The impact of germination on the characteristics of brown rice flour and starch

Effect of illite pretreatment on germinated Brown rice with Special Reference to amino acids, antioxidants, texture, and mineral elements

The pretreatment process of various foods has been reported to improve their nutritional properties. The soaking of brown rice improves the texture and nutrients, which are crucial for cooking and maintaining its high functional value. Illite, a clay mineral, has recently been discovered to improve the nutritional value of seeds. Based on these findings, we soaked brown rice with different concentrations of illite solution for different durations and allowed the germination to perform analyses. Soaking the brown rice for 6 h with a germination period of 48 h was determined to be the optimal condition because of its higher sprout length. In addition, this optimal condition had improved textural characteristics such as reduced hardness, gumminess, chewiness, and cohesiveness, and it also had increased adhesiveness and stabilized resilience and springiness. The treatment solutions were free from heavy metal contaminants, whereas the mineral contents such as K, Ca, Fe, Mg, and Na were significantly increased with the increase in illite concentration. Moreover, our results showed that illite treatment could preserve the color appearance and seed germination. The ratio of essential amino acids to non-essential amino acids and antioxidants (phenolic contentγ-oryzanol, and flavonoid) of germinated brown rice was considerably increased with illite treatment. In germinated brown rice, an increase in DPPH and superoxide dismutase levels, a slight decrease in flavonoids, and no difference in polyphenol content were observed. These findings suggest that pre-soaking brown rice seeds with the appropriate concentration of illite could enhance their nutritional properties, which might attract consumers' interest to include this in their daily diet.

Characteristics of amylose-lipid complex prepared from pullulanase-treated rice and wheat flour

This study aimed to evaluate the properties of amylose-lipid complexes in rice and wheat flours utilizing pullulanase as a debranching enzyme. Rice and flour were both treated with pullulanase before being combined with free fatty acids to form compounds denoted as RPF (rice-pullulanase-fatty acid) and FPF (flour-pullulanase-fatty acid), respectively. Our results showed that RPF and FPF had higher complex index and lower hydrolysis values than enzyme-untreated amylose-lipid complexes. Furthermore, RPF and FPF demonstrated lower swelling power and higher water solubility values, indicating changes in the physical properties of the starches. In vivo studies showed that RPF and FPF caused a smaller increase in blood glucose levels than untreated rice and flour, highlighting their potential use as functional food ingredients. These findings provide valuable information for the development of novel rice-and wheat-based foods with improved nutritional and physiological properties.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01411-0.

Pulsed light treatment enhances starch hydrolysis and improves starch physicochemical properties of germinated brown rice

BACKGROUND

Recently, germinated brown rice (GBR) has gained substantial attention as a functional food because of its nutritional attributes. Notably, pulsed light technology (PLT) has emerged as a promising tool for enhancing rice germination and, consequently, has improved the nutritional and functional qualities of GBR-derived products. However, further research is required to comprehensively understand the impact of PLT on GBR physicochemical properties. The present study aimed to investigate the stimulating effects of PLT on starch hydrolysis, starch structure and functional properties of GBR.

RESULTS

The PLT substantially boosted α-amylase activity during brown rice germination, leading to a 10.9% reduction in total starch content and a 17.3% increase in reducing sugar content, accompanied by elevated free water levels. Structural analysis indicated no changes in starch crystalline types, whereas gelatinization temperature slightly increased. Pasting properties exhibited a significant drop in peak viscosity. Scanning electron microscopy showed surface erosion of starch granules with microstructural changes. Furthermore, correlation analysis established positive links between α-amylase activity, reducing sugar accumulation, starch structure and functional properties in GBR.

CONCLUSION

The present study demonstrates that PLT enhanced the physicochemical properties of GBR starch, significantly improving the stability of GBR products, thereby contributing to expanded applicability of rice starch in the food industry. © 2023 Society of Chemical Industry.

New horizon to the world of gut microbiome: seeds germination

The second brain of humans has been known as the microbiome. The microbiome is a dynamic network composed of commensal bacteria, archaea, viruses, and fungi colonized in the human gastrointestinal tract. They play a vital role in human health by metabolizing components, maturation of the immune system, and taking part in the treatment of various diseases. Two important factors that can affect the gut microbiome's composition and/or function are the food matrix and methods of food processing. Based on scientific research, the consumption of whole grains can make positive changes in the gut microbiota. Seeds contain different microbiota-accessible substrates that can resist digestion in the upper gastrointestinal tract. Seed germination is one of the simplest and newest food processing approaches to improve seeds' bioavailability and overall nutritional value. During germination, the dormant hydrolytic seed's enzymes have been activated and then metabolize the macromolecules. The quality and quantity of bioactive compounds like prebiotics, fiber, phenolic compounds (PC), total free amino acids, and γ-aminobutyric acid (GABA) can increase even up to 4-10 folds in some cases. These components stimulate the survival and growth of healthful bacteria like probiotics and boost their activity. This effect depends on several parameters, e.g., germination environmental conditions. This review aims to provide up-to-date and latest research about promoting bioactive components during seed germination and investigating their impacts on gut microbiota to understand the possible direct and indirect effects of seed germination on the microbiome and human health.

Impact of germination on the techno-functional properties, nutritional composition, and health-promoting compounds of brown rice and its products: A review

Rice is a popular grain and forms part of the daily diet of people throughout the world. However, the consumption of rice and its products is sometimes limited by its high glycemic index due to its high starch content, low protein content and quality, and low bioavailability of minerals due to the presence of anti-nutritional factors. This has partly stimulated research interest in recent times toward the use of bioprocessing techniques such as germination as cheap and natural means to improve the nutritional quality, digestibility, and health properties of cereals, including rice, to partially achieve nutrition and food security in the developing regions of the world. This review highlights the impact of germination on the nutritional quality, health-promoting properties, and techno-functional characteristics of germinated brown rice grains and their products. The review demonstrated that germinated rice grains and their products have improved nutritional quality and digestibility, modified functional properties, and showed antioxidant, anti-inflammatory, anti-diabetic, anti-obesity, anti-cancer, and anti-cardiovascular activities. Germination appears to be a suitable bioprocessing method to improve the nutritional quality and bioactive constituents and modify the techno-functional properties of rice grains for diverse food applications and improved global nutrition and food safety.

Health-promoting germinated rice and value-added foods: a comprehensive and systematic review of germination effects on brown rice

Over the last 30 years, thousands of articles have appeared examining the effects of soaking and germinating brown rice (BR). Variable germination conditions and methods have been employed to measure different health-beneficial parameters in a diverse germplasm of BR. Research results may therefore appear inconsistent with occasional anomalies, and it may be difficult to reach consensus concerning expected trends. Herein, we amassed a comprehensive review on germinated brown rice (GBR), attempting to codify 133 peer-reviewed articles regarding the effects on 164 chemical parameters related to health and nutrition in BR and in value-added food products. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-2020) approach was used to direct the flow of the literature search. A pair-wise comparison t-test was performed to deliver an overall approach indicating when a given compound has been found to significantly increase or decrease through germination, which was grouped into GABA and polyamines, γ-Oryzanol and phytosterols, phenolic compounds, vitamins, proteins and amino acids, starchy carbohydrates, free sugars, lipids, minerals and phytic acid. This resource will stimulate interest in germinating rice and optimistically help increase both production and consumption of highly nutritious, health-beneficial rice with pigmented bran.

Improving γ-Oryzanol and γ-Aminobutyric Acid Contents in Rice Beverage Amazake Produced with Brown, Milled and Germinated Rices

Rice is an important source of γ-oryzanol (GO) and γ-aminobutyric acid (GABA), which are bioactive compounds that may benefit blood lipid and pressure control. Both GO and GABA can be improved by germination and fermentation. Fermentation with A. oryzae produces Koji, a rice-based starter for Amazake, a naturally sweet beverage. Germinated rice (brown and milled rice), were tested to improve those bioactive compounds during the fermentation process. The resulting Koji was optimised to GO and GABA through a response surface methodology; α-amylase activity and starch content were also assessed. The different rice matrix resulting from the germination largely impacted the biosynthesis of GABA, α-amylase and starch contents. Amazake, obtained by germinated rice, has increased GO and GABA contents when compared to the one obtained from milled rice (from a non-detectable value to 27.65 ± 0.23 mg/100 g for GO and from 163.95 ± 24.7 to 271.53 ± 5.7 mg/100 g for GABA). A panel of 136 Portuguese consumers tasted the beverage in a blind overall tasting test followed by an informed test, using 9-point scales. The consumer scores had a mean value of 4.67 ± 1.9 and 4.9 ± 1.8, meaning that cultural differences may play an important role with regard to liking and accepting Amazake.

Dough Rheological Behavior and Bread Quality as Affected by Addition of Soybean Flour in a Germinated Form

This study analyzes the possibility of using soybeans as an addition to the main ingredients used to make bread, with the aim of improving its quality characteristics. To maximize the nutritional profile of soybeans they were subjected to the germination and lyophilization process before being used in bread making. The addition levels of 5%, 10%, 15%, and 20% germinated soybean flour (GSF) on dough rheology and bread quality were used. From the rheology point of view, the GSF addition had the effect of decreasing the values of the creep and recovery parameters: J_Co, J_Cm, μ_Co, J_max, J_Ro, J_Rm, and J_r. At the same time, the rheological parameters λ_C and λ_R increased. The GSF addition did not affect dough homogeneity as may be seen from EFLM analysis. Regarding the quality of the bread, it may be concluded that a maximum of 15% GSF addition in wheat flour had a desirable effect on loaf volume, porosity, elasticity, and sensory properties of the bread. The bread samples with GSF additions showed a higher brightness and a less pronounced red and yellow tint. When the percentage of GSF in wheat flour increased, the value of the firmness parameter increased and the value of the gumminess, cohesiveness, and resilience parameters decreased. The addition of GSF had a desirable influence on the crumb structure of the bread samples. Thus, taking into account the results of the determinations outlined above, it can be stated that GSF addition in wheat flour leads to bread samples with good quality characteristics.

Effect of static magnetic field treatment on the germination of brown rice: Changes in α-amylase activity and structural and functional properties in starch

The study aimed to explore the stimulating effect of static magnetic field (SMF) treatment on germinated brown rice (GBR) by monitoring changes in α-amylase activity and structural and functional properties of starch. Brown rice was exposed to SMF (10 mT, 60 min, 25 °C) and then germinated for 0 h -72 h at 30 °C. Compared with the control, SMF treatment improved α-amylase activity (15.2%), leading to the hydrolysis of starch into reducing sugar (8.2%) and increasing the germination rate (9.7% -158.8%), shoot length (9.1% -87.3%), root length (19.2% -110.0%), and fresh weight (0.9% -16.5%). In view of the properties of starch, SMF treatment also altered the surface microstructure, induced partial losses of birefringence, exerted no significant effect on the crystalline type, slightly increased the gelatinization temperatures, and significantly decreased the peak viscosity. This study suggested that SMF could serve as a prospective technique for GBR products processing.

Whole grain rice: Updated understanding of starch digestibility and the regulation of glucose and lipid metabolism

Nowadays, resulting from disordered glucose and lipid metabolism, metabolic diseases (e.g., hyperglycemia, type 2 diabetes, and obesity) are among the most serious health issues facing humans worldwide. Increasing evidence has confirmed that dietary intervention (with healthy foods) is effective at regulating the metabolic syndrome. Whole grain rice (WGR) rich in dietary fiber and many bioactive compounds (e.g., γ-amino butyric acid, γ-oryzanol, and polyphenols) can not only inhibit starch digestion and prevent rapid increase in the blood glucose level, but also reduce oxidative stress and damage to the liver, thereby regulating glucose and lipid metabolism. The rate of starch digestion is directly related to the blood glucose level in the organism after WGR intake. Therefore, the effects of different factors (e.g., additives, cooking, germination, and physical treatments) on WGR starch digestibility are examined in this review. In addition, the mechanisms from human and animal experiments regarding the correlation between the intake of WGR or its products and the lowered blood glucose and lipid levels and the reduced incidence of diabetes and obesity are discussed. Moreover, information on developing WGR products with the health benefits is provided.

Effects of Variety, Early Harvest and Germination on Pasting Properties and Cooked Grain Texture of Brown Rice

Brown rice is superior to white rice in nutritional value and in prevention of chronic diseases. However, it is not the preference of consumers and the relative consumption of brown rice is limited due to a number of factors including chewiness and perceived hard texture after cooking. While both early harvested brown rice and germinated brown rice have been shown to contain superior nutritional components, there is limited knowledge on textural properties of these types of brown rice relative to standard brown rice, and how varieties may affect such properties. Thus, the present study examined the effect of variety, early harvest and germination on those properties of 8 rice varieties with contrasting amylose content and known texture in terms of milled rice. Early harvest and germination decreased pasting viscosities and cooked grain hardness. However, their effect on the characteristics of flour and whole grains differed, in which germination had greater effect on pasting properties, while early harvest on texture of cooked grains. Softer texture of brown rice, about 32% lower could be achieved by germination, and 46% by harvesting early. There was a good relationship between pasting characteristics particularly setback and hardness among different varieties in brown rice, germinated brown rice and also in early harvest brown rice. This is the first time the comparison of texture between the 3 brown rice types has been reported. The results also provide new options for selection of desired characteristics for food processing and brown rice consumption. This article is protected by copyright. All rights reserved.

Bread preparation by partial replacement of wheat by germinated sorghum

Published literature shows significant impact of sorghum type and flour on end-product quality, while demonstrating paucity in the studied varieties with respect to processing aspects (such as bread making) despite of enormous accessions available worldwide. Limited studies have reported usage of germinated flour for the above said purpose. The present study thus aimed at mitigating these gaps by utilizing results of sorghum (HJ-513) germination (Day 1-5) and flour derived from optimized condition (Day 3 as identified by partial least square analysis) to develop a composite functional bread (partial replacement of wheat). The germination process enhanced the total phenolics compounds (TPC, till day 3), water (14.01%) and oil absorption capacity (25.97%) while reducing the bulk density (760.99-644.69 kg/m³). This demonstrated increased potential of sorghum flour for development of bakery and confectionery products. The process also affected the pasting properties, total flavonoids compounds (TFC) and DPPH (2, 2-diphenyl-1-picrylhydrazyl) significantly (p < 0.05). The bread developed from partial replacement (10% and 20%) of refined wheat flour by sorghum was hard and darker than the control wheat bread. The bread developed at 20% was more dense and porous than the bread developed with 10% replacement. Specific volume of bread at 10% replacement was found higher than at 20% replacement. The study reports effective utilization of germinated sorghum flour for development of composite-functional bread without incorporation of any other additives/improvers. Future research however is warranted in the field to further increase the replacement of wheat flour by germinated sorghum flour to develop gluten free bread.

Effect of heat-moisture treatment of germinated black rice on the physicochemical properties and its utilization by lactic acid bacteria

The heat susceptibility of starch granule structure has been considering as significant limitation of germinated black rice (GBR) using in food processing industry. Therefore, this study aimed to improve the physicochemical and antioxidation property as well as its effect on the probiotics of GBR by heat moisture treatment (HMT). Black rice germinated at 37.5 °C for 12, 24, and 36 h were studied. Ultrastructural image of each sample was visualized through scanning electron microscope. The results illustrated 24 h-GBR retain its former shape with rough surface. Subsequently, 24 h-GBR was structurally modified by HMT with moisture levels of 20% and 25% for 1 and 2 h. The results showed that pasting properties of HMT-treated GBR were improved. This was particularly on, GBR using HMT condition of 25% moisture for 2 h decrease in breakdown viscosity was shown. Moreover, phenolic content of HMT-treated GBR was higher than those of GBR. Besides, the number of the Lactobacillus paracasei TOKAI 13 was increased in GBR and HMT-treated GBR with counts of 10.08 ± 0.83 Log CFU/ml and 9.31 ± 0.33 Log CFU/ml, respectively, with significant increases in antioxidant property. Therefore, the HMT-GBR could be utilized as an alternative functional ingredient in food processing products.

Sprouting Time Affects Sorghum (Sorghum bicolor [L.] Moench) Functionality and Bread-Baking Performance

Despite being considered a climate-resilient crop, sorghum is still underutilized in food processing because of the limited starch and protein functionality. For this reason, the objective of this study was to investigate the effect of sprouting time on sorghum functional properties and the possibility to exploit sprouted sorghum in bread making. In this context, red sorghum was sprouted for 24, 36, 48, 72, and 96 h at 27 °C. Sprouting time did not strongly affect the sorghum composition in terms of total starch, fiber, and protein contents. On the other hand, the developed proteolytic activity had a positive effect on oil-absorption capacity, pasting, and gelation properties. Conversely, the increased α-amylase activity in sprouted samples (≥36 h) altered starch functionality. As regards sorghum-enriched bread, the blends containing 48 h-sprouted sorghum showed high specific volume and low crumb firmness. In addition, enrichment in sprouted sorghum increased both the in vitro protein digestibility and the slowly digestible starch fraction of bread. Overall, this study showed that 48 h-sprouted sorghum enhanced the bread-making performance of wheat-based products.

Increased γ-Aminobutyric Acid Content of Germinated Brown Rice Produced in Membrane Reactor

RESEARCH BACKGROUND

Rice germination is a natural approach to enhance the physical and functional properties of brown rice. Thus, the aim of this study is to investigate the influence of different germination methods on functional properties of germinated brown rice and evaluate the process feasibility.

EXPERIMENTAL APPROACH

Brown rice of IPB 3S variety was germinated with three different methods: (i) complete soaking without water replacement, (ii) complete soaking with water replacement every six hours, and (iii) complete soaking with continuous washing in the developed membrane-facilitated soaking reactor.

RESULTS AND CONCLUSIONS

The application of the membrane reactor for producing germinated brown rice maintained the pH of the soaking solution relatively constant (i.e. 6.8-7.0). This indicated the circumvention of natural fermentation during brown rice germination. Moreover, the mass fraction of γ-aminobutyric acid in germinated brown rice produced in the membrane reactor was about 4.5-fold higher (169.2 mg/100 mg) than in ungerminated brown rice (36.82 mg/100 mg), and also higher than that of the other two soaking methods. The γ-oryzanol mass fractions and the antioxidant capacity expressed as ascorbic acid equivalents of germinated brown rice obtained with the three soaking methods varied from 32 to 38 mg/100 mg and 18 to 28 mg/100 g, respectively. Within this study, germination could also slightly reduce the transition temperatures of germinated brown rice starch gelatinization (t o=73-74 °C, t p=76-77 °C and t c=~80 °C, where t o, t p and t c are onset, peak and conclusion (final) temperatures). In conclusion, the production of germinated brown rice in the membrane reactor could enhance its γ-aminobutyric acid mass fraction and reduce wastewater production and is therefore considered more feasible.

NOVELTY AND SCIENTIFIC CONTRIBUTION

This study demonstrates the feasibility of germinated brown rice production using a membrane-facilitated soaking reactor with enhancement of bioactive compound content, especially γ-aminobutyric acid, and minimised wastewater production.

Changes in physicochemical, nutritional characteristics and ATR-FTIR molecular interactions of cereal grains during germination

The cereal grains such as wheat, barley, sorghum, millets were evaluated before and after germination (24 h, 48 h and 72 h) and compared for their proximate composition, antioxidant activity, total phenolic content, total flavonoid content, pasting properties, in vitro starch digestibility and FTIR spectroscopy. Germination inversely affected the protein, fat, and ash content of different cereal grains. The germinated flours have less water content and higher oil absorption capacities along with reduced starch content. The contents of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) in the ungerminated cereal flours ranged from 20.7 to 32.1%, 26.9 to 38.0% and 6.2 to 17.6% respectively but after germination of 72 h, the RDS content increased from 26.5 to 36.2% while SDS and RS content decreased from 26.1% (sorghum) to 16% (barley) and 14.7% (barley) to 4.6% (wheat) respectively. The drought-tolerant crops (sorghum, millets and barley) are potential sources of antioxidants and phenolic content and yielded lower hydrolysis index and estimated glycaemic index upon germination. The highest section of antiparallal β-sheet, α-helix and β-turns were found in wheat flour followed by sorghum flour and their proportion decreased with continuous germination. The continuous reduction of viscosity was evaluated with the progress in germination. Overall, germination is a way to get health-promoting compounds from less utilizing cereal such as millets, sorghum and barley and enhance their uses to nourish the huge population with the aim to fulfill their nutritional requirements.

Influence of germination on physicochemical properties of flours from brown rice, oat, sorghum, and millet

The changes in physiochemical properties of flours obtained from the four selected grains after germination were investigated. After germination, the sprout length of sorghum and millet was substantially larger than that of brown rice and oat. Germination led to a decrease in the apparent amylose content and swelling factor of flours. Gelatinization onset and peak temperatures increased after germination, while a slight decrease was found in conclusion temperature. Compared to the raw flours, the germinated flours derived from brown rice, sorghum, and millet had lower gelatinization enthalpy, whereas the germinated oat flour showed higher gelatinization enthalpy. Germination resulted in significant decrease in pasting parameters of the four flours. Amylose leaching of sorghum and millet flours increased after germination, while the brown rice and oat flours showed a significant decrease in amylose leaching. Results suggest that germination effectively altered the physicochemical properties of grain flours, which can be utilized as functional ingredient in the preparation of grain-based products.

Metabolomic Analysis of Germinated Brown Rice at Different Germination Stages

Brown rice (BR) is unpolished rice containing many bioactive compounds in addition to the basic nutrients of the rice grain. Herein, BR was germinated for up to 48 h to prepare germinated brown rice (GBR). The physiological and chemical changes in the GBR during germination were analyzed. GBR samples germinated for 48 h were in the radicle-emergence stage, but root formation was not observed. The change in the GBR metabolite profile during germination was analyzed to determine the effect of germination on the chemical profiles of the GBR samples. Twenty-five metabolites including acidic compounds, amino acids, sugars, lipid metabolites, and secondary metabolites were identified as the components that contributed to the variations in the GBR groups germinated for different time periods. Among the metabolites, the carbohydrates associated with energy production and lipid metabolites changed significantly. Based on the identified metabolites, a metabolomic pathway was proposed. Carbohydrate metabolism, citric acid cycle, and lipid metabolism were the main processes that were affected during germination. Although further studies on the relationship between the metabolite profile and nutritional quality of the GBR are needed, these results are useful for understanding the effect of germination on the physiological and chemical changes in BR.

Effects of germination time and kilning temperature on the malting characteristics, biochemical and structural properties of HomChaiya rice

Effects of germination time (3, 5 and 7 days) and kilning temperature (40, 50 and 60 °C) on the malting characteristics, biochemical properties and structural properties of HomChaiya rice were examined. Malting potential in terms of germination rate and germination capacity increased as the germination period of rice was prolonged. Diastatic potential, hot water extract and malting loss of rice gradually increased with germination time and with kilning temperature; in contrast, malting yield and viscosity of the samples decreased. Germination time significantly increased the α-amylase activity, but β-amylase activities increased when kilned at different temperatures. Total starch decreased and reducing sugar increased in rice with prolonged germination, and furthermore, the kilning temperature significantly influenced these changes. Higher kilning temperature and prolonged germination period increased the protease activity in rice, and consequently, soluble protein and free amino acids also increased. Among the twelve identified amino acids in the HomChaiya rice, aspartic acid, glutamic acid, asparagine, serine, arginine, isoleucine, tyrosine, and phenylalanine increased with germination time and kilning temperature. FTIR results showed that increased germination time and kilning temperature unfolded the carbohydrates, which is consistent with the enzymatic (α- and β-amylase) activities. XRD results also found higher peak intensities for rice when germinated longer and kilned at a higher temperature. The crystallinity of malted rice decreased with germination time. Ultrastructural changes showed that starch granules are more vulnerable to enzymatic attack upon extended germination time and at higher kilning temperatures.

Effects of germination time (3, 5 and 7 days) and kilning temperature (40, 50 and 60 °C) on the malting characteristics, biochemical properties and structural properties of HomChaiya rice were examined.

Changes in starch structures and in vitro digestion characteristics during maize (Zea mays L.) germination

This study analyzed changes in the starch structures and in vitro digestion profiles of a specific maize cultivar, Jike 728 (JK728), in Jilin, China, after 0-5 days of germination. The total starch, amylose, and amylopectin contents decreased significantly during germination. The average molecular weight of the starch compounds also decreased significantly during germination. The proportion of amylopectin with a degree of polymerization (DP) of 13-24 significantly decreased, while the relative abundance of amylopectin with DP values of 6-12, 25-36, and 37-60 significantly increased. The X-ray diffraction (XRD) patterns of all samples were characteristic of A-type starch, and the starch relative crystallinity decreased over time. The proportions of slowly digestible starch and resistant starch decreased significantly, while the proportion of rapidly digestible starch increased significantly during germination. Germination is an easy, inexpensive, and low-carbon processing method. This study indicates that germination is an effective way to control the physical properties and digestibility of starch in maize. The changes observed in the physical properties and digestibility of maize starch after germination provide scientists with a platform to understand starch modification mechanisms that might have potential applications on an industrial scale.

Improvement of germinated brown rice quality with autoclaving treatment

Germinated brown rice (GBR) is a popular functional food containing considerable amounts of beneficial nutrients and bioactive compounds. Here, autoclaving at 115°C for 20 min was employed to process GBR (AGBR) to evaluate the effect of autoclaving on the nutritional and health function of GBR in microstructure, taste value, aroma, as well as the physiological ingredients. The results showed that autoclaving treatment influenced the starch gelatinization and aroma to improve the taste of cooked AGBR. Autoclaving treatment significantly increased the gamma‐aminobutyric acid (GABA) and ferulic acid levels of AGBR (p < .05). In addition, consuming AGBR for 1 month significantly decreased the fasting plasma glucose (FPG), 0.5, 1, and 2 hr postprandial plasma glucose (PPG), triglyceride (TG), total cholesterol (TC), high‐density lipoprotein cholesterol (HDL‐c), and low‐density lipoprotein cholesterol (LDL‐c) in metabolic syndrome (MS) patients (p < .05). Therefore, autoclaving treatment, as a promising processing strategy, may both improve the sensory attributes and the nutrition of GBR.