New insights into starch gelatinization by high pressure: Comparison with heat-gelatinization

Can agriculture and food waste be a solution to reduce environmental impact of plastic pollution? zero-waste approach for sustainable clean environment

Agriculture and food waste, especially from fruits, vegetables, and plant byproducts like banana peels, avocado seeds, and durian seeds, have emerged as promising alternatives for bioplastic production. These materials, rich in polysaccharides and cellulose, offer a sustainable solution to reduce plastic pollution and mitigate the environmental impact of traditional plastics. This review focuses on the potential of utilizing agricultural and food waste to create starch-based bioplastics, emphasizing the importance of a zero-waste approach to enhance the economic value of these byproducts while promoting a cleaner environment. We include a SWOT analysis of this innovative approach, assess the environmental implications of bioplastic production, and highlight the potential for turning agricultural waste into a key player in the fight against plastic pollution. This review also explores the future prospects of harnessing agriculture and food waste as valuable resources for sustainable bioplastics, contributing to a greener, more sustainable world.

Characterization of dynamic of the structural changes of legume starches during gelatinization

This study investigated the dynamic changes in legume starches (common vetch, mung bean, and pea) during gelatinization. All three starches displayed a similar pattern: water absorption and swelling at lower temperatures (50-65 °C), structural rupture at medium temperatures (65-75 °C), and melting/reorganization at higher temperatures (75-90 °C). Gelatinization likely starts with internal structural dissociation, as evidenced by the weakening of the double helix structure and decreasing order observed throughout the process. Lamellar analysis further revealed that the amorphous region swelled first, followed by swelling and melting of the crystalline region. Interestingly, the resulting mutual melting system exhibited varying density, with mung bean starch showing the highest density, followed by pea starch and common vetch starch being the least dense. These findings contribute to a deeper understanding of morphological and structural transformations occurring within legume starches during gelatinization.

New insight into amino acids on the structure and rheological properties of rice starch via ultra-high pressure processing

There is a lack of research on the effects of amino acid starch interaction on the functional properties of products during Ultra-high pressure (UHP) processing. The functional properties of rice starch with the addition of Glu, Ala and Lys were studied under UHP processing. At 400 MPa, all amino acids reduced G' and weakened the gel strength, and the gel strength order was as follows: Control > Ala > Glu > Lys. At 500 MPa, Glu increased G' and G″, and enhanced the strength of the gel, but the addition of Lys had the opposite effects, the gel strength order was as follows: Glu > Ala > Control > Lys. With the increased of treatment pressure and time, the G' and G″ of all samples treated at 500 MPa decreased, and the gel strength weakened. This study will expand the application scope of rice starch as food gelling agents and functional food.

Enhancing enzymatic resistance of pea type 3 resistant starch through pressure heating and annealing

Type III resistant starch (RS3) is an important functional food ingredient. In this study, RS3 was prepared by retrogradation of pea starch after acid hydrolysis and pullulanase debranching. Heat-moisture treatments, including annealing (90 °C, 40-70 % moisture content) and pressure heating (121 °C, 10-40 % moisture content), were employed to further enhance the RS content of pea RS3. The relationship between the structural changes and digestibility of pea RS3 was investigated. The results showed significant increases in relative crystallinity, particle size, gelatinization temperature, and RS content, while swelling power, pasting viscosity, and rapidly digestible starch content were markedly decreased after heat-moisture treatment. A strong positive correlation (r = 0.94*) was observed between relative crystallinity and RS content. The highest RS content of 85.6 % was achieved after pressure heating at 20 % moisture content, which was notably higher than the 45.6 % RS content before heat-moisture treatment. This study highlights the beneficial effects of annealing and pressure heating in enhancing RS content in pea RS3, providing valuable insights for developing RS3 with high RS content after cooking.

Effects of glycosylated whey protein isolate on gelatinization, gel properties, and microstructure of wheat starch

Glycated whey protein isolate (gWPI) was produced by dry thermal reaction between whey protein isolate (WPI) and lactose, and its influence on the gelatinization, gel properties, and microstructure changes of wheat starch (WS) was systematically studied. Results showed that gWPI significantly inhibited starch gelatinization and improved starch gel properties. RVA and DSC analysis showed that gWPI decreased viscosity and gelatinization enthalpy (ΔH) in a concentration-dependent manner. When gWPI concentration was 12 %, the peak viscosity and ΔH decreased by 36 cP and 3.11 J/g, respectively. gWPI competed with WS for water and inhibited WS water absorption and expansion. Rheological results showed that the viscoelasticity of the gel decreased by adding gWPI and that of WS-gWPI was a pseudoplastic fluid with shear-thinning behavior. In addition, gWPI covered the WS surface in the form of hydrogen bonds, which inhibited the leaching of amylose, thereby reducing the particle size of the gelatinized starch and its iodine binding ability. AFM results showed that gWPI combined with WS weakened the aggregation of starch molecular chains and decreased the height of starch. In conclusion, gWPI can be used as a gelatinizing regulator to improve starch properties.

Differences in hydration between high hydrostatic pressure and heat gelatinization of rice starch

The water distribution of high hydrostatic pressure-gelatinized rice starch (HHGS) and heat-gelatinized rice starch (HGS) were investigated under various DGs from 20 % to 100 %, and the effect of hydration on the packing of liquid-crystalline polymer, helix-coil transition, ordered structure change and thermal properties were illustrated. The T2 values at DG25%, the decreased characteristic dimensions of the lamellar structure, the increase of short chains, and the disappeared Maltese cross at DG50% for gelatinized rice starch indicated that the rice starch completed its hydration, which led to the entry of sufficient water to collapse of the crystalline lamellae and ordered structure. LF-NMR results showed that as DG increased, water molecules progressively entered into the tighter structure inside HHGS, and the T2 value decreased and reached a minimum (0.086 ms) at DG75%, while the T2 peak of HGS reached that position at DG25%. Therefore, the collapse of crystalline lamellae, the swelling of granules and the leaching of amylose of HHGS were limited, so the granules were more dispersed. The initial gelatinization temperature (To) and the wide flat DSC peak of HHGS were basically maintained as DG increased. However, the peak of HGS shifted toward higher temperatures and became sharpened and narrowed.

Influence of different hydrocolloids on the pasting, rheological, and morphological characteristics of heat gelatinized cassava starch

Heat-gelatinized starch (HGS), which is prepared via heat treatment, enhances viscosity and provides suitable thickening properties, which improve water retention in products. This study aimed to investigate the potential of blending gelatinized starch with edible hydrocolloids (guar gum, carrageenan (C), locust bean gum, konjac powder, and sodium alginate) to assess their effect on the stabilization of starch gelatinization and reduction of retrogradation. Optical microscopic observations revealed the disrupted structures of gelatinized starch after heat treatments, along with diminished or absent birefringence. Adding C to the gelatinized starch reduced its peak viscosity, breakdown and setback value. For the rheological analysis, heat gelatinization and hydrocolloid addition contributed to the increased elasticity and viscosity of samples. Gelatinization and hydrocolloid addition emerged as effective strategies for improving starch quality. Although it still warrants further exploration, the introduced approach holds potential for applications in the development of convenience and canned food products.

Effects of glutathione on the physicochemical properties of high hydrostatically pressure gelatinized maize starch

This research prepared gelatinized waxy maize starch (WMS), low-amylose maize starch (LAS), and high-amylose maize starch (HAS) with different glutathione (GSH) content (5, 10, and 15 %) using high hydrostatic pressure (HHP) at 600 MPa. Scanning electron microscopy (SEM) revealed damaged morphology of WMS and complete swelled granules of LAS and HAS with different degree of gelatinization (DG) values, 92.86, 59.36, and 17.45 %, respectively. Fourier transform infrared spectroscopy (IR spectra), laser confocal micro-Raman (LCM-Raman) spectroscopy, and X-ray diffraction (XRD) results suggested that the crystallinity content of gelatinized WMS and HAS with addition of GSH was higher than that of LAS, and the gelatinized LAS and HAS were mainly of C type and V type, respectively. The resistant starch of LAS (25.15 %) and HAS (34.76 %) increased with GSH addition. The crosslinking between GSH and amylose/amylopectin caused changes in physicochemical properties. This study will provided theoretical basis for GSH usage in food industry.

Research on the quantitative relationship of the viscosity reduction effect of large-ring cyclodextrin on potato starch during gelatinization process and mechanism analysis

Starch is extensively used across various fields due to its renewable properties and cost-effectiveness. Nonetheless, the high viscosity that arises from gelatinization poses challenges in the industrial usage of starch at high concentrations. Thus, it's crucial to explore techniques to lower the viscosity during gelatinization. In this study, large-ring cyclodextrins (LR-CDs) were synthesized from potato starch (PS) by using 4-α-glucanotransferase and then added to PS to alleviate the increased viscosity during gelatinization. The results from rapid viscosity analyzer (RVA) demonstrated that the inclusion of 5 % (w/w) LR-CDs markedly reduced the peak viscosity (PV) and final viscosity (FV) of PS by 49.85 % and 28.17 %. In addition, there was a quantitative relationship between PV and LR-CDs. The equation was fitted as y = 2530.73×e-x/2.48+1832.79, which provided a basis for the regulation of PS viscosity. The mechanism of LR-CDs reducing the viscosity of PS was also studied. The results showed that the addition of LR-CDs inhibited the gelatinization of PS by enhancing orderliness and limiting water absorption, resulting in a decrease in viscosity. This study provides a novel method for reducing the viscosity of starch, which is helpful for increasing its concentration and reducing energy consumption in industrial applications.

Advances in Biodegradable Food Packaging Using Wheat-Based Materials: Fabrications and Innovations, Applications, Potentials, and Challenges

This article explores the advancements in biodegradable food packaging materials derived from wheat. Wheat, a predominant global cereal crop, offers a sustainable alternative to conventional single-use plastics through its starch, gluten, and fiber components. This study highlights the fabrication processes of wheat-based materials, including solvent casting and extrusion, and their applications in enhancing the shelf life and quality of packaged foods. Recent innovations demonstrate effectiveness in maintaining food quality, controlling moisture content, and providing microbiological protection. Despite the promising potential, challenges such as moisture content and interfacial adhesion in composites remain. This review concludes with an emphasis on the environmental benefits and future trends in wheat-based packaging materials.

Recent advances in the impact of gelatinization degree on starch: Structure, properties and applications

During home cooking or industrial food processing operations, starch granules usually undergo a process known as gelatinization. The starch gelatinization degree (DG) influences the structural organization and properties of starch, which in turn alters the physicochemical, organoleptic, and gastrointestinal properties of starchy foods. This review summarizes methods for measuring DG, as well as the impact of DG on the starch structure, properties, and applications. Enzymatic digestion, iodine colorimetry, and differential scanning calorimetry are the most common methods for evaluating the DG. As the DG increases, the structural organization of the molecules within starch granules is progressively disrupted, the particle size of the granules is altered due to swelling and then disruption, the crystallinity is decreased, the molecular weight is reduced, and the starch-lipid complexes are formed. The impact of DG on the starch structure and properties depends on the processing method, operating conditions, and starch source. The starch DG affects the quality of many foods, including baked goods, fried foods, alcoholic beverages, emulsified foods, and edible inks. Thus, a better understanding of the changes in starch structure and function caused by gelatinization could facilitate the development of foods with novel or improved properties.

Changes in overall digital structure, starch properties and moisture distribution reveal how the hardness of wheat noodles evolves under different cooking status

To elucidate the relationship between the structural evolution of starch within noodles during cooking and the hardness, the panoramic and local microstructure of cooked noodles were quantitatively analyzed, and the structure of starch in noodles were measured. We found that in the case of starch within cooked noodles with a high degree of swelling, the quantitative analysis of each ring was sufficient to represent the structural differences. Changes occurring in starch inside noodles during cooking were not homogeneous. The structural modifications of starch in the outer ring were greater than in the inner ring along with the extension of cooking time. The main reason responsible for the high hardness was attributed to low swelling degree and high short-range order of starch in the center. Water migration from the periphery to the center of the noodles, which was closely related to the fine structure of amylopectin, determined the state of central starch. Wheat starch with more large amylopectin molecules and more long amylopectin chains could enhance the inhibition of water migration and decrease the swelling degree of starch in the center, in order to endow a high hardness to noodles. These results will be useful for the ingredients selection for the production of noodles with desirable quality. In addition, the analysis method established in this work promoted the realization of quantitative comparison of the cooked noodles microstructure, that is an effective tool to clarify the structural basis of macroscopic quality of noodles.

Benefits of Incorporating Lignin into Starch-Based Films: A Brief Review

Polysaccharides are an excellent renewable source for developing food-packing materials. It is expected that these packages can be an efficient barrier against oxygen; can reduce lipid peroxidation, and can retain the natural aroma of a food commodity. Starch has tremendous potential to be explored in the preparation of food packaging; however, due to their high hydrophilic nature, packaging films produced from starch possess poor protective moisture barriers and low mechanical properties. This scenario limits their applications, especially in humid conditions. In contrast, lignin's highly complex aromatic hetero-polymer network of phenylpropane units is known to play a filler role in polysaccharide films. Moreover, lignin can limit the biodegradability of polysaccharides films by a physical barrier, mainly, and by non-productive bindings. The main interactions affecting lignin non-productive bindings are hydrophobic interactions, electrostatic interactions, and hydrogen-bonding interactions, which are dependent on the total phenolic -OH and -COOH content in its chemical structure. In this review, the use of lignin as a reinforcement to improve the biodegradability of starch-based films in wet environments is presented. Moreover, the characteristics of the used lignins, the mechanisms of molecular interaction among these materials, and the sensitive physicochemical parameters for biodegradability detection are related.

Properties of Biocomposites Made of Extruded Apple Pomace and Potato Starch: Mechanical and Physicochemical Properties

This paper presents research results on biocomposites made from a combination of extruded apple pomace (EAP) and potato starch (SP). The aim of this work was to investigate the basic properties of biocomposites obtained from extruded apple pomace reinforced with potato starch. The products were manufactured by hot pressing using a hydraulic press with a mould for producing samples. The prepared biocomposites were subjected to strength tests, surface wettability was determined, and a colour analysis was carried out. A thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and cross-sectioning observed in a scanning electron microscope (SEM) were also performed. The obtained test results showed that the combination of apple pomace (EAP) and starch (SP) enabled the production of compact biocomposite materials. At the same time, it was found that each increase in the share of starch in the mixture for producing biocomposites increased the strength parameters of the obtained materials. With the highest share of starch in the mixture, 40%, and a raw material moisture content of 14%, the material had the best strength parameters and was even characterised by hydrophobic properties. It was also found that materials with a high content of starch are characterised by increased temperature resistance. The analysis of SEM microscopic photos showed well-glued particles of apple pomace, pectin, and gelatinised starch and a smooth external structure of the samples. Research and analyses have shown that apple pomace reinforced only with the addition of starch can be a promising raw material for the production of simple, biodegradable biocomposite materials.

Study on the gelatinization and digestive characteristics of wheat starch and potato starch under low moisture conditions

This study explored the gelatinization and digestive characteristics of wheat and potato starches under low moisture conditions using identical processing parameters. The results revealed that potato starch exhibited greater resistance to digestion than wheat starch, with an enzyme hydrolysis rate 18 % to 30 % lower than wheat starch under the same conditions. The analysis of particle size, swelling power, and low-field NMR demonstrated that potato starch required almost 40 % more moisture for full gelatinization than wheat starch, indicating that low-moisture conditions could not meet the significant water demand of potato starch. Additionally, the DSC analysis showed that potato starch had superior thermal stability, with To of 62.13 °C and ΔH of 16.30 (J/g). Subsequently, the microscopy results showed that the partially gelatinized wheat starch had a rough, porous surface, allowing enzymes for direct access to hydrolysis. In contrast, the potato starch had smoother and less damaged particles without visible pores, enzymes had to degrade it progressively, layer by layer. Furthermore, potato starch still exhibited a lower enzyme hydrolysis rate than wheat starch under the same gelatinization levels. Overall, potato starch is more resistant to hydrolysis and gelatinization in low-moisture environments, making potato starch suitable for low-digestibility products like potato biscuits or chips.

Comprehensive investigation of pressure-induced gelatinization of starches using in situ and ex-situ technical analyses

The pressure-induce gelatinization of pea starch, potato starch and corn starch was investigated by a combination of in situ and ex-situ technical analyses. According to in-situ observation of gelatinization process and the analysis of granular morphology by scanning electronic microscopy (SEM), the pressure that caused potato starch gelatinization was the highest at 600 MPa. This was followed by pea starch, and the pressure that caused the gelatinization of corn starch was the lowest at 400 MPa. In situ Raman spectral analysis revealed the molecular mechanism of starch gelatinization. This indicated that high pressure treatment resulted in the modification of the structure of the double helical polymers and the degree of a double helix of the starch crystalline varied as well. This study dynamically monitors the starch gelatinization process, aiming to better understand the gelatinization mechanism and provide a theoretical basis for the application of pressure in the starch field.

Effect of Sprouted Buckwheat on Glycemic Index and Quality of Reconstituted Rice

This study utilized sprouted buckwheat as the main component and aimed to optimize its combination with other grains to produce reconstituted rice with enhanced taste and a reduced glycemic index (GI). The optimal blend comprised wheat flour, sprouted buckwheat flour, black rice flour, and purple potato flour in a ratio of 34.5:28.8:26.7:10.0. Based on this blend, the reconstituted rice processed through extrusion puffing exhibited a purple-black hue; meanwhile, the instant reconstituted rice, produced through further microwave puffing, displayed a reddish-brown color. both imparted a rich cereal flavor. The starch in both types of rice exhibited a V-shaped structure with lower relative crystallinity. Compared to commercial rice, the reconstituted rice and instant reconstituted rice contained higher levels of flavonoids, polyphenols, and other flavor compounds, along with 1.63-fold and 1.75-fold more proteins, respectively. The GI values of the reconstituted rice and the instant reconstituted rice were 68.86 and 69.47, respectively; thus, they are medium-GI foods that can alleviate the increase in blood glucose levels.

Physicochemical properties of amorphous granular starch (AGS) prepared by non-thermal gelatinization by high hydrostatic pressure (HHP) and spray drying

Corn starch was gelatinized by high hydrostatic pressure (HHP) and spray drying to make amorphous granular starch (AGS), and their physicochemical properties were compared with the conventionally prepared (heat-gelatinized and spray dried) AGS to devise a novel AGS preparation methodology. Pressure-induced (PAGS) and heat-induced AGS (HAGS) maintained their granular shape but lost their birefringence indicating that both methods could prepare AGS. DSC (differential scanning calorimeter) and XRD (X-ray diffraction) analysis confirmed the complete loss of amylopectin double helices and crystallinity of both PAGS and HAGS. However, their swelling power, solubility, RVA pasting properties, acid/shear stability, gel forming ability and textural properties were completely different. PAGS exhibited constrained swelling, suppressed amylose leaching, and reduced viscosity. Notably, HAGS formed a gel without heating, whereas PAGS yielded a viscous paste with water-soluble attributes. Even after reheating, PAGS maintained its granular structure with comparably less swelling and weaker gel strength than HAGS. Consequently, newly developed PAGS exhibited distinctive characteristics compared to the conventional HAGS, such as lower solubility and swelling power, viscosity, textural properties, and high acid and shear stabilities, rendering it a viable option for various applications within the food industry.

Effects of explosion puffing on the native structural organization and oil adsorption properties of starch

The effects of explosion puffing (EP) on the native structural organization (i.e., thermal properties, crystalline structure, short-range order, granule morphology and powder properties) and oil adsorption properties of puffed starch (PS) were investigated. The results showed that EP treatment could decrease the melting enthalpy of starch double helices and increase the V-type crystallinity. The highest V-type crystallinity (24.7 %) was obtained when the puffing pressure was 0.4 MPa and the starch:ethanol:water ratio was 1:2:1 (w/w). By controlling the puffing conditions, EP treatment can alter the morphology, and increase the particle size, flowability and specific surface area of PS. The high amorphous proportion and porous sheet structure of PS resulted in the highest oil adsorption capacity when the starch:ethanol:water ratio was 1:1:1 (w/w). Pearson correlation analysis showed that oil adsorption capacity was significantly and positively correlated with the 1022/995 cm-1 value and V-type crystallinity, but negatively correlated with bulk density and angle of repose. Furthermore, oil retention capacity was strongly dependent on V-type crystallinity. These findings demonstrated that EP is an innovative technology with the potential to enhance the V-type crystallinity and adsorption performance of starch.

Combined effect of heating temperature and content of pectin on the textural properties, rheology, and 3D printability of potato starch gel

Three-dimensional (3D) printing is one of the emerging techniques which fabricates customized foods with desired sensory characteristics. Rheological properties of 3D printing materials are vitally important in printability which govern the flowability and structural stability. Due to its unique gel-forming characteristics, potato starch has been extensively used in myriad food applications, such as 3D printing. However, little attention has been paid to the combined effect of heating temperature and pectin addition on the properties of potato starch gels. Thus, this study investigated the impact of different pectin contents (1, 1.5, and 2 %) on printability and the rheological and textural properties of potato starch gels heated at different temperatures (70, 80, and 90 °C). The gel heating temperature governs pectin-driven modifications in potato starch gels. Pectin addition increased the 3D printability, viscosity, storage modulus, hardness, gumminess, and springiness of starch gel at higher temperatures (80 °C and 90 °C). In contrast, at lower temperatures (70 °C), pectin addition decreased printability, viscosity, storage modulus, hardness, gumminess, and springiness. Therefore, the gel heating temperature influences the impact of pectin on printability, rheology, and textural properties. Accordingly, the combined effects of pectin and heating temperature should be considered in pectin-based 3D food-printing ink formulations.

The effects of high-pressure treatment on the structure, physicochemical properties and digestive property of starch - A review

High hydrostatic pressure (HHP) is a novel technology used in the food-processing industry. Starch is an important renewable natural resource. The applications of starch are determined by its properties, which in turn are determined by its structure. In this study, the effects of HHP treatment on starch structure (granular structure, crystalline structure, molecular structure, and molecular conformation) and properties (pasting, retrogradation, thermal, digestive, rheological, swelling, solubility, water absorption, and oil absorption properties) are summarised. Additionally, the mechanism of HHP-induced gelatinisation is discussed. First, the strong hydration ability of starch molecules under high pressure facilitates the binding of water molecules to starch molecules via hydrogen bonding. These bound water molecules may block the channels inside the starch granules, leading to the formation of a sealed space. Finally, the granules disintegrate because of the intra/extra pressure difference. This study provides a reference for the application of HHP to starch processing and modification.

Insight into the Effects of Drying Methods on Lanzhou Lily Rehydration

This study investigated the effects of drying methods (hot air drying (HAD), microwave vacuum drying (MVD), and vacuum freeze drying (VFD)) on the rehydration performance (RP) of dried Lanzhou lily scales (LLS). Rehydration rate and water migration showed that MVD had the best RP, followed by VFD, while HAD had the worst. The results of additional morphology observation using scanning electron microscopy (SEM) and micro X-ray computed tomography (CT) imaging showed that both MVD and VFD created more channels in more porous structures, which facilitated their better RP than that by HAD. The results also revealed the spatial structure diversity (including pores, channels size, and internal network) of each dried Lanzhou lily scale group. In addition, studies analyzed how drying techniques affected the physiochemical properties of lily starch, including its water solubility, pasting profiles, and starch particle morphology. The findings indicated that when MVD was in operation, partial gelatinization in lily starch was brought about by thermal effects, allowing MVDS crystals to change from B-type to V-type and causing MVDS to have better water absorption ability. Consequently, despite the fact that MVD's desiccated lilies have a lower porous structure and thinner channels than VFD's, MVD has a higher RP than VFD.

Binary Hydrogels: Induction Methods and Recent Application Progress as Food Matrices for Bioactive Compounds Delivery-A Bibliometric Review

Food hydrogels are biopolymeric materials made from food-grade biopolymers with gelling properties (proteins and polysaccharides) and a 3D network capable of incorporating large amounts of water. They have sparked considerable interest because of their potential and broad application range in the biomedical and pharmaceutical sectors. However, hydrogel research in the field of food science is still limited. This knowledge gap provides numerous opportunities for implementing their unique properties, such as high water-holding capacity, moderated texture, compatibility with other substances, cell biocompatibility, biodegradability, and high resemblance to living tissues, for the development of novel, functional food matrices. For that reason, this article includes a bibliometric analysis characterizing research trends in food protein-polysaccharide hydrogels (over the last ten years). Additionally, it characterizes the most recent developments in hydrogel induction methods and the most recent application progress of hydrogels as food matrices as carriers for the targeted delivery of bioactive compounds. Finally, this article provides a future perspective on the need to evaluate the feasibility of using plant-based proteins and polysaccharides to develop food matrices that protect nutrients, including bioactive substances, throughout processing, storage, and digestion until they reach the specific targeted area of the digestive system.

Physical, Chemical and Biochemical Modification Approaches of Potato (Peel) Constituents for Bio-Based Food Packaging Concepts: A Review

Potatoes are grown in large quantities and are mainly used as food or animal feed. Potato processing generates a large amount of side streams, which are currently low value by-products of the potato processing industry. The utilization of the potato peel side stream and other potato residues is also becoming increasingly important from a sustainability point of view. Individual constituents of potato peel or complete potato tubers can for instance be used for application in other products such as bio-based food packaging. Prior using constituents for specific applications, their properties and characteristics need to be known and understood. This article extensively reviews the scientific literature about physical, chemical, and biochemical modification of potato constituents. Besides short explanations about the modification techniques, extensive summaries of the results from scientific articles are outlined focusing on the main constituents of potatoes, namely potato starch and potato protein. The effects of the different modification techniques are qualitatively interpreted in tables to obtain a condensed overview about the influence of different modification techniques on the potato constituents. Overall, this article provides an up-to-date and comprehensive overview of the possibilities and implications of modifying potato components for potential further valorization in, e.g., bio-based food packaging.

Research progress in fluid and semifluid microwave heating technology in food processing

Microwave is a form of electromagnetic radiation that has high penetration and heating efficiency in food processing. Uneven heating is the main problem of microwave processing, especially in solid foods. Fluid and semifluid media, which are good carriers in microwave processing, have uniform dielectric properties and good material fluidity. Herein, we review the development, application prospects, and limitations of microwave in fluid and semifluid food processing and the research progress in microwave heating with steam as carrier. The mixture of generated steam and tiny micro droplets from food material under the action of microwave can absorb microwave and transfer heat evenly, which effectively improves the uniformity of microwave heating. Due to the relatively uniform dielectric properties and consistent texture of fluid and semifluid food materials, uneven heating phenomenon during their microwave processing can be significantly inhibited. Based on the development of microwave heating technology and equipment design, the microbial inactivation and enzyme inhibition in fluid and semifluid food were improved and food product with better retention of nutrients and sensory profile were produced. Also, microwave radiation can be used to prepare the printing material or process the printed product for 3D food printing, which enhances the added value of 3D printed products and the personalization of food manufacturing. In future research, intelligent control technology can be applied in the microwave processing of fluid and semifluid food materials for various applications. Therefore, the processing conditions can be adjusted automatically.

Biodegradation behavior and digestive properties of starch-based film for food packaging - a review

Non-degradable plastic places a serious burden on the environment, so consumers and researchers are working to develop biodegradable, safe, and sustainable food packaging materials. The starch-based film has become emerging material for food packaging. Not only does it shows excellent physicochemical properties, but also provides the desired degradation characteristics after use or the digestive properties after consumption, thus needing to comprehensively evaluate the quality of starch-based food packaging materials. This review summarizes the degradation behavior of the starch-based film in different degradation environments, and compares the suitability of degradation environments. Besides, the physicochemical properties of the composite or blend film during the degradation process were further discussed. The factors affecting the digestibility of starch-based edible film were reviewed and analyzed. Finally, the application and the future trend of the biodegradable starch-based film in the food packaging field were proposed. Future studies should combine and evaluate the physical properties and biodegradability of the composite/blend film, to develop food packaging materials with good characteristics and biodegradability.

Nonthermal physical modification of starch: An overview of recent research into structure and property alterations

To tailor the properties and enhance the applicability of starch, various ways of starch modification have been practiced. Among them, physical modification methods (micronization, nonthermal plasma, high-pressure, ultrasonication, pulsed electric field, and γ-irradiation) are highly potential for starch modification considering its safety, environmentally friendliness, and cost-effectiveness, without generating chemical wastes. Thus, this article provides an overview of the recent advances in nonthermal physical modification of starch and summarizes the resulting changes in the multi-level structures and physicochemical properties. While the effect of these techniques highly depends on starch type and treatment condition, they generally lead to the destruction of starch granules, the degradation of molecules, decreases in crystallinity, gelatinization temperatures, and viscosity, increases in solubility and swelling power, and an increase or decrease in digestibility, to different extents. The advantages and shortcomings of these techniques in starch processing are compared, and the knowledge gap in this area is commented on.

Research progress on polysaccharide/protein hydrogels: Preparation method, functional property and application as delivery systems for bioactive ingredients

Some bioactive ingredients in foods are unstable and easily degraded during processing, storage, transportation and digestion. To enhance the stability and bioavailability, some food hydrogels have been developed to encapsulate these unstable compounds. In this paper, the preparation methods, formation mechanisms, physicochemical and functional properties of some protein hydrogels, polysaccharide hydrogels and protein-polysaccharide composite hydrogels were comprehensively summarized. Since the hydrogels have the ability to control the release and enhance the bioavailability of bioactive ingredients, the encapsulation and release mechanisms of polyphenols, flavonoids, carotenoids, vitamins and probiotics by hydrogels were further discussed. This review will provide a comprehensive reference for the deep application of polysaccharide/protein hydrogels in food industry.

Physicochemical and Structural Characterization of Potato Starch with Different Degrees of Gelatinization

Starch gelatinization has been widely studied previously, but there is still a lack of systematical research on the relationship between the degree of starch gelatinization (DSG) and its physicochemical and structural properties. In this study, potato starch samples with DSG ranging from 39.41% to 90.56% were obtained by hydrothermal treatment. The thermal, rheological, and structural properties, as well as the water-binding capacity of samples were investigated. A starch solution with a DSG of 39.41% was partially sedimented at room temperature, while starch with a DSG of 56.11% can form a stable paste with a fine shear-thinning property, as well as samples with a DSG larger than 56.11%. The endothermic enthalpy, gelatinization range, and short-range ordered structure of starch were negatively correlated with DSG, whereas onset gelatinization temperature, apparent viscosity, and water-binding capacity were positively correlated. The viscoelasticity of starch gels was negatively correlated with the DSG after full gelatinization (DSG > 39.41%). Starch granules gradually lose their typical shape and less birefringence can be observed with increasing DSG. Hydrothermal treatment has a more significant effect on the amount of exposed hydroxyl groups than the ordered and amorphous structures of partially gelatinized starch. This study built linear correlations between starch physicochemical properties and the DSG and provided comprehensive insight into the characteristics of partially gelatinized potato 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.