Discrimination of volatiles of refined and whole wheat bread containing red and white wheat bran using an electronic nose

Evaluation of Flours from Ancient Varieties of Wheat (Einkorn, Emmer, Spelt) used in Production of Bread

The study investigates rheological properties of dough and baking process made from flour obtained by milling grains from ancient varieties of wheat (einkorn, emmer and spelt), compared to common wheat flour dough (Arkadia variety). The findings show that einkorn flour dough and emmer flour dough present poor tolerance to mechanical processing and prolonged fermentation. These types of dough should be mixed through relatively short, and fermentation time should not exceed 80 minutes for einkorn dough and 45 minutes in the case of emmer dough. In the case of spelt flour dough, the optimum duration of mechanical processing and fermentation amounted to 10 minutes and 60 minutes, respectively. In terms of technological and baking parameters, spelt flour was most similar to the flour obtained by milling conventional wheat, and the superiority of the former was in fact identified in the case of selected factors. A one-stage method was used in the baking process and the bread was then subjected to organoleptic and physicochemical assessments and to texture profile analysis (TPA). Measurements were also performed to determine the indicators reflecting the quality of the baking processes, including dough yield, baking loss and bread yield. The physical parameters of the bread produced were significantly related to the wheat variety. The loaves made from einkorn and spelt flour were of good quality, comparable to the bread made from the conventional wheat, while their baking quality indicators were satisfying. Bread dough made from emmer flour did not meet the required parameters mainly related to the organoleptic assessment and selected physical properties of the bread crumb. However, the one-stage production method should not be applied to doughs made from emmer flour. Given the specific characteristics of the breads produced from the ancient wheat varieties, including their pleasant taste and aroma, as well as attractive colour in the case of einkorn bread, these baked products may be an interesting addition to the assortment of breads on offer from bakeries, restaurants and agritourist farms.

Effect of Supplementation of Flour with Fruit Fiber on the Volatile Compound Profile in Bread

This paper presents the analyses of the effect of fiber additives on volatile organic compounds in bread. The bread was baked from wheat flour with the addition of 3% of fruit fiber, following common procedures. After baking, volatile organic compounds contained in the control bread and breads supplemented with cranberry, apple, and chokeberry fiber were determined. The SPME/GC-MS technique was used for the identification of the odor profile, and the electronic nose Agrinose (e-nose) was used to assess the intensity of the aroma. The results of the analyses revealed the profile of volatile organic compounds in each experimental variant, which was correlated with responses of the electronic nose. The results indicate that the volatile compound profile depends on the bread additives used and influences the intensity of bread aroma. Moreover, the profile of volatile organic compounds in terms of their amount and type, as well as the intensity of their interaction with the active surface of the electrochemical sensors, was specific exclusively for the additive in each case.

Characterization of the key aroma compounds in three types of bagels by means of the sensomics approach

Background

To evaluate the impact of cold fermentation time on bagel rolls, the key aroma-active compounds in the volatile fractions obtained from three different bagel rolls through solvent assisted flavor evaporation (SAFE) were sequentially characterized by an aroma extract dilution analysis (AEDA), quantified by stable isotope dilution and analyzed by odor activity values (OAVs) respectively.

Results

Findings revealed 40 aroma-active compounds with flavor dilution (FD) factor ranges of 2–1024. Of these, 22 compounds (FD ≥ 16) were quantified by stable isotope dilution assays (SIDA). Subsequent analysis of the 22 compounds by odor activity values (OAVs) revealed 14 compounds with OAVs ≥ 1 and the highest concentrations were obtained for 2,3-butanedione, 2-phenylethanol, 3-methylbutanal and acetoin respectively. Two recombination models of the bagels (i.e. 24 h and 48 h bagels) showed similarity to the corresponding bagels. Omission tests confirmed that 2,3-butanedione (buttery), acetoin (buttery), 2-acetyl-1-pyrroline (roasty), 5-methyl-2-furanmethanol (bread-like), (Z)-4-heptenal (biscuit-like) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone, were the key aroma compounds. Additionally, acetic acid, butanoic acid, 2-phenylethanol (honey-like), 3-methylbutanoic acid, 2/3-methylbutanal, vanillin, 3-methylbutanol, methional were also important odorants of the bagel.

Conclusion

Whilst the long, cold fermented bagels exhibited roasty, malty, buttery, baked potato-like, smoky and biscuit-like notes, the control bagels produced similar but less intense odor notes.

Review of the Sensory and Physico-Chemical Properties of Red and White Wheat: Which Makes the Best Whole Grain?

Establishing sensory and physico-chemical differences between products made from red and white wheat may guide the choice of wheat for use in whole grain and high fibre products. As sensory acceptance is key to consumption, this scoping review aimed to document sensory and physico-chemical research demonstrating quantitative differences in red and white wheat and the associated bran. The following databases were systematically searched following the PRISMA protocol: PubMed, Medline, Scopus, CINHAL and ScienceDirect (1990–2019). Of 16 studies, 13 were sensory studies with 529 participants (six of which included quantitative analysis) and three additional quantitative studies. Overall, 10 studies were in favour of white wheat (seven sensory studies, two focused on quantitative analysis and two with additional quantitative studies). Whole grain (wholemeal) bread, pita bread, crackers, noodles, tortillas, flour, intact grains and bran were examined. Aside from the seed coat colour, levels of bound versus free phenolic compounds and polyphenol oxidase activity appeared most responsible for the differences in red and white wheat. Ensuring the sample size for sensory studies are large enough to detect between-group preferences and linking to physico-chemical analysis are recommended. Attention to blinding techniques in sensory testing and use of food products realistically and consistently prepared with commercial potential are also suggested. This scoping review provides confidence in preference for white wheat for whole grain products, particularly for breads, tortillas and in the choice of white wheat for products suitable for the Asian market.

Metabolomic approach to study the impact of flour type and fermentation process on volatile profile of bakery products

Metabolomic approaches applied to fermented foods are at the state of the science and represent a robust and reliable approach to identify, quantify and characterise the biochemical profiles of raw materials and transformed products. The outcomes so far obtained are cornerstones to understand mainly nutritional and sensorial inherent features. Formulations of new bakery products with increased nutritional values is trending the market, but sensorial attributes still need to be improved to reach a wider audience. The present work describes the application of gas chromatography-mass spectrometry (GC-MS) and electronic nose analyses, to investigate over the volatilome of different bakery products, obtained from mature and immature grains (KAMUT® khorasan and durum wheat) and transformed by a sourdough made of Lactobacillus spp. and Saccharomyces cerevisiae. From the recipient results has emerged that the sensors used can distinguish the KAMUT® khorasan doughs fermented industrially at the fully ripe stage, the same doughs at the milky stage and KAMUT® khorasan sourdough at the fully ripe stage. Electronic nose allowed discriminating between different types of flours and GC-MS indicated the volatilome of sourdough KAMUT® khorasan case as the most promising. Thus, the combination of different independent variables in the bread process to improve the sensorial quality of the product, when is backed by metabolomics, represents an effective approach to study, characterise and exploit the sensorial quality of breads.

Analytical methods for volatile compounds in wheat bread

Bread aroma is one of the main requirements for its acceptance by consumers, since it is one of the first attributes perceived. Sensory analysis, crucial to be correlated with human perception, presents limitations and needs to be complemented with instrumental analysis. Gas chromatography coupled to mass spectrometry is usually selected as the technique to determine bread volatile compounds, although proton-transfer reaction mass spectrometry begins also to be used to monitor aroma processes. Solvent extraction, supercritical fluid extraction and headspace analysis are the main options for the sample treatment. The present review focuses on the different sample treatments and instrumental alternatives reported in the literature to analyse volatile compounds in wheat bread, providing advantages and limitations. Usual parameters employed in these analytical methods are also described.