Search

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 effects of resting under ultrasonic treatment on the properties of whole wheat dough sheets and noodles were investigated. Compared with the control group, the resting time to reach the maximum breaking force and extensibility of whole wheat dough sheets treated with ultrasound was shortened by 20 min. The proportion of strongly bound water (T21) decreased, while the proportion of weakly bound water (T22) increased during resting, and the ultrasonic treatment could accelerate this moisture redistribution in the dough. The extent of the increase in gluten macropolymer and the decrease in –SH content of ultrasound‐treated wheat dough was higher than that of the control one during the initial 5–15 min resting, which could be related to the improvement of whole wheat dough extensibility. Whole wheat noodles showed a better breaking distance for 10 min of ultrasonic‐assisted resting. Ultrasonic treatment could be used to reduce the resting time of whole wheat dough sheets and improve the texture properties of noodles. [ABSTRACT FROM AUTHOR]

Background and objectives: Chinese traditional hand‐stretched dried noodles (CHDN) have been a staple for thousands of years in China and are increasing popular worldwide. NaCl and resting play key roles in the production of CHDN. This study was designed to investigate the combined effect of salt addition and resting on rheology of CHDN dough. Findings: The results of our study showed that the storage modulus (G′), loss modulus (G″), Tanδ, and extensional property of dough increased with the increased levels of NaCl and peaked at 4% NaCl. These changes were due to that salt promoted the aggregation of gluten in dough by increasing the hydrogen bonds and hydrophobic interactions among gluten subunits. The resting process resulted in decreased G′, G″, and extensional strength, while it increased Tanδ, extensibility, and the extensional area, and these were caused by gluten relaxation and gliadin aggregation. The increased addition of NaCl accelerated the change in small deformation rheology of dough during resting but decelerated the change in extensional property. Conclusions: Increased salt additions could increase the extensibility and extensional strength of rested dough and extend the changing time in extensional property of CHDN dough during resting. In conclusion, increased salt addition would enhance the processing property and extend the resting time of dough during the production of CHDN. Significance and novelty: The combined effect of NaCl addition and resting on the rheology of the dough for CHDN preparation and the underlying mechanisms were investigated. This study provides insights into the production of CHDN. [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]

Summary: The aim of this study was to investigate the effects of arabinoxylan with different molecular weight on the wheat dough thermo‐mechanical, rheological, microstructural and water mobility properties. Arabinoxylan was extracted from wheat bran and hydrolysed by endo‐1,4‐β‐xylanase (EC 3.2.1.8 from Trichoderma reesei, 10 000 U g−1) for 2 min (AXM) and 10 min (AXL), respectively. The addition of hydrolysed arabinoxylan AXL increased the stability time, decreased the setback value of wheat dough and enhanced the values of storage modulus (G′) and loss modulus (G″), while unhydrolysed arabinoxylan (AXH) reduced these values. Meanwhile, unhydrolysed arabinoxylan increased T2 relaxation time while hydrolysed arabinoxylan AXL decreased T21 and T22. Confocal laser scanning microscope (CLSM) results showed that the addition of hydrolysed arabinoxylan AXL promoted the formation of a more compact and continuous protein network in wheat dough. These results revealed that compared with high molecular weight arabinoxylan, hydrolysed arabinoxylan could improve the rheological properties and processing properties of wheat dough by enhancing the interaction among water molecules, starch and gluten in wheat dough. [ABSTRACT FROM AUTHOR]

In this study, the impact of characteristics (physicochemical, rheological, and pasting properties) of different wheat flours on the quality of frozen cooked noodles was investigated. In this sample set, results showed the cooking loss of noodles related negatively to flour swelling power. The water absorption of noodles related negatively to the dough stability time, the area, and the resistance to extension. The wheat flour with higher dough development time resulted in frozen cooked noodles with higher hardness, chewiness, and adhesiveness. Springiness of noodles correlated negatively to degree of softening. The tensile properties of frozen cooked noodles were influenced by rheological and pasting properties of wheat flours. The present study indicated high quality of frozen cooked noodles demanded wheat flours with high dough gluten strength, peak viscosity, and final viscosity and with low pasting temperature. [ABSTRACT FROM AUTHOR]

BACKGROUND Bitter taste is the main limiting factor for various applications of protein hydrolysates. Frequently used physicochemical methods for debittering protein hydrolysates come with some undesired side effects. Deamidation-induced modification would be a very promising technique to improve the flavor of wheat gluten hydrolysates ( WGHs). This study was designed to determine the effect of deamidation with certain enzymes or acid treatment on the chemical composition, bitterness and umami properties of WGHs. The difference between umami peptide and free glutamic acid on the suppression of bitterness is emphatically discussed. The optimal scheme is proposed based on the flavor of WGHs and the yield of peptides. RESULTS The generation of umami substances suppressed bitter signal transduction. When the content of umami substances was relatively high, the umami-enhancing properties of umami peptides were obviously effective. The intensity of umami taste was high enough to further suppress bitter taste in the course of neurocognitive functioning. CONCLUSION When WGHs were treated with Glutaminase for 180 min, the umami taste score increased from 1.62 to 4.27 and the bitter taste score decreased from 1.33 to 0.65. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effect of active packaging [oxygen absorber (OA) or oxygen absorber combined with ethanol emitter (OA + EE)] on microbial stability and quality of Chinese steamed bread (CSB) stored at 25 °C. Air-packaged CSB was taken as control. Microbiological, sensory, physical, thermal and mechanical changes were monitored as a function of treatment and storage time. On day 2 of storage total plate count was reduced by 3.1, 3.7 and 4.4 cfu/g by OA, OA + EE (1% v/v) and OA + EE (3% v/v), respectively ( p < 0.05). Yeasts and moulds were inhibited during the entire storage period. No detrimental effects of OA + EE (1% v/v) were observed on organoleptic parameters, whereas OA + EE (3% v/v) gave a strong objectionable flavour and taste. Active packaging significantly ( p < 0.05) delayed the increase of potential of hydrogen as compared to the control. No significant effect of active packaging was found on moisture content, water activity, colour and specific volume. An increase in the melting enthalpy of amylopectin crystallite was observed in all samples during storage. The stored CSB samples packaged with OA showed higher values of hardness compared to samples packaged with OA + EE (1% v/v), indicating the potential of ethanol as plasticizer of the protein network. The results indicate the potential application of OA and OA + EE (1% v/v) as an antimicrobial packaging system for CSB preservation. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Pasta products and noodles have been staple foods since ancient times in many countries all over the world. These cereal products are still increasingly popular worldwide for their convenience, nutritional properties, special flavor, and taste. Pasta and noodles are essentially the same type of food but differ in their raw materials and shaping process, as well as the people and regions in the world consuming them. Many additives have been developed and are being used today in pasta and noodle products for various purposes. However, due to lack of knowledge about specific uses for some additives, they are sometimes misused by manufacturers. This can lead to opposite technological effects instead and may even cause damage to human health. Due to consumer demands, interest now focuses on natural 'green' food additives with broad-spectrum functions, high effectiveness, and low toxicity. In order to provide detailed references for noodle and pasta production, as well as to provide ideas for developing new types of these products, here we summarize the types of natural additives that are being incorporated in pasta and noodle products, mainly for quality improvement and food preservation. [ABSTRACT FROM AUTHOR]

Wheat gluten was hydrolysed by Alcalase 2.4L under ultrasound. Different antioxidant assays in vitro, such as ferrous ion-chelating activity, reducing power, inhibition of linoleic acid emulsion peroxidation and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activity, were employed to evaluate the antioxidant activities of the wheat gluten hydrolysate (WGH) obtained. It was found that WGHL (WGH which was obtained by low frequency (LF) ultrasound) exhibited the strongest antioxidant activities, with an EC value of 0.513 mg mL for ferrous iron-chelating activity, as well as a high and dose-dependent reducing power. In the linoleic acid system, a longer induction time indicated a significant decrease of lipid peroxidation. In addition, WGH also exhibited notable ABTS radical scavenging activity. A good correlation was observed between antioxidant activities and the amount of WGH, but a poor correlation was observed between antioxidant activities and degree of hydrolysis. The molecular weight distribution of WGH was affected by ultrasonic frequency and WGHL had the highest proportion of peptide fractions of molecular weight 3000-500 Da. All the results showed that the WGH treated by ultrasound had strong antioxidant activities and low molecular weight. [ABSTRACT FROM AUTHOR]

The effect of different cooking methods on the flavour of mushroom soup was assessed. The results indicated that the levels of free amino acids and 5'-nucleotides in the microwaved mushroom soup were ( P < 0.05) higher than those in boiled and autoclaved mushroom soup. The number of volatile compounds identified in the boiled mushroom soup was ( P < 0.05) higher than those in autoclaved and microwaved mushroom soup. The main aroma-active compounds found in mushroom soup were 1-octen-3-one (mushroom-like), 3-octen-2-one (cooked mushroom-like), 2,6-dimethyl pyrazine (roast nut), benzeneacetaldehyde (floral), dihydro-5-methyl-2(3 H)-furanone (sweet) and some unknown compounds with popcorn and sauce flavour. In addition, boiled, autoclaved and microwaved mushroom soup possessed thirteen, ten and nine aroma-active compounds (with flavour dilution factors > 1), respectively. Thus the flavour of mushroom soup is dependent on the cooking methods as proved by gas chromatography and olfactometry analysis. [ABSTRACT FROM AUTHOR]

Summary [ABSTRACT FROM AUTHOR]