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Summary: This research explored the effect and mechanism of aspartic acid (Asp) on the darkening of fresh wet noodles (FWNs). With increase in the addition of Asp (0.1%‐0.9%), ΔL* and pH of FWN reduced significantly (P < 0.05). Asp could reduce polyphenol oxidase (PPO) activity and increase its retention rate of polyphenol of FWN. When FWNs were adjusted to the same pH by Asp, malic acid (Mal) and hydrochloric acid (HCl), ΔL* and PPO activity of FWN with Asp were lower than that of other two acids. In the vitro PPO solution, the inhibitory effect of Asp on PPO activity was related to the decrease in pH and the ability of chelating Cu2+. According to UPLC‐TOF‐MS analysis, Asp could also react with PPO browning products (‐C12H9O4, ‐C24H19O2 and ‐C12H7O5), transforming browning products into some light‐coloured products. Asp effectively inhibited the darkening of FWN and had the potential use in noodle industry. [ABSTRACT FROM AUTHOR]

Summary: The effect of adding barley (Hordeum vulgare L.) β‐glucan (BBG) to dough on the water redistribution and the thermal properties of dough was studied by TGA and DSC. Combined with LF‐NMR to analyse the competition and redistribution mechanism of water at the 1H level. The mass loss of the dough measured by TGA was reduced by an average of 2.11% with BBG added. BBG increased the water retention of the dough, delayed the water loss process. The LF‐NMR results showed that at the same water absorption the T21 of the 3% BBG dough was longer while its T22 was shorter than those of the control. BBG has different effects on the different states of water in the dough. BBG increased the free sulfhydryl content in dough during heating, while the adverse effects of BBG on the biopolymer reactions, such as disulfide bond, could be partially relieved by regulating water content. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to study the effect of ozone treatment on the quality of bread and its shelf life. Flour was treated with ozone gas a rate of 5 L/min for 5, 15, 25, 35, and 45 min. Baking studies showed that bread made from flour treated with ozone for 15 min exhibited improved quality properties (in terms of specific volume, bread color, and crumb cell numbers). Exposure to ozone for shorter times did not cause obvious changes in the major volatile compounds of bread. A shelf life tests showed that ozone gas treatment influenced the extent of starch crystallinity. The relative starch crystallinity of bread made from flour treated with ozone for 15 min was lower than the control value, as were the hardness, springiness, and cohesiveness. Microscopic examination of crumb structure revealed remarkable differences between control and treated breads. Practical applications: Although ozone is a naturally occurring substance found in the atmosphere, ozone can also be produced synthetically. Recently, ozone has come to be regarded as a new treatment for flour. Especially in countries where the chlorination is forbidden, ozone treatment may be of a great interest if it were associated with significant and reliable changes in flour. Ozone treatment of wheat flour tends to improve bread shelf life and quality in terms of physiochemical, baking properties, X‐ray diffraction data, volatile compound levels, crumb structure, and textural characteristics. Given such findings, desirable shelf life and bread qualities may be achieved when ozone is used as a flour oxidant prior to bread baking. Analyses of the effects of ozone gas on treatment of flour on bread shelf life and quality would aid the production of high quality and extend the shelf life of bread. [ABSTRACT FROM AUTHOR]

In this study, critical temperature, pH value, water content, and water activity inducing the acceleration of fresh noodle deterioration were determined. Total plate count (TPC) and L* value were selected as the visualized parameters to characterize the deterioration of fresh noodles based on our previous study. Results showed that the critical temperature leading to the initial acceleration of fresh noodles was 20°C-25°C, critical water content was between 23% and 24%; the fastest darkening rate was detected at pH 8.0-8.5, while microorganisms kept a high growth rate during the whole range of initial pH 6-10. In addition, shelf-life model was built based on the deteriorating dynamics at room temperature, showing that microbial growth could be well fitted by both Gompertz and Logistic model, with higher fitting precision for Gompertz model and the fitting equation was y = 4.364 exp[−exp (1.032-0.086t)], R2 = .98855; Meanwhile, the darkening of fresh noodles could be fitted by quadratic polynomial model, with the fitting equation y = 76.0629 − 0.0165 x + 5.98587 x2, R2 = .9814. Practical applications This article presents the dynamics during the deterioration of fresh noodles and the critical conditions (moisture content and water activity, pH value, and storage temperature) accelerating the deterioration process. In addition, shelf-life model was built based on the deteriorating dynamics of fresh noodles at room temperature. Based on these results, a shelf-life stable fresh noodle product can be developed by applying different processing techniques and by keeping it in appropriate conditions, which will provide great guiding significance for the production and preservation of these products. [ABSTRACT FROM AUTHOR]

This study compared the deterioration of pre-fermented frozen dough in 1–90 days frozen storage (FS) and 1–4 times of freeze–thaw cycles (FT) by analysing the characteristics of steamed bread, its dynamic rheology and rheofermentation properties, gluten aggregation, yeast viability, cell microstructure and yeast metabolites. The results showed that the specific volume and hardness of steamed bread after 25 days of FS and 1 FT were unacceptable. The decrease in the elasticity modulus and the increase in the viscosity modulus caused by FT were more obvious than those caused by FS. The rheofermentation results indicated that both FS and FT decreased the gas retention and gas production ability, but more significant negative effect was observed during FT than during FS. Further investigation of the gluten aggregation showed that the glutenin macropolymer decreased during FS and FT whether yeast was added or not to the dough, and the yeast increased the decline rate from 0.24 to 0.52 when FT was conducted, which indicated that the yeast had a negative effect on gluten aggregation. The yeast viability and microstructure showed no significant difference during FS and FT, whereas the yeast metabolites results demonstrated that the glucose and fructose contents increased during FS but decreased during FT, which indicate a difference in yeast metabolism. Fructose and glucose could be the indicators of the difference in the deterioration mechanism of FS and FT based on the factor analyses. This study provided novel insights on the deterioration mechanism of pre-fermented frozen dough. [Display omitted] • Elasticity and gas retention of frozen dough decreased more during freeze-thaw than frozen storage. • Yeast increased the decline rate of glutenin macropolymer in frozen dough. • Yeast metabolism was related to the deterioration mechanism of frozen dough. • Glucose and fructose increased during frozen storage, but decreased during freeze-thaw. [ABSTRACT FROM AUTHOR]