Lipid and volatile profiles of Finnish oat batches of pure cultivars: Effect of storage on the volatile formation.

Recent data showing the compositional variation and storage behavior among different oat batches for the purpose of food remains limited. Lipids of twenty oat flour samples of pure cultivars grown in Finland during 2019 were extracted and fractionated into neutral and polar-rich lipids. Flour was stored for nine months, and profiles of volatiles and tocols were analyzed to reveal oxidative stability. The lipid content was 5.9-8.9 g per 100 g of flour [DW] and consisted of 78.7 ± 2.5 % neutral and 21.3 ± 2.5 % polar lipids. Palmitic (16 %), oleic (36 %), and linoleic (39 %) acids were the most abundant fatty acids. Neutral lipids had more oleic and less linoleic and palmitic acids than polar lipids. The fresh samples correlated with tocols, pentanal, 2-pentylfuran, 2-heptanone, nonanal, 2-butanone, and heptanal, while stored samples were associated with 3-octen-2-one, 2-octenal, hexanal, and octanal. Lipid composition and oxidative stability are essential factors for selecting oat batches for food applications.

How food matrices modulate folate bioaccessibility: A comprehensive overview of recent advances and challenges.

The incomplete absorption of dietary folate makes it crucial to understand how food matrices affect folate bioaccessibility. Bioavailability encompasses bioaccessibility, which depicts the proportion that is liberated from the food matrix during digestion and becomes available for absorption. Bioavailability studies are expensive and difficult to control, whereas bioaccessibility studies utilize in vitro digestion models to parameterize the complex digestion, allowing the evaluation of the effect of food matrices on bioaccessibility. This review covers the folate contents in various food matrices, the methods used to determine and the factors affecting folate bioaccessibility, and the advances and challenges in understanding how food matrices affect folate bioaccessibility. The methods for determining bioaccessibility have been improved in the last decade. Current research shows that food matrices modulate folate bioaccessibility by affecting the liberation and stability of folate during digestion but do not provide enough information about folate and food component interactions at the molecular level. In addition, information on folate interconversion and degradation during digestion is scant, hindering our understanding of the impact of food matrices on folate stability. Moreover, the role of conjugase inhibitors should not be neglected when evaluating the nutritional value of food folates. Due to the complexity of food digestion, holistic methods should be applied to investigate bioaccessibility. By synthesizing the current state of knowledge on this topic, this review highlights the lack of in-depth understanding of the mechanisms of how food matrices modulate folate bioaccessibility and provides insights into potential strategies for accurate evaluation of the nutritional value of dietary folate.

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.

Polysaccharides as wall materials in spray-dried microencapsulation of bioactive compounds: Physicochemical properties and characterization.

Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.

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.

5-Methyltetrahydrofolate Is a Crucial Factor in Determining the Bioaccessibility of Folate in Bread.

This study investigated the bioaccessibility of folate in wheat bread baked with different ingredients and processing methods. Next, different matrices were spiked with 5-methyltetrahydrofolate, gallic acid (GA), or both to investigate the stability of 5-methyltetrahydrofolate during in vitro digestion. The folate bioaccessibility in bread varied from 44 to 96%. The inclusion of whole-grain or faba bean flour significantly improved both folate content and bioaccessibility. Baking with yeast increased the folate content by 145% in bread but decreased folate bioaccessibility compared to the bread without added yeast because of the instability of 5-methyltetrahydrofolate. Spiking experiments confirmed oxidation as a critical reason for 5-methyltetrahydrofolate loss during digestion. However, GA protected this vitamer from degradation. Additionally, 5-methyltetrahydrofolate was less stable in whole-grain wheat matrices than other matrices. This study demonstrated that the stability of 5-methyltetrahydrofolate is crucial for folate bioaccessibility in bread, and methods for stabilizing this vitamer should be further studied.

Physical Properties of Extrudates with Fibrous Structures Made of Faba Bean Protein Ingredients Using High Moisture Extrusion.

Faba bean is a potential ingredient due to its high protein yield and its possible cultivation in colder climate regions. In this study, meat analogues made from faba bean protein isolate (FPI) and concentrate (FPC) blends were produced using high moisture extrusion. The aim of this study was to investigate the effect of the FPI content (FPIc), feed water content (FWC), and temperature of the long cooling die (LT) during extrusion on the mechanical and physicochemical properties as well as on the structure of the meat analogues. Increased FPIc resulted in higher values in hardness, gumminess, chewiness, and cutting strengths as well as in darker colour and decreased water absorption capacity. The effect of increased FWC on these properties was weaker and the opposite. Images from microtomography revealed that higher FPIc led to a less organised fibrous structure. In conclusion, fibrous structures can be achieved by utilising a mixture of faba bean protein ingredients, and a higher FPC content seemed to promote fibre formation in the meat analogue.

Variation in the Content and Composition of Tocols in a Wheat Population.

Wheat is a well-known source of B vitamins but also contains significant amounts of vitamin E and related tocols, which have a number of positive health benefits. However, there are no reports on increasing the tocol content of wheat. A prerequisite for increasing the tocol content is the identification of variation in its amount within wheat and related cereals. We therefore determined the tocol content and composition in the grain of 230 recombinant inbred lines (RILs) of a diverse biparental wheat population (Mv Toborzó/Tommi), showing variation in the total content from 13.69 to 45.18 µg/g d.m. The total content also showed transgressive segregation in the population. The effect of the genotype on the variance components of tocols was studied, and the broad-sense heritability was calculated to be 0.71. The lines were also grouped based on their tocol content and analyzed for their chemical composition and breadmaking quality. The high heritability value and the wide variation found in the total amount indicate that increasing the content of tocols is a possible breeding strategy.

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.

Millennials' Consumption of and Attitudes toward Meat and Plant-Based Meat Alternatives by Consumer Segment in Finland.

Millennials are considered the key generation with regard to the consumption of plant-based meat alternatives via flexitarianism. This study sought to characterize millennials' consumer segments based on their consumption of and attitudes toward meat and meat alternatives. We conducted an online survey on the hedonic tones of the associations evoked by meat and meat alternatives, consumption of such foods, and diet-related attitudes among a representative sample of Finnish millennials (N = 546, 59% women, age 20-39 years). Some 41% of respondents regularly ate plant-based meat alternatives, while 43% had tried such foods. We divided the respondents into six segments based on the hedonic tones of their meat vs. meat alternatives associations. The segments differed in terms of their consumption of meat alternatives and the underlying reasons why, importance of meat in meals, and Meat Commitment Scale scores. The segment that reported much more positive associations with meat than meat alternatives (~14% of the respondents) may prove resistant to interventions intended to reduce meat intake, whereas the segment that displayed the most positive attitudes toward meat alternatives (~18%) did not eat much meat. Thus, the four middle segments (totaling ~68%), whose associations' hedonic tones were close to each other, may be the best targets for future interventions designed to reduce meat consumption through the use of meat alternatives. To conclude, introducing a simple segmentation allowed us to identify consumer segments with large potential to reduce meat consumption.

The bioaccessibility of folate in breads and the stability of folate vitamers during in vitro digestion.

Both the liberation and stability of endogenous folate are relevant to the bioaccessibility of folate. Since folates are unstable, in addition to studying the natural folate content in foods, bioaccessibility should be considered. To understand folate changes during digestion, a mixture of standard folate compounds was subjected to a static in vitro gastrointestinal digestion assay. Next, different types of bread were analysed to study how food matrices influence folate bioaccessibility. Folates were identified and quantitated by a UHPLC-PDA/FL method. Folic acid and 10-formylfolic acid were stable throughout the digestion, and the conversions among formyl folates and 5,10-methenyltetrahydrofolate were triggered at the gastric phase. Tetrahydrofolate began to degrade during the oral phase and was lost completely during the gastric phase. During the intestinal phase, 5-methyltetrahydrofolate began to degrade and suffered a 60% loss. With bread matrices, folate conversions and the decrease of reduced folates were also common, but the extent of changes varied. Generally, rye breads had the highest (80-120%) bioaccessibility of folate, while oat breads had the lowest (31-102%). The high proportion of 5-methyltetrahydrofolate could result in low bioaccessibility because of its relatively low stability during digestion in bread matrices. An increase in 10-formylfolic acid content was observed for all the breads, but 10-formyldihydrofolate seemed to be more stable in rye breads than in oat and wheat breads. The results showed that folates undergo significant changes during digestion and that food matrices could be modified to affect these changes towards better folate bioaccessibility.

Bioaccessibility of vitamin B12 synthesized by Propionibacterium freudenreichii and from products made with fermented wheat bran extract.

The bioaccessibility of vitamin B12 (B12) in plant-based products fortified using wheat bran extract fermented with B12-producing food-grade Propionibacterium freudenreichii was studied by applying a standard static in vitro model. At first, a culture of P. freudenreichii, fresh or heat-treated, was subjected to in vitro assays. Then, food ingredients or products were evaluated for their in vitro bioaccessibility: spray-dried wheat bran extract powder, pasta made with an extruder using fermented bran extract and breads made with spray-dried powder or with added cyanocobalamin. B12 bioaccessibility from the fresh P. freudenreichii culture was only ca. 53%, which, when heated, increased to 73%. The bioaccessibility of B12 from the food products varied from 75% (spray-dried powder) to 95% (breads). B12 from the fortified bread was as bioaccessible as from the bread made with added cyanocobalamin (99%). The in vitro results suggest that B12 synthesized by P. freudenreichii, when fortified in the studied cereal-based products, is largely bioaccessible and could be available for absorption. Plant-based products fortified using fermentation with P. freudenreichii could thus be considered excellent sources of bioaccessible B12.

Bioaccessibility of folate in faba bean, oat, rye and wheat matrices.

Cereals and legumes are rich in folate. However, due to the instability of folate, processing and digestion can induce significant folate loss. In this paper, folate bioaccessibility of faba bean, oat, rye and wheat flours and pastes was studied using a static in vitro digestion model. Folate bioaccessibility depended on food matrices, varying from 42% to 67% in flours and from 40% to 123% in pastes. Digestion was associated with the interconversion of formyl folates, as well as the increase of oxidised vitamers and decrease of reduced vitamers. Especially in faba bean, 5-methyltetrahydrofolate showed surprisingly good stability both in digestion and heat treatment, resulting in high bioaccessibility. The physiological concentration of ascorbic acid did not stabilise folate in digestion; however, a higher level helped to maintain reduced vitamers. Heat treatment (10-min paste making) could improve folate bioaccessibility by liberating folate from the food matrices and by altering folate vitamer distribution.

Relationship of Compositional, Mechanical, and Textural Properties of Gluten-Free Pasta Using Different Quinoa (Chenopodium quinoa) Varieties.

Quinoa epitomizes the drive for healthier foods with ethnic concepts in developed countries, particularly among millennials. As a result, the popularity of quinoa as a gluten-free alternative has steadily grown over the last 20 years. Despite this, little is known about the impact of specific varieties on processed foods. The purpose of this study was to examine the impact of quinoa varieties (variety and content) on the mechanical and textural properties of buckwheat-based extruded pasta (spaghetti). Peruvian native (var. rosada taraco, kuchivila, negra collana, and mistura) and Latvian-grown (var. titicaca) varieties were independently incorporated to pasta between 5 and 20% (w/w). Pasta containing 20% quinoa var. negra collana, which presented the largest content of fiber and lowest content of saponin, was strongly associated to structural resilience (i.e., cohesiveness, firmness). Conversely, pasta containing 20% quinoa var. Titicaca appeared structurally weak (i.e., smooth). The addition of saponin-containing varieties to pasta (20%), such as rosada taraco and mistura, resulted in resilient structures with little effect on taste (incl. bitterness). Despite initial stability, pasta containing 20% quinoa var. kuchivila suffered heavy structural damage. In conclusion, the relationship of compositional, mechanical, and textural properties of pasta was strongly variety-dependent.

Potential of faba bean lipase and lipoxygenase to promote formation of volatile lipid oxidation products in food models.

Faba bean can respond to the need for plant-based proteins for human consumption. The aim of this work was to study the role of lipid-modifying enzymes in faba bean in causing off-flavour compounds during processing. The faba bean exhibited high lipase and lipoxygenase (LOX) activities, with pH optima being 8.0 and 6.0, respectively. Faba bean LOX preferred free fatty acids (FFAs) over triacylglycerols as substrates, and together with other LOX pathway enzymes, it formed specific volatile products, as measured using headspace solid-phase microextraction-gas chromatography. During the preparation of the food models (i.e. the extracts and emulsions), enzymatic lipid oxidation occurred. The inclusion in the emulsions of rapeseed oil, especially of rapeseed oil FFAs, remarkably increased the amounts of volatile products. The largest quantities of products were formed in food models at pH 6.4, which is close to the pH optimum of LOX. Further studies on lipase in food models are needed.

Red-Brown Pigmentation of Acidipropionibacterium jensenii Is Tied to Haemolytic Activity and cyl-Like Gene Cluster.

The novel Acidipropionibacterium genus encompasses species of industrial importance but also those associated with food spoilage. In particular, Acidipropionibacterium acidipropionici, Acidipropionibacterium thoenii, and Acidipropionibacterium jensenii play an important role in food fermentation, as biopreservatives, or as potential probiotics. Notably, A. jensenii and A. thoenii can cause brown spot defects in Swiss-type cheeses, which have been tied to the rhamnolipid pigment granadaene. In the pathogenic bacterium Streptococcus agalactiae, production of granadaene depends on the presence of a cyl gene cluster, an important virulence factor linked with haemolytic activity. Here, we show that the production of granadaene in pigmented Acidipropionibacterium, including A. jensenii, A. thoenii, and Acidipropionibacterium virtanenii, is tied to haemolytic activity and the presence of a cyl-like gene cluster. Furthermore, we propose a PCR-based test, which allows pinpointing acidipropionibacteria with the cyl-like gene cluster. Finally, we present the first two whole genome sequence analyses of the A. jensenii strains as well as testing phenotypic characteristics important for industrial applications. In conclusion, the present study sheds light on potential risks associated with the presence of pigmented Acidipropionibacterium strains in food fermentation. In addition, the results presented here provide ground for development of a quick and simple diagnostic test instrumental in avoiding potential negative effects of Acidipropionibacterium strains with haemolytic activity on food quality.

Co-fermentation of Propionibacterium freudenreichii and Lactobacillus brevis in Wheat Bran for in situ Production of Vitamin B12.

The present study investigated the effect of co-fermentation on vitamin B12 content and microbiological composition of wheat bran. Propionibacterium freudenreichii DSM 20271 was used as the producer of vitamin while Lactobacillus brevis ATCC 14869 was selected to ensure the microbial safety of the bran dough. Fermentation trials were conducted in bioreactors to monitor and adjust the pH of the ferments. Vitamin B12 level reached 357 ± 8 ng/g dry weight (dw) after 1 day of pH-controlled fermentation with P. freudenreichii monoculture and remained stable thereafter. In co-fermentation with L. brevis, slightly less vitamin B12 (255 ± 31 ng/g dw) was produced in 1 day and an effective inhibition of the growth of total Enterobacteriaceae and Bacillus cereus was obtained. On day 3, vitamin B12 content in pH-controlled co-fermentation increased to 332 ± 44 ng/g dw. On the other hand, without a pH control, co-fermentation resulted in a stronger inhibition of Enterobacteriaceae and B. cereus but a lower level of vitamin B12 (183 ± 5 ng/g dw on day 3). These results demonstrated that wheat bran fermented by P. freudenreichii and L. brevis can be a promising way to produce vitamin B12 fortified plant-origin food ingredients, which could reduce cereal waste streams and contribute to a more resilient food chain.

Epoxy and hydroxy fatty acids as non-volatile lipid oxidation products in oat.

The aim of the study was to investigate the occurrence and formation of peroxygenase catalysed non-volatile oxidised fatty acids (NVOFAs), especially epoxy and hydroxy fatty acids, which potentially provide off-flavours in oat. A method based on extraction of NVOFAs using accelerated solvent extraction and analysis by UHPLC-ELSD/MS was developed. Hydroxy and epoxy fatty acids from oleic and linoleic acids were present as major NVOFAs in non-heat treated (NHT) oat products, and the contents increased markedly during storage. In a controlled storage experiment, NVOFA contents in NHT oat flours increased to 1700-2000 µg/g, whereas in heat-treated samples, only to 200-400 µg/g. Epoxy fatty acids seemed to be the first products that occurred, followed by hydroxy fatty acids and minor NVOFAs. The formation of NVOFAs was related to lipase catalysed lipid hydrolysis and the formation of volatile lipid oxidation products. Inactivation of lipid degrading enzymes is crucial to producing stable oat products.

Acidipropionibacterium virtanenii sp. nov., isolated from malted barley.

A Gram-stain-positive, catalase-positive and pleomorphic rod organism was isolated from malted barley in Finland, classified initially by partial 16S rRNA gene sequencing and originally deposited in the VTT Culture Collection as a strain of Propionibacterium acidipropionici (currently Acidipropionibacterium acidipropionici). The subsequent comparison of the whole 16S rRNA gene with other representatives of the genus Acidipropionibacterium revealed that the strain belongs to a novel species, most closely related to Acidipropionibacterium microaerophilum and Acidipropionibacterium acidipropionici, with similarity values of 98.46 and 98.31 %, respectively. The whole genome sequencing using PacBio RS II platform allowed further comparison of the genome with all of the other DNA sequences available for the type strains of the Acidipropionibacterium species. Those comparisons revealed the highest similarity of strain JS278T to A. acidipropionici, which was confirmed by the average nucleotide identity analysis. The genome of strain JS278T is intermediate in size compared to the A. acidipropionici and Acidipropionibacterium jensenii at 3 432 872 bp, the G+C content is 68.4 mol%. The strain fermented a wide range of carbon sources, and produced propionic acid as the major fermentation product. Besides its poor ability to grow at 37 °C and positive catalase reaction, the observed phenotype was almost indistinguishable from those of A. acidipropionici and A. jensenii. Based on our findings, we conclude that the organism represents a novel member of the genus Acidipropionibacterium, for which we propose the name Acidipropionibacteriumvirtanenii sp. nov. The type strain is JS278T (=VTT E-113202T=DSM 106790T).

Protein-lipid co-oxidation in emulsions stabilized by microwave-treated and conventional thermal-treated faba bean proteins.

The course of protein-lipid co-oxidation was investigated in oil-in-water emulsions stabilized with proteins extracted from microwave-treated (MWT) and conventional thermal-treated (CTT) faba beans stored at 37°C for 7 days. Emulsions prepared with proteins from untreated (UT) faba beans and soy protein isolate (SP) were monitored for comparison. Lipid oxidation was detected through formation of primary and secondary oxidation products while protein oxidation was examined via tryptophan fluorescence degradation in interface and aqueous phase. Oxidation of proteins was more emphasized in the interfacial layers of MWT, CTT, and SP emulsions than in UT emulsions due to the prominence of radical chain-driven co-oxidation mechanism while lipoxygenase (LOX) activity in UT and MWT emulsions resulted in high amounts of hydroperoxides and abundance in lipid oxidation volatiles. Conventional thermal treatment provided better oxidative stability than microwave treatment reflected in lower levels of hydroperoxides and relative lack of diversity in lipid volatiles. Among detected volatiles, formation of ketones was more distinguished in MWT, CTT, and SP emulsions while UT emulsions contained a more diverse range of alkenals and alkanals. Ketones are known to form mainly through radical recombination reactions which combined with the results of protein oxidation supports that radical transfer reactions between proteins and lipids were the driving force behind oxidation in MWT, CTT, and SP emulsions. Treatments of faba beans resulted in increased oxidative stability of emulsified lipids and lower degradation of aqueous phase proteins.