Role of tailored sourdough fermentation in the flavor of wholegrain-oat bread.

Sourdough technology has been known for its role in the improvement of texture, flavor, and quality of mainly wheat and rye-based breads for decades. However, little is reported about its use in the improvement of whole-grain oat bread, especially concerning flavor formation, which is one major consumer drivers. This study investigated the effects of sourdough obtained by different lactic acid bacteria and yeast starters consortia on the texture and flavor of 100% oat bread. Four different consortia were selected to obtain four oat sourdoughs, which were analyzed to assess the main features due to the different starter fermentation metabolism. Sourdoughs were added to breads as 30% dough weight. Bread quality was technologically monitored via hardness and volume measurements. Sourdough breads were softer and had higher specific volume. The sensory profile of sourdoughs and breads was assessed by a trained panel in sensory laboratory conditions, and the volatile profile was analyzed by HS-SPME-GC-MS. Sourdoughs were rated with higher intensities than untreated control for most of attributes, especially concerning sour aroma and flavor attributes. Sourdough breads were rated with higher intensities than control bread for sour vinegar flavor and total odor intensity, in addition they had richer volatile profile. Our results confirmed that sourdough addition can lead to an enhanced flavor, moreover, it demonstrated that the use of different consortia of lactic acid bacteria and yeast strains leads to the improvement of texture and altered sensory profile of whole-oat bread.

B Vitamins in Legume Ingredients and Their Retention in High Moisture Extrusion.

Legumes have been recognised as healthy and environmentally friendly protein sources. Knowledge about the vitamin B contents in legume ingredients and extrudates is scarce. In this study, we investigated thiamin, riboflavin, niacin, and folate in various faba bean, lupin, and pea ingredients. Further, the retention of B vitamins in high moisture extrusion was studied. Prior to liquid chromatographic determinations of thiamin, riboflavin, niacin, and folate, vitamins were extracted by acid hydrolysis (niacin), enzymatic treatment (folate), or their combination (thiamin and riboflavin). The contents (on a dry matter basis) varied greatly among different ingredients: the thiamin content was 0.2-14.2 µg/g; riboflavin, 0.3-5.9 µg/g; niacin, 8.8-35.5 µg/g, and folate, 45-1453 ng/g. Generally, the highest levels were in flours and protein concentrates, whereas low levels were observed in isolates. The retention of B vitamins was excellent in high moisture extrusion, except for folate in faba bean, where the folate contents were 42-67% lower in the extrudates than in the respective ingredient mixtures. In terms of both vitamin B contents and their retention, extrudates containing substantial amounts of flour or protein concentrate are promising plant-based sources of thiamin, riboflavin, niacin, and folate.

The flavor of faba bean ingredients and extrudates: Chemical and sensory properties.

Faba bean, processed into ingredients (flour, protein concentrate, protein isolate), can be extruded to meat alternatives with a fibrous texture. Despite its importance for consumer acceptance, not enough is known about the flavor of faba bean ingredients nor about the chemical and sensory changes caused by high-moisture extrusion. Therefore, the aim of this work was to describe the flavor of faba bean ingredients and the corresponding extrudates and to understand how their composition affects the perception of sensory attributes. Firstly, faba bean protein ingredients and extrudates were characterized for lipid-degrading enzymatic activities, flavor precursors, and volatile and non-volatile flavor-active compounds. Secondly, sensory profiling was conducted. Thirdly, partial least squares regression was applied to understand the relationship between chemical and sensory data. This study showed that faba bean protein concentrate had the strongest taste and aftertaste (respectively 7 and 6, on a 0-10 intensity scale), bitterness (6-7), and pea flavor and odor (respectively 6 and 5), whereas faba bean protein isolate had the strongest cereal flavor (4) and odor (4), and off-flavor (2) and off-odor (3). Faba bean flour had the mildest flavor. High-moisture extrusion brought several chemical changes to the ingredients, including the formation of several volatile compounds and inactivation of lipid-degrading enzymes. Only traces of tannins were found in extrudates. The presence of free phenolics, vicine, and convicine was linked to strong taste and aftertaste, bitterness, and a drying sensation of the mouth, whereas lipid oxidation products were related to pea, cereal, and off-odors and flavors.

Fermentation Conditions Affect the Synthesis of Volatile Compounds, Dextran, and Organic Acids by Weissella confusa A16 in Faba Bean Protein Concentrate.

Fermentation with Weissella confusa A16 could improve the flavor of various plant-based sources. However, less is known about the influence of fermentation conditions on the profile of volatile compounds, dextran synthesis and acidity. The present work investigates the synthesis of potential flavor-active volatile compounds, dextran, acetic acid, and lactic acid, as well as the changes in viscosity, pH, and total titratable acidity, during fermentation of faba bean protein concentrate with W. confusa A16. A Response Surface Methodology was applied to study the effect of time, temperature, dough yield, and inoculum ratio on the aforementioned responses. Twenty-nine fermentations were carried out using a Central Composite Face design. A total of 39 volatile organic compounds were identified: 2 organic acids, 7 alcohols, 8 aldehydes, 2 alkanes, 12 esters, 3 ketones, 2 aromatic compounds, and 3 terpenes. Long fermentation time and high temperature caused the formation of ethanol and ethyl acetate and the reduction of hexanal, among other compounds linked to the beany flavor. Levels of dextran, acetic acid, and lactic acid increased with increasing temperature, time, and dough yield. Optimal points set for increased dextran and reduced acidity were found at low temperatures and high dough yield. Such conditions would result in hexanal, ethyl acetate and ethanol having a relative peak area of 35.9%, 7.4%, and 4.9%, respectively.

Flavor challenges in extruded plant-based meat alternatives: A review.

Demand for plant-based meat alternatives has increased in recent years due to concerns about health, ethics, the environment, and animal welfare. Nevertheless, the market share of plant-based meat alternatives must increase significantly if they are to support sustainable food production and consumption. Flavor is an important limiting factor of the acceptability and marketability of plant-based meat alternatives. Undesirable chemosensory perceptions, such as a beany flavor, bitter taste, and astringency, are often associated with plant proteins and products that use them. This study reviewed 276 articles to answer the following five research questions: (1) What are the volatile and nonvolatile compounds responsible for off-flavors? (2) What are the mechanisms by which these flavor compounds are generated? (3) What is the influence of thermal extrusion cooking (the primary structuring technique to transform plant proteins into fibrous products that resemble meat in texture) on the flavor characteristics of plant proteins? (4) What techniques are used in measuring the flavor properties of plant-based proteins and products? (5) What strategies can be used to reduce off-flavors and improve the sensory appeal of plant-based meat alternatives? This article comprehensively discusses, for the first time, the flavor issues of plant-based meat alternatives and the technologies available to improve flavor and, ultimately, acceptability.

Italian consumers' attitudes towards entomophagy: Influence of human factors and properties of insects and insect-based food.

Studies on consumers' perceptions towards entomophagy have recently gained popularity. However, the use of the general term "insect" represents a limitation of previous research, due to the need for more precise terminology. This study assessed attitudes towards specific insects, their gastronomic preparations, their relationships with human factors and the characteristics of insects as a food source. Using a survey, socio-demographics, personality traits, willingness to eat (WTE) six edible insects and their relative insect-based products or dishes (IBPD) and the emotions associated with entomophagy were collected from 400 Italians. Compared with females, males were found to be more positive towards insects, less influenced by the species and level of processing of insects and more willing to eat insects for reasons of taste. Eating insects evoked adventurous, daring and wild emotions, while disgust and food neophobia represented the main factors in refusal to eat insects. WTE was: crickets > bee larvae and grasshoppers > mealworms and silkworms > giant water bugs. A similar result was obtained considering the respective IBPD. On average, adult insects were preferred over larvae. Three subject groups, namely "In favour of eating insects" (41%), "Picky towards eating insects" (32%) and "Against eating insects" (27%) were found. A sensory evaluation performed on three cricket-based samples with 52 Italians revealed that a low level of insect visibility was preferred. This study gives new insights into the variables related to the acceptance of entomophagy by determining the characteristics of a potential consumer and of a probable insect product for the market.