Rapid analysis of Chinese steamed bread staling using Raman Spectroscopy

Staling is an important issue that Chinese steamed bread(CSB)may encounter during storage,which significantly affects their taste,flavor,and nutritional value.The monitoring technology for rapid aging is particularly important to effectively control the aging process of CSB,reduce quality deterioration,and promote the industrial production of CSB.Raman spectroscopy has been widely used in the study of food structure and properties due to its non-destructive and high-sensitivity characteristics,particularly demonstrating unique advantages in the analysis of starch structure.This study explored the possibility of analyzing the staling of CSB using Raman spectroscopy based on hardness and moisture content.Analysis of the correlation between the hardness of CSB and the full width at half maximum(FWHM)at 480 cm^(−1)during storage was conducted,and a significant positive correlation between them was found,with R^(2)above 0.8.Besides,nine characteristic peaks of CSB samples related to starch were selected for analysis.As the moisture content of CSB decreased,the peak intensities and areas of showed an upward trend during storage,with the best correlation coefficient above 0.8 revealed by linear regression analysis.Therefore,Raman spectra could be used as a potential method for the fast prediction of CSB staling.

Optimizing techno-functionality of germinated whole wheat flour steamed bread via glucose oxidase(Gox)and pentosanase(Pn)enzyme innovation

Germination,a powerful biofortification technique,holds immense potential in bolstering the micronutrient profile of essential staple grains,thereby paving the way for optimal nutritional enhancement.The primary goal of this study was to improve the technological functionality of germinated wheat flour by incorporating pentosanase(Pn)and glucose oxidase(Gox)enzymes,with particular emphasis on the evolutionary changes in its components.The inclusion of Gox did not produce any substantial impact on the volumetric characteristics of the steamed bread.The incorporation of Pn and Gox has been seen to enhance the overall excellence of steamed bread by optimizing loaf volume and textural characteristics while also improving the thermal stability of the dough.The existence of two endothermic peaks could be attributed to bound water or alterations in the granules within the starch crystallization region.Adding Pn and Gox reduced and increased the formation and stability time of the dough,respectively.A certain ratio was employed to assess alternations in the crystallinity of starch granules over a limited range.After steaming,a significant decrease in IR1047/1022 was observed,indicating that the elevated temperature partially disrupted the internal starch crystal structure,leading to a gelatinization reaction with water.The ratio of tensile resistance(R)and elongation(E)of dough increased significantly compared to the control.The results obtained from this study indicate that the simultaneous inclusion of enzymes(Pn+Gox)holds significant promise for expanding the technological functionality of germinated wheat flour dough and improving the quality attributes of steamed bread.

Nutritional evaluation of different cultivars of potatoes(Solanum tuberosum L.) from China by grey relational analysis(GRA) and its application in potato steamed bread making

Chemical composition(moisture,protein,starch,ash,fiber,fat),vitamins(vitamin C,vitamin B1,vitamin B2),total polyphenol content,antioxidant capacity,minerals,and amino acid of 14 potato cultivars in China were evaluated.The results indicated that all parameters varied significantly among different potato cultivars.The total starch,crude protein and fat content ranged between 57.42–67.83%,10.88–14.10% and 0.10–0.73% dry weight(DW),respectively.Moreover,the consumption of potato increased remarkably the dietary intake of vitamins,K,Mn and Cu.In addition,the chemical score of amino acid varied considerably between different cultivars,which ranged from 54(Neida 3 and Neida 41) to 71(Neida 34).Grey relational analysis(GRA) indicated that Neida 26 exhibited the most comprehensive nutritional values among potato cultivars,followed by Neida 42.Different potato flours had a significant effect on the quality parameters of potato steamed bread(PSB),Neida 26 and Neida 34 were more suitable for making PSB.

Effect of Waxy Wheat Flour Blends on the Quality of Chinese Steamed Bread

Steamed bread is very popular in the East and Southeast Asian regions, and its quality is affected by some physicochemical properties. Chinese steamed bread was made by adding waxy flour into normal wheat flour in the present study. The results showed that specific volume was not affected by the proportions of waxy flour, whereas, adding waxy flour decreased the appearance, color, texture, elasticity, stickiness, and the total score of Chinese steamed bread. However, there were no significant differences in all values when the proportions of waxy flour were below 10%. All evaluations but specific volume of Chinese steamed bread were positively influenced by the peak viscosity, resistance, and maximum resistance. When the waxy flour proportions were below 25%, the firmness of Chinese steamed bread stored at -18℃ for 3 days gradually decreased with the increase of waxy flour. It was revealed that the qualities of Chinese steamed bread cannot be improved by waxy flour but it can be widely used in frozen storing food in the future.

Relationship between physicochemical characteristics of Korean wheat flour and quality attributes of steamed bread

The purpose of this study is to identify major factors affecting the manufacture and quality of steamed bread,consumed in Southeast Asia including China,Japan,and Korea.Hence,flours of 11 Korean wheat cultivars were used to evaluate quality attributes of two different styles of steamed bread,Korean style steamed bread(KSSB)and northern-style Chinese steamed bread(NSCSB).KSSB prepared more ingredients and higher optimum water absorption of dough than NSCSB because Korean consumers prefer white and glossy surface and soft crumb.KSSB showed lower height,larger diameter and volume of steamed bread,higher stress relaxation,and softer texture of crumb than NSCSB.The correlation between flour characteristics and quality of steamed bread was different in KSSB and NSCSB.About 90%of variability in the height and volume of KSSB could be predicted from protein content,mixing tolerance of Mixograph,average particle size of flour,final viscosity and solvent retention capacity.Protein content and quality parameters also could explain the variation of steamed bread height in NSCSB.Korean wheat carrying Glu-A3c allele produced higher volume of steamed bread(704.7 mL)than Glu-A3d allele(645.8 mL)in KSSB,although there was no significant difference in volume of NSCSB by glutenin compositions.Glu-D1d and Glu-A3c alleles had softer texture of crumb than Glu-D1f and Glu-A3d alleles in KSSB,Glu-B3i allele also showed lower hardness of crumb than their counterpart allele in NSCSB.Hard wheat showed higher height and volume of steamed bread,and lower stress relaxation and hardness of crumb than soft wheat in KSSB.

Effects of Sourdough Addition on the Quality and Shelf Life of Chinese Steamed Bread

The effect of adding sourdough with lactic acid bacteria(Lactobacillus plantarum M616) on dough quality and the sensory scores, specific volume, crumb firmness, and spread ratio of resultant Chinese steamed bread were studied. The moisture content of crumb and texture characteristics of the Chinese steamed bread with sourdough during storage were analyzed. In this study, 10%,20%, 30%, and 40% of sourdough addition was investigated. The sourdough starter resulted in significant decrease in the water absorption, development time, stability, and farinograph quality number of the dough. The addition of sourdough improved the quality of Chinese steamed bread such as improving the sensory scores and specific volume, decreasing the crumb firmness, and a lower spread ratio was observed with an increase in the sourdough concentration up to 30%. Sourdough addition delayed a fast decrease in the moisture content of the Chinese steamed bread crumb during storage. The texture profile analysis of the bread crumb indicated that the addition of sourdough improved the quality and delayed the staling speed of Chinese steamed bread during storage.Moreover, inclusion of 30% sourdough produced the best protective effect on product staling.

Effect of Pectins on Dough Rheology and Chinese Steamed Bread Quality

Dough preparation and performance are two critical factors influencing the final quality of wheat products. The influence of high and low methoxyl pectins on empirical and dynamic rheological properties of dough and Chinese steamed bread(CSB)quality were investigated. Different concentrations of high methoxyl apple pectin(HMAP), low methoxyl apple pectin(LMAP),and amidation apple pectin(ALMAP) were tested. Results from dynamic and empirical rheological tests indicated that all concentrations of pectins tested(0.2%, 0.6%, and 1%) negatively affected the gluten network. The low methoxyl pectins, LMAP and ALMAP, which had higher anionic densities, resulted in a pronounced weakening of the dough. Meanwhile, dough fermentation properties improved in the presence of appropriate pectins concentrations, and higher maximum dough height, stability of dough pore space, and gas retention were recorded. HMAP was the pectin most effective in influencing dough fermentation properties at all tested concentrations. Regarding CSB quality, textural properties, specific volume, moisture content, and water-holding capacity were analyzed. Generally, the textural properties of CSB were improved, including improved springiness and decreased hardness and chewiness, when 0.2%–0.6% HMAP or LMAP was used. The specific volume of CSB was increased by adding 0.2%–1% HMAP,0.6%–1% LMAP, or 0.2%–0.6% ALMAP. Moreover, CSB moisture loss was progressively reduced in the presence of different pectins at all tested concentrations during storage. In conclusion, pectins, especially HMAP, are good additives for improving the fermentation properties of dough and overall quality of CSB.

Study on Quality Traits for Steamed Bread Made from 25 Representative Wheat Varieties in Shandong Province

In order to study steamed bread quality traits and explore good wheat cultivars, 25 wheat cultivars grown in Shandong province were used through one-process fermentation procedure to examine the variability of steamed bread quality traits and the correlation between quality and score. The results showed that all the steamed bread quality traits expressed large variable coefficient except volume, L* value, l* value and cohesiveness traits, which suggested that the genetic diversity made from wheat in Shandong province was large. The average comprehensive score of the steamed bread was 76.8 for the tested 25 varieties, and ten varieties reached the good steamed bread level, which were Liangxing 99, Luyuan 205, Jimai 22, Jinan 17, Tainong 19, Wennong 17, Huaiyin 84137, and Huaimai 8. The main quality factors affecting the steamed bread score were volume, L* value, A* value, hardness, chewiness, and adhesiveness. Among these factors, the adhesiveness has a significantly positive correlation with the hardness and cohesive, and the volume has a significantly positive correlation with the A* value. The volume, L* value has a significantly positive correlation with score, A* value, hardness and chewiness, and gumminess has a significantly negative correlation with the score. There was no correlation between the score and other traits. The results will benefit the understanding of steamed bread quality in wheat cultivated in Shandong. l

Effects of acetic acid bacteria in starter culture on the properties of sourdough and steamed bread

Sourdough starters for making traditional steamed bread are rich in microbes.Studies have shown that,in addition to yeast and lactic acid bacteria(LAB),acetic acid bacteria(AAB)are other functional species in sourdough,but the influences of AAB on the properties of sourdough and steamed bread were rarely reported.This study aimed to assess the effects of a selected strain of acetic acid bacterium on the properties of sourdough and steamed bread.Sourdoughs and steamed breads were prepared from five different starter cultures,marked as CK(control check,with no starters),Y(only yeast),YL(yeast+LAB),YA(yeast+AAB)and YLA(yeast+LAB+AAB),and their properties were determined.The results of sour dough properties showed that the YLA sourdough had the highest total titratable acid of 14.6 mL and the lowest pH of 3.87 compared with the other groups after fermentation to 8 h;and the YLA sourdough had the greatest elasticity and viscosity.The results of quality properties of steamed bread revealed that the L*value(88.40±0.09)of the YA steamed bread was significantly higher than those of the YLA and YL steamed breads;the YLA steamed bread had the highest specific volume and the highest sensory score of 89.6±3.31 in comparison to those of the other groups;the hardness and chewiness of YLA and YA steamed breads were significantly lower than those of the other groups.Volatile compounds in the steamed breads were also determined by SPME-GC-MS.A total of 42 flavor substances were detected,including 3 kinds of alcohols,8 kinds of aldehydes,7 kinds of ketones,2 kinds of acids,15 kinds of esters,1 furan,and 6 kinds of other types of compounds,mainly alkanes and esters,followed by alcohols and aldehydes.The YLA steamed bread was richer in esters,aldehydes,and acids than those from the other treatment groups.By contrast,alkanes and aldehydes were dominant in the Y and YL steamed breads.Therefore,the flavor and quality of the steamed bread made from the YLA sourdough could be improved obviously.These results could provide references for the application of AAB in dough fermentation and the improvement of new kinds of starters.

Study on the Quality Evaluation of Steamed Bread and the Physical and Chemical Properties of Wheat

In this study,the different physical and chemical properties of wheat were studied,and on this basis,and the quality of steamed bread made was evaluated.We analyzed the correlation between the evaluation indexes of steamed bread and the basic physical and chemical indexes of wheat,and investigated important factors that affect the evaluation indexes of steamed bread,including flour extraction rate,protein content,amylose content,protein,added amount of yeast,fermentation time and other aspects.According to the study results,it was shown that different factors had different effect on steamed bread quality,with both positive correlation and negative correlation.

不同明胶添加量馒头的质构、营养价值及微观结构差异

该研究分析了不同明胶添加量引起的馒头的质构、营养价值及微观结构变化。通过TPA质构分析、感官评定、比容及氨基酸组分测定分析馒头的质构、营养及微观结构等。研究表明,明胶添加量增大,馒头硬度、胶着度及咀嚼性先减小后增大,黏聚性和回复性先升高后降低。明胶添加量为3%时,其硬度、胶着性及咀嚼性最小,弹性、黏聚性及回复性最大,此时馒头比容(1.96)和感官评分(81.72)显著提高,各指标均为最优。添加明胶馒头蛋白质含量比普通白馒头高17.62%,必需氨基酸含量高46.06%,赖氨酸评分高52.12%,总必需氨基酸评分高22.00%。GC-MS检测添加明胶的馒头酯类含量升高40.61%,烷烃类提高48.60%,芳香杂环胺类提高34.03%。α-螺旋含量在面团中有所变化;β-折叠含量在蒸制后馒头中显著增大;β-转角含量均有不同程度的下降(P<0.05),说明添加明胶使蛋白质二级结构中无序的β-转角向有序的β-折叠或α-螺旋结构转换,蛋白质结构更趋于稳定。添加明胶能显著改善馒头的质构特性、感官品质及营养价值。

不同分子量蛋白质对小麦品质及馒头加工品质的影响

为了解不同分子量蛋白质对小麦品质及馒头加工品质的影响,以石优17、石4366、石麦15等30个石麦系列小麦品种为材料,对不同分子量蛋白质相对含量、品质特性以及馒头加工品质进行了检测与分析。结果表明,UPP(SDS不溶性蛋白大聚体)、LPP(大分子量聚合体蛋白)、LMP(大分子量单体蛋白)的相对含量及LPP/LMP比值与小麦粉的大多数品质指标存在显著或极显著相关性;不同分子量蛋白质相对含量较蛋白质含量更能反映小麦品质;UPP相对含量可作为小麦粉品质性状及面筋特性的预测和评价指标。蛋白质含量显著影响馒头的粘着性,UPP、LPP、LMP相对含量及LPP/LMP比值主要影响馒头质构特性中的硬度、胶着性及咀嚼度。UPP相对含量可以作为评估小麦粉是否适宜馒头加工的重要指标。

甘薯生全粉添加量对馒头制作工艺及品质的影响

以甘薯-小麦混粉为原料,探究甘薯生全粉馒头制作配方工艺以及甘薯生全粉添加量对馒头基本成分和物化特性的影响。结果表明,甘薯馒头制作配方最优工艺为甘薯生全粉添加量30%、加水量55%、α-淀粉酶添加量0.02%、普鲁兰酶添加量0.75%,此时甘薯生全粉馒头感官评分最高为84.9。随着甘薯生全粉添加量增加,甘薯馒头淀粉和总膳食纤维含量逐渐增大,蛋白质含量逐渐减小,可溶性糖呈不规律变化趋势且变化幅度较小。随着甘薯生全粉添加量增加,甘薯馒头色度WH值、比容逐渐减小,硬度和胶黏性逐渐增加,黏性、回复性、黏聚性和弹性逐渐减小。随着甘薯生全粉添加量增加,冻藏后复蒸馒头比容逐渐减小,硬度逐渐增大;在相同添加量的情况下,随着冻藏时间的延长,比容呈逐渐减小的变化趋势,硬度呈逐渐增大的变化趋势。综上所述,适当添加甘薯生全粉可制作出品质较好的馒头。

湿热处理对杂豆馒头淀粉消化特性及风味品质的影响

目的研究湿热处理对杂豆馒头消化特性及风味品质的影响。方法选取湿热处理豌豆、红豆、白芸豆3种杂豆制作杂豆馒头,对湿热杂豆馒头的色度、比容、感官评分等进行评价,通过固相微萃取-气相色谱-质谱法(solid phase microextraction-gas chromatography-mass spectrometry,SPME-GC-MS)分析湿热粉杂豆馒头挥发性风味物质变化规律,并对馒头进行体外淀粉消化实验。结果湿热处理杂豆粉的添加降低了馒头的比容,改变了馒头的色度。对豌豆馒头和白芸豆馒头感官评分没有影响,但可显著提高红豆馒头的感官评分(P<0.05)。SPME-GC-MS从湿热杂豆馒头中共检出47种挥发性成分,主要为醛类、醇类、酯类、酮类、芳香族类、烷烃类及杂环类。淀粉体外消化特性表明3种杂豆馒头的抗性淀粉含量显著高于小麦馒头,淀粉水解率低于小麦馒头。结论湿热处理可使杂豆馒头风味品质改善,使红豆馒头和白芸豆馒头抗性淀粉含量提高和淀粉水解率降低,但对豌豆馒头没有影响。研究结果为淀粉基杂豆营养健康食品的加工提供数据支撑。

仿手揉多向压延技术对面团及馒头品质的影响

通过采用流变发酵仪、低场核磁成像分析仪、流变仪、傅里叶红外光谱仪、扫描电子显微镜等分析手段对压延后的面团进行测定,探究在压面5次、15次、25次状态下,传统单向压延与仿手揉多向混合压延处理对面团产生的影响。结果表明,随着压延次数的增加,面团中面筋网络的稳定性整体呈现先升高后降低的趋势,仿手揉多向混合压延处理对面团黏弹流变特性、水分分布特性、发酵特性均有显著性影响,在仿手揉多向压延15次时面团的韧性和发酵特性均呈现最大值,深层结合水含量增加54.05%,微观结构孔洞减少,馒头品质也有显著改善,硬度值显著降低,感官评分也达到最高。通过仿手揉多向压延技术可以减少压延次数,在压延15次后即可使馒头有较好的品质和口感。

酸面团中酵母菌的筛选及其在全麦馒头制作中的应用

为充分挖掘酸面团中优良酵母菌菌种,缓解酸面团因微生物复杂而导致馒头品质不一的问题。以自然发酵的酸面团为研究对象,对酸面团中的酵母菌进行初步筛选及发酵特性研究,并将获取的优良酵母菌应用于全麦馒头的制作。结果发现酸面团中有5株(S1、S2、S3、S4、S5)酵母菌菌株,选出特征明显的S1、S2、S5株菌株进行酵母菌产酒精、繁殖能力及发酵能力研究,分析发现S2和S5产酒精能力最强、S1和S5繁殖能力最强、S2和S5发酵能力最强。通过对3株酵母菌的形态特征及发酵特性的综合评价,确定S5为酸面团中的优势酵母菌。将筛选的优势菌S5与安琪酵母分别添加到全麦面团中,并对2种馒头的外表性质进行测定与感官评定,确定S5发酵的全麦馒头的口感和风味优于安琪酵母全麦馒头。由此可知,S5优势酵母菌对全麦馒头风味物质的积累有显著作用,以期为全麦馒头的品质改良提供有价值的菌种资源和技术参考。

双孢菇粉对面团流变特性及馒头品质的影响

主要研究双孢菇粉不同添加量(5%,10%,15%,20%,25%)对面团流变特性和馒头品质的影响。结果表明,添加量逐渐增大的双孢菇粉于面团中,其吸水率、形成时间、稳定时间和粉质质量指数也呈现增长趋势,面团拉伸特性的各项参数均发生变化。储能模量(G’)和损耗模量(G’’)的数值均有明显的下降趋势,而且G’大于G’’,面团表现出较大的弹性。馒头的比容和L*值均随着菇粉添加量的增加而下降。物性分析结果显示,添加双孢菇粉的馒头硬度较大,黏着性和咀嚼性较强,而弹性、黏聚性、回复性差于未添加的馒头。感官评价表明,双孢菇粉添加量为5%时评分较高。因此,用5%的双孢菇粉代替小麦粉可生产出具有良好感官品质和质量的双孢菇馒头。

基于模糊数学优化银条小米杂粮馒头工艺及体外消化特性分析

为改善我国居民的膳食结构,研制一款品质良好、低淀粉水解指数(Hydrolysis index,HI)和低血糖生成指数(Glycemic index,GI)的银条小米杂粮馒头,以杂粮馒头的外形色泽、组织结构、成品口感及成品风味为评价指标,建立模糊数学感官分析模型,通过单因素试验、质构特性分析及正交试验优化其加工工艺。最终确定银条小米杂粮馒头最佳配制比如下:以小麦粉和小米粉总量(100%)为基准,小米粉添加量35%,银条添加量20%,水添加量40%,酵母添加量1.1%,此条件下的杂粮馒头HI值为58.47,GI值为69.76,微生物及理化指标均符合国家标准。

不同酵母发酵面团特性分析及其对馒头品质的影响

为改善老面馒头的品质,以提高发酵馒头的风味和口感,本研究分析了前期从老面中得到的3株酵母(酿酒酵母XTC-y11、XTC-m13、杰丁塞伯林德纳氏酵母HSO-y3)和一株生产用酵母(CICC 31616)的发酵特性、产香特性及其发酵馒头的感官品质和挥发性风味物质。结果表明,XTC-y11生长的速度最快;XTC-y11、XTC-m13的糖代谢能力较好;与生产用酵母相比,XTC-y11产气量大,XTC-m13面团发酵膨胀体积大,具有良好的发酵能力。HSO-y3在24 h的发酵液中总酯质量浓度最高,达到1.672 g/100 mL。添加老面酵母XTC-y11和XTC-m13的馒头白度、硬度、咀嚼性和弹性最为适中;感官评定的结果中,添加XTC-y11、XTC-m13评分最高。通过气相色谱-离子迁移谱在4个样品中共鉴定出37种风味化合物,其中醇类和酯类物质相对含量较大,XTC-y11中含有较高含量的4-戊烯酸、2-甲基丁醛、(E)-2-己烯酸、乳酸乙酯、乙酸乙酯、2-戊基呋喃;HSO-y3酯类物质含量较高。由偏最小二乘判别分析,发现4种馒头中挥发性成分存在较大差异,并筛选出18种差异化合物。综上所述,XTC-y11其对馒头的风味和品质有积极作用,为提高馒头品质和风味提供有利的参考价值。

预醒发冷冻生胚馒头熟制工艺优化

为提高冷冻生胚馒头的品质,该文探究预醒发时间、解冻方式和蒸制方式对馒头比容、感官评分和质构特性的影响,结合单因素和Box-Behnken响应面法,优化预醒发冷冻生胚馒头熟制工艺。通过差示扫描量热仪、扫描电子显微镜和面包图像分析仪,分析对照生胚面团与最优工艺条件下预醒发冷冻生胚馒头面团可冻结水含量、微观结构以及馒头孔隙分布的变化。结果表明,最佳预醒发冷冻生胚馒头熟制工艺为预醒发时间22 min,醒发箱解冻时间58 min,蒸箱蒸制时间18 min,该条件下馒头具有最优的感官品质,且不发生起泡收缩现象,馒头品质得到明显改善。