The use of the rapid visco analyser (RVA) in breeding and selection of cereals

Comparative analysis of malt quality and starch characteristics of three South Korean barley cultivars

In this study, malt was produced in pilot-scale facilities and conditioned using three barley (Hordeum vulgare L.) cultivars in South Korea (Heugho, Hopum, and Kwangmaeg). Quality and starch characteristics were compared. The starch content was considerably reduced in all malts. Coleoptile elongation was higher in Heugho (HHM; 85.7% ± 12.6%) and Hopum (HPM; 83.9% ± 10.7%) than in Kwangmaeg (KMM; 78.1% ± 9.9%) malt. Malt yield ranged from 81.8 to 84.9%, with no significant difference. All samples presented type A crystallinity, and granules showed discoid shapes. After malting, the mono- and di-saccharide contents (not including sucrose) were increased. The fermentable sugar level was the highest in HHM, whereas non-fermentable sugar was the highest in KMM. These results suggest that HPM enables efficient scarification based on the rapid degradation of starch, while Heugho barley and HHM have a high potential for beer and malt production, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01419-6.

Effect of extrusion on the formation, structure and properties of yam starch-gallic acid complexes

This paper investigated the effects of twin-screw extrusion treatment on the formation, structure and properties of yam starch-gallic acid complexes. Yam starch and gallic acid were extruded. The microstructure, gelatinization characteristics, and rheological properties of the samples were determined. The microstructure of extruded yam starch-gallic acid complexes presented a rough granular morphology, low swelling, and high solubility. The X-ray diffraction analysis showed that the extruded yam starch-gallic acid complexes exhibited A + V-type crystalline structure. Fourier transform infrared spectroscopy results showed that the extrusion treatment could destroy the internal orderly structure of yam starch, and the addition of gallic acid could further reduce its molecular orderliness. Differential scanning calorimetry analysis showed a decrease in the enthalpy of gelatinization of the sample. Dynamic rheological analysis showed that the storage modulus and loss modulus of the extruded yam starch-gallic acid complexes were significantly reduced, exhibiting a weak gel system. The results of viscosity showed that extrusion synergistic gallic acid reduced the peak viscosity and setback value of starch. In addition, extrusion treatment had an inhibitory effect on the digestibility of yam starch, and enhanced the interaction of gallic acid with yam starch or hydrolytic enzymes. Therefore, extrusion synergistic gallic acid has improved the structure and properties of yam starch-related products, which can provide new directions and new ideas for the development of yam starch.

Nutritional Traits, Pasting Properties and Antioxidant Profile of Selected Genotypes of Sorghum, Oat and Maize Eligible for Gluten-Free Products

The technological and nutritional traits of food-grade sorghum hybrids, hulled/naked oat varieties and maize genotypes of different colors were studied for novel and healthier gluten-free foods. Oat genotypes showed the highest protein content, followed by maize and sorghum. The total starch and the total dietary fiber content were quite similar among the three species. Great variation was found in the amylose content, and the highest was in sorghum (27.12%), followed by oat 16.71% and maize 10.59%. Regarding the pasting profile, the rank of Peak Viscosity was sorghum (742.8 Brabender Unit, BU), followed by maize (729.3 BU) and oat (685.9 BU). Oat and sorghum genotypes had similar average breakdown (407.7 and 419.9 BU, respectively) and setback (690.7 and 682.1 BU, respectively), whereas maize showed lower values for both parameters (384.1 BU and 616.2 BU, respectively). The total antioxidant capacity, only in maize, significantly correlated with total flavonoid, phenolic and proanthocyanidin contents, indicating that all the measured compounds contributed to antioxidant capacity. The study indicated the importance of sounding out the nutritional and technological characteristics of gluten-free cereals in order to select suitable cultivars to be processed in different gluten-free foods with better and healthier quality.

Morphological, Structural, Thermal, Pasting, and Digestive Properties of Starches Isolated from Different Varieties of Rice: A Systematic Comparative Study

The aim of this study was to compare the properties of isolated starches from ten commonly consumed rice varieties in China and to investigate their possible association. In addition, principal component analysis (PCA) and correlation analysis were performed to demonstrate the weight or relevance of different properties. The starch granules had an irregular polyhedral structure. The crystalline structure had an orthogonal arrangement, which is characteristic of A-type starch with nanocrystals with an orthorhombic crystal structure. In addition, higher levels of rapidly digestible starch (72.43 to 74.32%) and resistant starch (2.27 to 2.3%) were found in glutinous rice starch. The highest content of slowly digestible starch (59.48%) was found in starch isolated from black rice, which may be an ideal rice variety for controlling blood glucose and weight. Starch isolated from red Hani terrace rice showed the highest thermal stability during cooking and the highest resistance to a high shear force treatment. In addition, the PCA suggests that the amylose content of starch largely determines the functional properties of starch and positively correlates with the peak viscosity and setback viscosity of the starch pasting. The results of this study will enrich the scientific knowledge of various rice starches and promote their application in the food industry and other industries.

Internal Quality Assessment of East African Highland Cooking Banana (Musa spp.) Flour: Significance for Breeding and Industrial Applications

This study assessed the internal quality traits of East African Highland cooking banana flours, exploring their significance for breeding and potential industrial applications. Twenty cultivars (nine hybrids and eleven landraces) were used. Swelling power capacity, water solubility, water absorption capacity, water absorption index, freeze-thawing stability, and pasting characteristics of banana flour were assessed using standard methods. The results showed that cultivars with high swelling power also exhibited a high water absorption capacity and water absorption index, thus making them suitable for bakery industries. The water absorption capacity ranged between 5.66% (N2) and 11.68% (N11). Landraces KBZ (9.01) and NKYK (8.05), and hybrids N11 (11.68) and N9 (8.48) are suitable as thickeners due to high WAC. Hybrids (N7, 27.83%, and N9, 22.59%) and landraces (NMZ, 32.69%, and NFK, 34.24%) had low freeze-thawing stability, hence it is applicable as a food stabilizer. Landrace NKT (19.14%) and hybrid N9 (16.95%) had the highest solubility, and landrace KBZ (6.93%) and hybrid N3 (6.66%) had the lowest solubility. Landraces MSK (6265), NKY (3980), and NFK (3957), and hybrids N6 (3608), N7 (3505), and N9 (3281 RVU) had high peak viscosity. The trough viscosity, final viscosity, and breakdown viscosity of cultivars varied from 422.5 to 5004 RVU. The landraces MSK (5021 RVU) and NFK (4111 RVU) had the highest final viscosity, making them suitable for application in the food industry for thick and stable sauces. Landrace TRZ had the lowest pasting temperature (62.7 °C), making it advantageous for use where fast gelatinization is required, hence saving energy costs and cooking time. These findings suggest that the genetic attributes inherent in cultivars can be incorporated into breeding programs targeting required traits for industrial application.

Effect of oil extraction on physicochemical and structural properties of starch isolated from acorn (Quercus brantii)

Acorn (Quercus brantii) is a rich source of starch. Since the presence of lipids affects the physicochemical properties of starch and the extraction of nutritious acorn oil and its starch is economical, it's essential to study the acorn starch characteristics before and after oil extraction. Firstly, the best condition for reaching the maximum extraction yield of acorn starch (AS) was determined, and defatted acorn starch (DAS) was extracted in the same conditions. Then the physicochemical properties of both samples were compared. The structural properties were investigated by Scanning Electron Microscopy images. The maximum yield of AS was obtained in a 1:10 ratio (acorn flour: water) at 45 °C and 180 min. Results demonstrated significant differences between color parameters and fat content (0.65 ± 0.04 and 12 ± 0.02) of AS and DAS. Also, DAS had higher swelling power, solubility, and lower turbidity than AS. The X-ray diffraction pattern showed that AS was C-type with relative crystallinity of 27.77 %. Pasting, thermal, and textural properties reflected the higher viscosity, gelatinization, retrogradation, and hardness for DAS compared to AS. Consequently, all of these analyses exhibited structural changes in acorn starch by removing lipids from acorn flour and provided essential information for further applications of acorn starch in different industries.

Interaction of starch and non-starch polysaccharides in raw potato flour and their effects on thickening stability

The present study sought to explore the potential of raw potato flour prepared from two common potato varieties (Atlantic and Favorita) as a thickener and the underlying mechanisms of its thickening stability based on the chemical component content, chemical group, starch, pectin, cell wall integrity, and the cell wall strength of raw potato flour. The raw potato flour prepared from Favorita potato (FRPF) showed great potential as a thickener with a valley viscosity/peak viscosity of 97.24 %. Additionally, the viscosity of FRPF after heat treatment, acid treatment and shear treatment was maintained at 70.73 %, 65.99 % and 78.89 % of the original viscosity, respectively, which is better than that of ARPF (44.98 %, 47.03 % and 61.57 %, respectively). The results also revealed that high pectin content, cell wall integrity and strength contributed significantly to the thickening stability of potato meal, which was achieved by limiting the swelling and disintegration of starch. Finally, the correctness of the principle was verified using the raw potato flour prepared from four types of potatoes (Heijingang, Innovator, Qingshu No. 9, and Guinongshu No. 1). Overall, the development of thickener from raw potato flour has broadened the variety of clean label additives in the food industry.

Evaluation of commercial rice grains present in the Amman market

Rice is a staple food that contributes to significant energy intake. Jordan relies on importing to provide the market with the required quantities of rice. Different varieties from different sources with various qualities are available in the market. This study aimed to evaluate the quality of rice available in the markets in Amman city-Jordan. Twenty-five brands (three samples from each brand) were collected. Samples were evaluated regarding chemical composition, dimensions before and after cooking, percentage of different defects, pasting profile (pasting temperature, peak viscosity, peak time, trough, and final viscosity), whiteness, transparency, and milling degree. All rice samples tested comply with the Jordanian standard except for chalky kernels (four brands), heat-damaged kernels (one brand), and insect infestation (two brands). All samples that did not fulfil the Jordanian specifications were from the long-grain rice. Medium-grain rice has higher whiteness, transparency, milling degree, moisture, starch, peak viscosity, trough, and final viscosity than long-grain rice. On the other hand, long-grain rice has a higher protein, pasting temperature, and peak time. There were significant differences in pasting and chemical composition parameters within the two groups of grain sizes. The average elongation ratio for all samples was 1.57 ±0.14, with significant differences between different brands. Due to the higher pasting temperature and peak time, long-grain rice requires more energy during cooking than medium-grain rice.

Current trends in the preparation, characterization and applications of oat starch - A review

Worldwide consumption of oats is gaining popularity due to its composition and multifunctional benefits of individual components. Oat starch being the major component accounts up to 60% of the dry weight of kernel, possess small granule size and high lipid content. Properties of starch substantially affect the quality of the product. Modification and characterization of starch is important for their specific applications that increase the utilization of oat starch. Different modification techniques greatly affect the functional, pasting, gelatinisation, textural, rheological, retrogradation properties and enzymatic digestibility of oat starches in comparison to native starch. Modified oat starch competes against other abundant and inexpensive cereal starches (rice and corn) that are available in modified forms in the market. This review summarises the current knowledge of physicochemical, morphological, pasting, functional, rheological and gelatinization properties, developments in the extraction and modification (physical, chemical and enzymatic) and applications of oat starch. Thus, this review will upgrade the scientific basis on oat starch being a unique source of starch for variety of applications.

Genetic and phenotypic characterization of rice grain quality traits to define research strategies for improving rice milling, appearance, and cooking qualities in Latin America and the Caribbean

Rice (Oryza sativa L.)grain quality is a set of complex interrelated traits that include grain milling, appearance, cooking, and edible properties. As consumer preferences in Latin America and the Caribbean evolve, determining what traits best capture regional grain quality preferences is fundamental for breeding and cultivar release. In this study, a genome-wide association study (GWAS), marker-assisted selection (MAS), and genomic selection (GS) were evaluated to help guide the development of new breeding strategies for rice grain quality improvement. For this purpose, 284 rice lines representing over 20 yr of breeding in Latin America and the Caribbean were genotyped and phenotyped for 10 different traits including grain milling, appearance, cooking, and edible quality traits. Genetic correlations among the 10 traits ranged from -0.83 to 0.85. A GWAS identified 19 significant marker/trait combinations associated with eight grain quality traits. Four functional markers, three located in the Waxy and one in the starch synthase IIa genes, were significantly associated with six grain-quality traits. These markers individually explained 51-75% of the phenotypic variance depending on the trait, clearly indicating their potential utility for MAS. Cross-validation studies to evaluate predictive abilities of four different GS models for each of the 10 quality traits were conducted and predictive abilities ranged from 0.3 to 0.72. Overall, the machine learning model random forest had the highest predictive abilities and was especially effective for traits where large effect quantitative trait loci were identified. This study provides the foundation for deploying effective molecular breeding strategies for grain quality in Latin American rice breeding programs.

QTL mapping for starch paste viscosity of rice (Oryza sativa L.) using chromosome segment substitution lines derived from two sequenced cultivars with the same Wx allele

BACKGROUND

The eating and cooking qualities (ECQs) of rice (Oryza sativa L.) are key characteristics affecting variety adoption and market value. Starch viscosity profiles tested by a rapid visco analyzer (RVA) offer a direct measure of ECQs and represent the changes in viscosity associated with starch gelatinization. RVA profiles of rice are controlled by a complex genetic system and are also affected by the environment. Although Waxy (Wx) is the major gene controlling amylose content (AC) and ECQs, there are still other unknown genetic factors that affect ECQs.

RESULTS

Quantitative trait loci (QTLs) for starch paste viscosity in rice were analyzed using chromosome segment substitution lines (CSSLs) developed from the two cultivars 9311 and Nipponbare, which have same Wx-b allele. Thus, the effect of the major locus Wx was eliminated and the other locus associated with the RVA profile could be identified. QTLs for seven parameters of the starch RVA profile were tested over four years in Nanjing, China. A total of 310 QTLs were identified (from 1 to 55 QTLs per trait) and 136 QTLs were identified in more than one year. Among them, 6 QTLs were stalely detected in four years and 26 QTLs were detected in at least three years including 13 pleiotropic loci, controlling 2 to 6 RVA properties simultaneously. These stable QTL hotspots were co-located with several known starch synthesis-related genes (SSRGs). Sequence alignments showed that nucleotide and amino acid sequences of most SSRGs were different between the two parents. Finally, we detected stable QTLs associated with multiple starch viscosity traits near Wx itself, supporting the notion that additional QTLs near Wx control multiple characteristic values of starch viscosity.

CONCLUSIONS

By eliminating the contribution from the major locus Wx, multiple QTLs associated with the RVA profile of rice were identified, several of which were stably detected over four years. The complexity of the genetic basis of rice starch viscosity traits might be due to their pleiotropic effects and the multiple QTL hot spots. Minor QTLs controlling starch viscosity traits were identified by using the chromosome segment substitution strategy. Allele polymorphism might be the reason that QTLs controlling RVA profile characteristics were detected in some known SSRG regions.

Grain quality evaluation of japonica rice effected by cultivars, environment, and their interactions based on appearance and processing characteristics

Appearance and processing characteristics of 45 japonica rice samples, collected from different regions in Jiangsu province, were investigated and evaluated in this study. Specifically, the chalkiness degree had been presented significant differences among different cultivars and regions. The average chalkiness degree varied from 6.81% to 15.34% for different regions and from 1.93% to 28.31% for different cultivars. The minimum head rice rate of cultivars from four regions, NJ9108 (HA), was 80.5%. The AC of CNG10, HD5, and PJ surpassed 13.68% and lower than 11.33% for the others. The protein content ranged from 6.1% to 11%, and the taste value was significantly different among cultivars. In addition, the RVA curves of the samples were similar, but the peak viscosities of NG8 and NJ5055 were higher than others, and there were significant differences in RVA traits among regions. Cultivars were the main reasons for the difference in appearance and processing quality of japonica rice, while environmental factors had leaded to the change of rice composition, texture, and gelatinization.

Effect of cassava starch structure on scalding of dough and baking expansion ability

Fermented cassava products are important starchy food staples in South America. The quality of the products is affected by the baking expansion ability of the dough, which is in turn influenced by the starch fermentation process and drying method employed. We investigated the structural properties of cassava starch after different fermentation and drying treatments, and the effect of starch structure on scalding of dough and baking expansion ability. Fermentation combined with either exposure to sunlight or UV light treatment resulted in high cassava starch baking expansion. Moreover, we observed decreased crystallinity and increased disordered crystalline regions with lower molecular weight in the two types of starch-fermented combined with sunlight or UV light treatment-and both appeared to have a continuous network structure and polarized cross in scalded dough, which are conducive to holding gas and losing water, thus promoting high baking expansibility.

Quantitative characterization of the digestive viscosity profile of cereal soluble dietary fibers using in vitro digestion in Rapid ViscoAnalyzer

A standard method measuring viscosity (η) of cereal products through in vitro digestion in a Rapid ViscoAnalyzer has been developed previously and is predictive of some physiological effects of cereal foods. This paper proposes a simple mathematical model to analyze quantitatively the digestograms obtained by that method. Digestograms of twelve uncooked and cooked cereal products were generated and data quality was assessed. Experimental data were fitted with a viscosity model η_model=η₁+η₂, where [Formula: see text] and [Formula: see text] were respectively viscosity decrease and viscosity increase components. The model showed very good agreement with experimental data and enabled interpretation of the digestograms in relation to the composition of the products: η₁ was interpreted as the decreasing viscosity of digestible polymeric nutrients whereas η₂ was interpreted as the viscosity development of viscous dietary fibers. This model may be useful to investigate quantitatively the biological effects of soluble dietary fibers in cereal products and similar products.

Physicochemical properties and structure of modified potato starch granules and their complex with tea polyphenols

The physicochemical, rheological properties and structure of potato starch and starch-tea polyphenols (TPs) complex modified by enzyme and alcohol was investigated in this study. Cavities on the modified starch granules and morphology change could be investigated by SEM, while significant birefringence observed in complete granules by polarizing light microscope, but disappeared in crashed starch. TPs inhibited the aggregation of amylose and retrogradation of starch-TPs complex, resulting in the decrease of gel strength, and the increase of viscosity and gelatinization stability of starch granules. Fourier transform infrared (FT-IR) spectra showed that intramolecular hydrogen bond could be formed between TPs with modified starch, and the hydrogen bond force formed by starch and TPs was stronger than that between starch molecules. X-ray diffraction (XRD) analysis revealed that three modification methods did not change the crystalline structure of starch, but new diffraction peaks appeared in the four starch-TPs complex, suggesting that the hydrogen bond was incurred by interaction between TPs and amylose to form V-type crystalline. These results demonstrated that the complex formed by TPs and native/modified potato starch could be used in food industrial applications due to the inhibition of starch retrogradation.

Development of High-Moisture Meat Analogues with Hemp and Soy Protein Using Extrusion Cooking

The interest in plant-based products is growing in Western countries, mostly due to health and environmental issues that arise from the consumption and production of animal-based food products. Many vegan products today are made from soy, but drawbacks include the challenges of cultivating soy in colder climates such as northern Europe. Therefore, the present study investigates whether industrial hemp (Cannabis sativa) could substitute soy in the production of high moisture meat analogues (HMMA). A twin screw co-rotating extruder was used to investigate to what extent hemp protein concentrate (HPC) could replace soy protein isolate (SPI) in HMMAs. The substitution levels of HPC were 20 wt%, 40 wt% and 60 wt%. Pasting properties and melting temperature of the protein powders were characterized by Rapid Visco Analyzer (RVA) and Differential Scanning Calorimeter (DSC), respectively and the produced HMMA was analysed by determining the texture and colour attributes. The results showed that it is possible to extrude a mixture with up to 60% HPC. HPC absorbed less water and needed a higher denaturing temperature compared to SPI. Increasing the moisture content by 5% would have resulted in a reduction of hardness and chewiness. The lightness (L* value) was found to be significantly higher in SPI product and decreased in the mixture with higher HPC (p < 0.05).

Oat starch: Physico-chemical, morphological, rheological characteristics and its applications - A review

Oat starch is getting attention owing to its usefulness and potential in a number of food and non-food applications. Starch is by far the main component of oat grains and possesses some unique chemical, physical, and structural properties when compared with other cereal starches. Oat starch offers untypical properties such as small size of granules, well-developed granule surface and high lipid content. Variation in amylose and amylopectin proportion along with the properties associated with the amylopectin molecule makes diversity in composition of oat starch. The pasting and rheological properties of oat starches control food product quality. This review articles outlines the recent developments in understanding of the starch isolation, chemical composition, morphology, pasting, rheological and thermal characteristics and various application of oat starch. Potential applications of oat starches are also reviewed.

Genetic Variation of Physicochemical Properties and Digestibility of Foxtail Millet (Setaria italica) Landraces of Taiwan

Foxtail millet is considered a 'smart food' because of nutrient richness and resilience to environments. A diversity panel of 92 foxtail millet landraces preserved by Taiwan indigenous peoples containing amylose content (AC) in the range of 0.7% to 16.9% exhibited diverse physiochemical properties revealed by a rapid viscosity analyzer (RVA). AC was significantly correlated with 5 RVA parameters, and some RVA parameters were also highly correlated with one another. In comparison to rice, foxtail millet contained less starch (65.9-73.1%) and no significant difference in totals of resistant starch (RS), slowly digestible starch (SDS), hydrolysis index (HI), and expected glycemic index (eGI) according to in vitro digestibility assays of raw flour with similar AC. RS was significantly positively correlated with AC and four RVA parameters, cold paste viscosity (CPV), setback viscosity (SBV), peak time (PeT), and pasting temperature (PaT), implying that suitable food processing to alter physicochemical properties of foxtail millet might mitigate hyperglycemia. This investigation of pasting properties and digestibility of diverse foxtail millet germplasm revealed much variation and showed potential for multi-dimensional utilizations in daily staple food and food industries.

Comparison of pasting properties measured from the whole grain flour and extracted starch in barley (Hordeum vulgare L.)

Pasting properties of barley starch are important characteristics from a processing standpoint. The isolation of starch form barley grains is time consuming thus the whole grain flour is always used. To compare pasting properties of starch with those of the whole grain flour, we used a Rapid Visco Analyser (RVA) to measure pasting properties of three types of samples: grain flour and starches isolated using two different extraction methods. We also investigated compositional, morphological and structural properties of the two starch samples. Significant differences in pasting properties were found among the three sample types, but most of the parameters of pasting properties displayed significant correlations between flour and starch. No significant differences were found in amylose/amylopectin ratio, granule morphology, granule size distribution and crystal structure between starches extracted using two different methods. However, the starch isolated from water homogenization had a higher protein content and lower total starch, amylose and amylopectin contents than the starch extracted with homogenized extraction under alkaline conditions. We concluded that the whole grain flour can be used to predict the pasting properties in breeding programs.

Gene Expression Profiling in Short-Term Imbibition of Wheat: Tools for Dissecting of Pasting Properties of Imbibed Wheat Seeds

Germination of wheat maximizes phytochemical content and antioxidant activity while altering chemical composition, gluten content, and pasting properties. This study investigated the effect of short-term imbibition on gene expression profiles and the physical and functional characteristics of wheat. Changes in gene expression profiles of wheat during short-term imbibition (0, 16, and 24 hr) were evaluated by DNA microarray analysis. Gene Ontology (GO) analysis was carried out to categorize the function of genes with altered expression. Genes related to cellulose and cell wall synthesis were upregulated by imbibition for 16 hr, whereas those associated with polysaccharide catabolism and nucleosome assembly were upregulated in the subsequent 8 hr. The genes related to proteases and gluten were expressed in dry seeds but disappeared after 16 hr of imbibition. Genes encoding α-amylase were not expressed in dry seeds whereas those encoding β-amylase were expressed in dry seeds and downregulated by imbibition. According to quantitative real-time PCR and enzymatic activity assay, α-Amylase expression increased by imbibition and reached a maximum 24 hr after imbibition, with a corresponding increase in enzymatic activity. Pasting properties of flour made from wheat seeds imbibed for different times were decreased when seeds were imbibed for over 16 hr, by examination with Rapid Visco Analyzer. Gluten content did not significantly change until 24-hr imbibition, although expression of genes encoding gliadin and glutenin disappeared by 16-hr imbibition. The data indicated that it was possible to use 16-hr imbibed wheat, with up to the 50% w/w replacement of nonimbibed wheat.

Characterization and Mutational Analysis of a Monogalactosyldiacylglycerol Synthase Gene OsMGD2 in Rice

Monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the two predominant galactolipids present in the photosynthetic membrane in many photosynthetic organisms, including algae and higher plants. These galactolipids are the main constituents of thylakoid membrane and are essential for chloroplast biogenesis and photoautotrophic growth. In silico analysis revealed that rice (Oryza sativa L.) genome has three genes encoding MGDG synthase (OsMGD1, 2, and 3). Although subcellular localization analysis demonstrated that OsMGD2 is localized to chloroplast, its expression was observed mainly in anther and endosperm, suggesting that MGDG might have an important role in the development of flower and grain in rice. Knock-out mutants of OsMGD2 were generated employing the CRISPR/Cas9 system and their morphology, yield and grain quality related traits were studied. The leaf of osmgd2 mutants showed reduced MGDG (∼11.6%) and DGDG (∼9.5%) content with chlorophyll a content decreased by ∼23%, consequently affecting the photosynthesis. The mutants also exhibited poor agronomic performance with plant height and panicle length decreased by ∼12.2 and ∼7.3%, respectively. Similarly, the number of filled grains per panicle was reduced by 43.8%, while the 1000 grain weight was increased by ∼6.3% in the mutants. The milled rice of mutants also had altered pasting properties and decreased linoleic acid content (∼26.6%). Put together, the present study demonstrated that OsMGD2 is the predominantly expressed gene encoding MGDG synthase in anther and grain and plays important roles in plant growth and development, as well as in grain quality.