Heat Treatment, Cultivar and Formulation Modify the Sensory Properties and Consumer Acceptability of Gels Containing Faba Bean (Vicia faba L. minor) Protein Concentrates

Metabolite variations in faba bean ingredients: Unraveling the links between off-flavors and chemical compounds

Faba bean ingredients are attracting interest for their suitability in producing protein-rich plant-based foods. However, their sensory characteristics (e.g., bitterness) challenge consumer acceptance. This study explored variations in the metabolome and the links between metabolites and sensory attributes using UHPLC-qTOF-MS/MS analysis of faba bean flour, two protein concentrates, and protein isolate. Partial Least Squares regression identified metabolites contributing to sensory descriptors, and it was validated against the VirtuousMultiTaste platform. Genetic variation and processing methods contributed to the metabolite composition of faba bean ingredients. We annotated 115 compounds with choline and vicine having the highest relative abundance. Five clusters suggested cultivar-specificity and process-related differences. Several compounds were linked to bitterness and mouth-drying orosensation, including caprolactam, gingerglycolipid, lysine, and vicine. Some compounds were reported as potentially bitter for the first time. This study lays the foundation for further research on the bitterness of these compounds and receptor-level investigations for targeted flavor optimization.

Postharvest Physiology and Handling of Guava Fruit

Guavas are typical tropical fruit with high nutritional and commercial value. Because of their thin skin and high metabolic rate, guavas are highly susceptible to water loss, physical damage, and spoilage, severely limiting their shelf-life. Guavas can typically only be stored for approximately one week at room temperature, making transportation, storage, and handling difficult, resulting in low profit margins in the industry. This review focuses on the physiological and biochemical changes and their molecular mechanisms which occur in postharvest guavas, and summarizes the various management strategies for extending the shelf-life of these sensitive fruits by means of physical and chemical preservation and their combinations. This review also suggests future directions and reference ideas for the development of safe and efficient shelf-life extension techniques.

Sensory properties of thickened tomato soup enhanced with different sources of protein (whey, soy, hemp, and pea)

Thickened soup formulations were created with different proteins (hemp, soy, pea, and whey) to improve protein and fluid intake. The formulations consisted of a control soup, and soups with 6% whey protein, 6% hemp protein, 6% pea protein, and 6% soy protein by volume. The suitability of the samples for those living with dysphagia was evaluated using the international dysphagia diet standardization initiative (IDDSI) spoon tilt test and a sensory trial (51 older adults and 51 younger adults). The sensory trial used nine-point hedonic scales and check-all-that-apply to evaluate the different formulations. The sample with the whey addition was not significantly different than the control in terms of liking of flavor and texture, but it decreased the participants' overall liking. The hemp, pea, and soy decreased overall liking as well as liking of flavor and texture. They were associated with off-flavors, aftertaste, and astringency. The responses from the older and younger adults were compared and significant differences were found in their liking of the texture, with the older adults finding the formulations' texture significantly more acceptable. Overall, the study identified that hemp, pea, and soy did not create acceptable thickened soup formulations and the hemp and pea formulations did not achieve a consistency level that is acceptable for those living with dysphagia.

Faba Bean (Vicia faba L. minor) Bitterness: An Untargeted Metabolomic Approach to Highlight the Impact of the Non-Volatile Fraction

In the context of climate change, faba beans are an interesting alternative to animal proteins but are characterised by off-notes and bitterness that decrease consumer acceptability. However, research on pulse bitterness is often limited to soybeans and peas. This study aimed to highlight potential bitter non-volatile compounds in faba beans. First, the bitterness of flours and air-classified fractions (starch and protein) of three faba bean cultivars was evaluated by a trained panel. The fractions from the high-alkaloid cultivars and the protein fractions exhibited higher bitter intensity. Second, an untargeted metabolomic approach using ultra-high-performance liquid chromatography-diode array detector-tandem-high resolution mass spectrometry (UHPLC-DAD-HRMS) was correlated with the bitter perception of the fractions. Third, 42 tentatively identified non-volatile compounds were associated with faba bean bitterness by correlated sensory and metabolomic data. These compounds mainly belonged to different chemical classes such as alkaloids, amino acids, phenolic compounds, organic acids, and terpenoids. This research provided a better understanding of the molecules responsible for bitterness in faba beans and the impact of cultivar and air-classification on the bitter content. The bitter character of these highlighted compounds needs to be confirmed by sensory and/or cellular analyses to identify removal or masking strategies.

Activation of bitter taste receptors by saponins and alkaloids identified in faba beans (Vicia faba L. minor)

Despite their interests, faba beans are characterised by bitterness but little is known about its compounds that activate the 25 human bitter receptors (TAS2Rs). This study aimed to determine the bitter molecules in faba beans, especially saponins and alkaloids. These molecules were quantified by UHPLC-HRMS in flour, starch and protein fractions of 3 faba bean cultivars. The fractions from the low-alkaloid cultivar and the protein fractions exhibited higher saponin content. Vicine and convicine were highly correlated with bitter perception. The bitterness of soyasaponin βb and alkaloids was studied using a cellular approach. Soyasaponin βb activated 11 TAS2Rs, including TAS2R42 whereas vicine activated only TAS2R16. The high vicine content should explain the faba bean bitterness considering that concentration of soyasaponin βb was low. This research provides a better understanding of the bitter molecules in faba beans. Selection of low-alkaloid ingredients or alkaloid removal treatments could improve the faba bean flavour.

Non-Volatile Compounds Involved in Bitterness and Astringency of Pulses: A Review

Despite the many advantages of pulses, they are characterised by off-flavours that limit their consumption. Off-notes, bitterness and astringency contribute to negative perceptions of pulses. Several hypotheses have assumed that non-volatile compounds, including saponins, phenolic compounds, and alkaloids, are responsible for pulse bitterness and astringency. This review aims to provide an overview highlighting the non-volatile compounds identified in pulses and their bitter and/or astringent characteristics to suggest their potential involvement in pulse off-flavours. Sensorial analyses are mainly used to describe the bitterness and astringency of molecules. However, in vitro cellular assays have shown the activation of bitter taste receptors by many phenolic compounds, suggesting their potential involvement in pulse bitterness. A better knowledge of the non-volatile compounds involved in the off-flavours should enable the creation of efficient strategies to limit their impact on overall perception and increase consumer acceptability.

Origins of volatile compounds and identification of odour-active compounds in air-classified fractions of faba bean (Vicia faba L. minor)

Faba bean (Vicia faba L. minor) has many interests but is characterised by off-notes (negative odours/aromas) due to volatile compounds that are promoted during seed processing. Little is known about the volatile compounds of faba bean and their contribution to its odour. The purpose of this study was to determine the volatile compound origins of air-classified fractions (flour (F), starch (S) and protein (P)) from 3 faba bean cultivars and identify the odour-active compounds. Firstly, the volatile content of the fractions was extracted by solvent-assisted flavour evaporation (SAFE) and analysed by gas chromatography-mass spectrometry (GC-MS). A total of 147 volatile compounds were detected and categorised into 12 chemical classes. The P fractions had many volatile compounds from free fatty acid (FFA) oxidation and a higher lipoxygenase (LOX) activity. The volatile content suggested that cultivar 1 (C1) was confronted with a biotic stress at field whereas cultivar 2 (C2), richer in molecules from amino acid (AA) degradation, was contaminated by microorganisms in the field. Secondly, 35 odour-active compounds (OACs) were identified by GC-olfactometry (GC-O) and 12 odour-classes were used to describe the faba bean odours. The P fractions had higher detection frequency (DF) than the S and F fractions. P2 had a more complex odour profile due to important FFA and AA degradation. This work provides a better understanding of the impact of cultivar and processing steps on the faba bean volatile content. Selection of pulse-based ingredients with low volatile compounds could improve their flavour and increase their consumption.