HMCS in dough rheology and final food products' quality. Selecting proper HMT conditions is crucial for achieving nutritious products with desirable sensory and storage quality. This review gives a systematic understanding about HMCS for the better utilization in food industry.

Insight into the biphasic transition of heat-moisture treated waxy maize starch through controlled gelatinization

Biphasic transition is an important behavior of starch caused by heat-moisture treatment (HMT). Starch may change from typical single endotherm to biphasic endotherm (G1, G2) by HMT which corresponded to two viscosity peaks (PV₁ and PV₂) in pasting analysis. During PV₁, remarkable disruption of birefringence occurred in the inner region of starch granules, accompanied by a decreased relative crystallinity from 20.59 to 14.73%. Native starch completely lost their birefringence at 73 °C, while the HMT starch still showed strong birefringence in granule periphery. The HMT starch only lost crystallites at 80 °C (PV₂). A crystallite stability hypothesis was developed that G1 was mainly due to the gelatinization of the inner crystalline lamellae of starch granule, and the newly formed G2 was caused by the peripheral ones enhanced by HMT. This work also provided details on the mechanism of HMT and a potential method for the thermal transition study on starch.

Effect of Ultrasonic and Microwave Dual-Treatment on the Physicochemical Properties of Chestnut Starch

This work examined the effect of ultrasound and microwave treatments, separate and in combination, on the physicochemical and functional properties of chestnut starch. The results revealed that the ultrasonic-microwave (UM) and microwave-ultrasonic (MU) dually modified samples exhibited more severe surface damage, weaker birefringence, and lower relative crystallinity and gelatinization enthalpy than the native and single-treated starches. The UM samples showed the highest oil absorption capacity, and the MU samples showed the highest water absorption capacity and the best freeze-thaw stability (five cycles) among all samples. The swelling power, peak, trough, final, and breakdown viscosities, and pasting temperature all decreased regardless of single or dual modification. This study provides a reference for potential industrial applications of ultrasound and microwave treatments for the modification of chestnut starch.

A Review on the Effect of High Pressure Processing (HPP) on Gelatinization and Infusion of Nutrients

High pressure processing (HPP) is a novel technology that involves subjecting foods to high hydrostatic pressures of the order of 100-600 MPa. This technology has been proven successful for inactivation of numerous microorganisms, spores and enzymes in foods, leading to increased shelf life. HPP is not limited to cold pasteurization, but has many other applications. The focus of this paper is to explore other applications of HPP, such as gelatinization, forced water absorption and infusion of nutrients. The use of high pressure in producing cold gelatinizing effects, imparting unique properties to food and improving food quality will be also discussed, highlighting the latest published studies and the innovative methods adopted.