Journal of Cereal Science最新文献

Owing to the increasing role of fiber-rich wholegrain products in food preparation, it is necessary to determine the optimal ratio of protein to fiber in wholewheat flour. The effects of organic and mineral N fertilizers on the protein content (PC) and total content of arabinoxylans and β-glucans (AX+BG) and their ratio (PC:AX+BG) were investigated here. The effect of this ratio on the dough quality of winter wheat ‘Fredis’ was evaluated. The field experiment was conducted at the Estonian University of Life Sciences in 2014‒2017. The results showed that the total amount of AX+BG was significantly affected only by weather conditions (air temperature and precipitation). Higher total AX+BG was associated with higher water absorption capacity, longer dough development time, and a higher quality number of the dough. Better dough quality indicators were obtained when the PC:AX+BG ratio was in the range of 2‒2.2:1. The value of the PC:AX+BG ratio depended more on fiber content than on PC, because the variation in fiber values between trial years was up to three times greater than that of PC. Better dough quality was obtained from N treatments with higher organic and mineral N amounts and in years with lower or average grain yield.

Superheated steam (SS) treatment has emerged as a pivotal technique for improving cereal quality, specifically rice quality in the present studies. This study investigated the effects of SS treatment on the physicochemical characteristics and cooking attributes of pigmented dehusked rice, focusing on three rice varieties: black rice (BLR), red rice (RR), and brown rice (BR). Employing SS treatment was found to not only preserve the desirable appearance of pigmented dehusked rice but also to significantly reduce its cooking duration and overall hardness. A notable preservation of total phenolic content is observed in BLR, contrasting with a pronounced reduction ranging from 41.96% to 46.38% in RR and 26.13%–48.14% in BR. Flavonoid levels across all rice varieties declined to varying extents, from 1.42% to 8.03% in BLR, 8.20%–16.39% in RR, and 28.61%–46.50% in BR, accompanied by a significant reduction in anthocyanin content. Furthermore, SS treatment substantially elevated the total volatile organic compounds in cooked BLR. This study highlights the nuanced impact of SS treatment across different rice varieties, offering insights into its potential for enhancing the culinary and nutritional value of pigmented cereals.

A novel technique has been developed to increase γ-aminobutyric acid levels and enhance the quality of germinated brown rice (GBR) by ultrasound and enzyme treatment. The combined use of ultrasonic and enzyme treatments notably enhanced the germination rate of brown rice. Additionally, the γ-aminobutyric acid content substantially improved from 18.79 ± 1.87 mg/100 g to 38.60 ± 3.19 mg/100 g when compared to the untreated group. Moreover, the cracks produced on the GBR surface and disruption of the starch structure resulted in increased water absorption, shortening of cooking time, and reduction in GBR hardness, thereby improving the cooking and edible quality of GBR. Additionally, ultrasonic and enzyme treatments increased the amount of fast-digestible starch and enhanced starch digestibility. However, they had minimal impact on the crystal structure, degree of crystallinity, and heat energy changes during the starch pasting process of GBR.

The aim of this study was to investigate the effect of microwave-assisted hydrothermal process on color, solvent holding capacity, damaged starch content, resistant starch content, gelation and textural properties of wheat, barley, and rye flours. The hydrothermal treatment was conducted by adjusting the moisture content of the flours to 20, 25, 30, 35% following drying of the hydrated flours using a modified microwave oven until the moisture content fell below 8%. As a result, a general increase was observed in solvent (water, lactic acid, sucrose, and sodium carbonate) holding capacity, damaged starch content, b* value, chroma (saturation), redness, ΔE value, and gelatinization temperature of the flours regardless of the cereal type. The variations were more pronounced at higher initial moisture contents. On the contrary, the resistant starch content, L* value, whiteness, and breakdown viscosity decreased as a result of the treatment. The hydrothermal treatment resulted in an increase in maximum viscosity, setback viscosity, and gel hardness for wheat flour, whereas it led to a decrease in these parameters for treated barley and rye flours. Moreover, the impact of the treatment varied depending on the initial moisture content, with a more significant effect observed at moisture contents exceeding 25%.

Previous reports have shown that noni (Morinda citrifolia L.) puree extract (NPE) is a promising source of cysteine peptidases with potential applications in the food industry. This study expanded the applications of cysteine peptidases from noni fruit by analyzing their potential for wheat gluten hydrolysis and assessing their in vitro toxicity as a new food ingredient. NPE cysteine proteases hydrolyze both gliadins and glutenins, reaching a degree of hydrolysis of 24.40% and 31.78%, respectively. In addition, they reduced gliadin content by 96.80% after 4 h of incubation, as displayed by the R5 ELISA test kit for detecting gliadin based on the monoclonal antibody R5. The chromatographic fractionation of NPE cysteine proteases on a cation exchange column (Source 30S) resulted in an unretained peak (P1) and a retained peak (P2), which showed proteolytic activity with different electrophoretic and zymographic profiles. P1 and P2 had similar (p < 0.05) degrees of hydrolysis for gliadins (approximately 9%). P1 performed better (10.68%) than P2 (8.55%) for glutenins. NPE cysteine proteases did not exhibit genotoxicity or cytotoxicity against mouse fibroblasts (L929 cell line). These findings suggest that NPE cysteine proteases have potential for use as novel ingredients to produce gluten-free foods.

The functionality (e.g., emulsifying ability) of rice protein (RP) is restricted largely by its low solubility. The formation of a co-assembly with RP and an exogenous protein through pH-cycle is one promising method, but the mechanism behind this has not been revealed. This study utilized ovalbumin (OVA) to improve the solubility of RP and investigated the effect of OVA on the physicochemical characteristics of RP, the interactions between RP-OVA co-assembly and water, the RP-OVA interactions, the key subunits related to the solubility improvement of RP, and the emulsifying capacity of the co-assembly. The formation of RP-OVA co-assembly considerably improved the solubility of RP (up to 73.12%), and the multi-level structure and surface property of RP were altered by OVA. The mechanism for the solubility increase was the hydrophobic interactions between OVA and RP, resulting in the exposure of some hydrophilic amino acids to protein surface and further generating a low surface hydrophobicity that allow more water molecules to permeate. Eight subunits in RP were critical for its solubility increase. The RP-OVA co-assembly prepared in this study showed an emulsifying ability even better than whey protein isolate (a commercial emulsifier) in high internal phase emulsion. This study may guide the solubility improvement of RP and widen the application of RP in the food industry as an emulsifier.

The use of intra-crop diversity (e.g.: variety mixtures) in bread wheat cropping is getting popular in Europe, mostly for agronomic purposes. However, much less is known about the implications on baking quality.

In this paper, we formalized and tested a framework based on two hypothetical mechanisms for mixture effects as a result of plant interactions within mixtures: (i) proportion shifts, relating to changes in grain weight proportion of the varieties at harvest and (ii) component alteration, relating to changes in the baking quality of the component varieties. To test this framework, we measured several baking quality indicators on twelve variety mixtures and their component varieties in pure stands. By recording varietal proportions at harvest, we could measure the relative importance of both mechanisms in explaining observed mixture effects.

Our results showed that proportion shifts explained a large share of mixture effects on protein baking quality (Zélény sedimentation index and W baking strength) but failed to explain mixture effects on protein content in one year and Hagberg's falling number in both years. Our results also suggest component alteration on protein content resulting from altered nitrogen uptake in mixtures, and possibly on Hagberg's falling number resulting from lodging reduction in mixtures.

High-amylose wheat flour has the potential to improve the nutritional value of end products due to a higher resistant starch content than common wheat flour. High-amylose (45% amylose) and type 0 (control, 28% amylose) wheat flours were used for the production of bread. In particular, the direct bread-making method where all the ingredients are mixed together was compared with indirect process carried out in several steps. Various parameters like moisture, weight, volume, resistant starch and crumb hardness were evaluated during a storage period of seven days. The collected outcomes showed that bread with a high amylose content had higher moisture content and lower volume after baking and during storage, regardless of the production method used. The amount of resistant starch, which was four times higher than in type 0 control bread, remained unchanged during the storage. The initial and final values of crumb hardness were similar for the different breads, but fitting the hardness data to a kinetic model, it was found that the staling of high-amylose bread was slower than that of type 0 control bread. Overall, the results of this study demonstrated that high-amylose flour can be used to produce high quality bread with improved nutritional properties.