With the ever-increasing global demand for high quality rice in both local production regions and with Western consumers, we have a strong desire to understand better the importance of the different traits that make up the quality of the rice grain and obtain a full picture of rice quality demographics. Rice is by no means a ‘one size fits all’ crop. Regional preferences are not only striking, they drive the market and hence are of major economic importance in any rice breeding / improvement strategy. In this analysis, we have engaged local experts across the world to perform a full assessment of all the major rice quality trait characteristics and importantly, to determine how these are combined in the most preferred varieties for each of their regions. Physical as well as biochemical characteristics have been monitored and this has resulted in the identification of no less than 18 quality trait combinations. This complexity immediately reveals the extent of the specificity of consumer preference. Nevertheless, further assessment of these combinations at the variety level reveals that several groups still comprise varieties which consumers can readily identify as being different. This emphasises the shortcomings in the current tools we have available to assess rice quality and raises the issue of how we might correct for this in the future. Only with additional tools and research will we be able to define directed strategies for rice breeding which are able to combine important agronomic features with the demands of local consumers for specific quality attributes and hence, design new, improved crop varieties which will be awarded success in the global market.

Amylose content is a parameter that correlates with the cooking behavior of rice. It is measured at the earliest possible stages of rice improvement programs to enable breeders to build the foundations of appropriate grain quality during cultivar development. Amylose is usually quantified by absorbance of the amylose-iodine complex. The International Network for Quality Rice (INQR) conducted a survey to determine ways that amylose is measured, reproducibility between laboratories, and sources of variation. Each laboratory measured the amylose content of a set of 17 cultivars of rice. The study shows that five different versions of the iodine

The quality of rice in terms not only of its nutritional value but also in terms of its aroma and flavour is becoming increasingly important in modern rice breeding where global targets are focused on both yield stability and grain quality. In the present paper we have exploited advanced, multi-platform metabolomics approaches to determine the biochemical differences in 31 rice varieties from a diverse range of genetic backgrounds and origin. All were grown under the specific local conditions for which they have been bred and all aspects of varietal identification and sample purity have been guaranteed by local experts from each country. Metabolomics analyses using 6 platforms have revealed the extent of biochemical differences (and similarities) between the chosen rice genotypes. Comparison of fragrant rice varieties showed a difference in the metabolic profiles of jasmine and basmati varieties. However with no consistent separation of the germplasm class. Storage of grains had a significant effect on the metabolome of both basmati and jasmine rice varieties but changes were different for the two rice types. This shows how metabolic changes may help prove a causal relationship with developing good quality in basmati rice or incurring quality loss in jasmine rice in aged grains. Such metabolomics approaches are leading to hypotheses on the potential links between grain quality attributes, biochemical composition and genotype in the context of breeding for improvement. With this knowledge we shall establish a stronger, evidence-based foundation upon which to build targeted strategies to support breeders in their quest for improved rice varieties.Electronic supplementary materialThe online version of this article (doi:10.1007/s11306-015-0925-1) contains supplementary material, which is available to authorized users.

Potential methods for rapid assay of sweet corn lipoxygenase (LPO) were evaluated and compared by visual inspection. Both model system (partially purified) and vegetable (LPO extract) system studies were carried out. Model system studies indicated that LPO had maximum activity at pH 6.0 and 2.0 mM linoleic acid. Methylene blue bleaching (MBB), carotene bleaching (CB), and potassium iodide-starch (KI-S) methods were evaluated both spectrophotometrically and visually. Both MBB and KI-S methods were effective for the model system. For the vegetable LPO extract systems (sweet corn and green beans), the MBB method indicated positive results for both, the CB method was not effective for either, and the KI-S method was very effective for green beans but not for sweet corn.

Resistant starch (RS) is the portion of starch that escapes gastrointestinal digestion and acts as a substrate for fermentation of probiotic bacteria in the gut. Aside from enhancing gut health, RS contributes to a lower glycemic index. A genome-wide association study coupled with targeted gene association studies was conducted utilizing a diverse panel of 281 resequenced Indica rice lines comprising of~2.2 million single nucleotide polymorphisms. Low-to-intermediate RS phenotypic variations were identified in the rice diversity panel, resulting in novel associations of RS to several genes associated with amylopectin biosynthesis and degradation. Selected rice lines encoding superior alleles of SSIIa with medium RS and inferior alleles with low RS groups were subjected to detailed transcriptomic, metabolomic, non-starch dietary fibre (DF), starch structural and textural attributes. The gene regulatory networks highlighted the importance of a protein phosphatase alongside multiple genes of starch metabolism. Metabolomics analyses resulted in the identification of several metabolite hubs (carboxylic acid, sugars and polyamines) in the medium RS group. Among DF, mannose and galactose from the water-insoluble fraction were found to be highly associated with low and medium RS lines, respectively. Starch structural analyses revealed that a moderate increase in RS is also linked to an elevation of amylose 1 and amylose 2 fractions. Although rice lines with medium RS content negatively affected textural and viscosity properties in comparison to low RS, the textural property of medium RS lines was in the same acceptable range as IR64, a rice mega variety popular in Asia.

Plant height; stem thickness; fresh and dry weights of leaves and stems; numbers of leaves, trusses, flowers, and fruits; and leaf concentrations of Cl, Na, N-NO3, K, Ca, and Mg were measured in mature plants from 39 tomato accessions representing five species of Lycopersicon [L. esculentum Mill., L. peruvianum (L.) Mill., L. pimpinellifoliurn (Jusl.) Mill., L. hirsutum H. & B., L. pennellii (Corr.) D'Arcy] in response to various NaCl concentrations. Plants were irrigated with a nutrient solution, plus one of four levels of NaCl with electrical conductivities of 0.28, 0.63, 1.39, and 2.15 S·m-1. Characters were evaluated for each genotype taking into consideration: 1) the significant differences between NaCl concentrations, 2) the experimental errors in the analyses of variance, and 3) the uniformity of response to the salt concentrations. The characters that fulfilled these criteria for all 39 genotypes were: plant height, dry weights of leaves, fresh and dry weights of stems, and leaf concentrations of Cl and Na. However, other characters, although not generally applicable to the entire data set, were good indicators of response differences within a particular species. Leaf concentrations of N-NO3 and Mg were useful indicators in L. pimpinellifolium and L. esculentum and number of leaves and leaf concentration of Mg were useful indicators in L. hirsutum for responses of mature plants to salt stress.

Wheat gluten was modified by enzymatic hydrolysis only or in combination with enzymatic deamidation. When subjected to Maillard reaction, the hydrolysates generated important flavor compounds such as pyrazines and furans. Umamizyme or Flavourzyme was used for hydrolysis whereas Glutaminase Daiwa was used for deamidation. Isolation of volatile compounds was conducted by solid–phase microextraction (SPME) followed by identification by gas chromatography–mass spectrometry (GC–MS). Single or double enzymatic treatment produced same volatiles but in general, deamidation increased the quantities. The major pyrazines identified were methylpyrazine, 2,5-dimethylpyrazine, 2-ethylpyrazine, and 2-methyl-6-propylpyrazine whereas the major furans include 2-furfural, 2-acetylfuran, 2-furfurylalcohol, and 5-methyl-2-furfural. Although similar volatile profiles were obtained in Umamizyme and Flavourzyme systems, much greater amounts of flavor compounds were observed in the former.

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