Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres Characterisation of the volatile flavour compounds in low and high tannin faba beans (Vicia faba var. minor) grown in Alberta, Canada Rami Akkad a , Ereddad Kharraz a , Jay Han b , James D. House c , Jonathan M. Curtis a, ⁎ a Lipid Chemistry Group, Department of Agricultural, Food and Nutrition Sciences, University of Alberta, Edmonton, Alberta, Canada b Food Processing Development Centre, Alberta Agriculture and Forestry, Leduc, Alberta, Canada c Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada ARTICLE INFO Keywords: Volatiles Off-flavours Pulse flour HS-SPME GC-MS ABSTRACT The volatile flavour profiles of Canadian-grown faba beans (Vicia faba var. minor) were evaluated by headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–mass spectrometry (GC-MS). Two low- and high-tannin varieties were chosen, each in the form of dehulled and whole seed flours (DLT, DHT, WLT, and WHT, respectively). Pre-incubation time, fibre-extraction time, extraction temperature, and sample amount were evaluated during method optimization. The volatiles identified were classified into nine groups: aromatic hy- drocarbons, aldehydes, alkanes, alkenes, alcohols, ketones, organic acids, esters, and others. Significant differ- ences between dehulled and whole samples were found. Volatiles derived from amino acids were consistently observed in the volatile profile of all types. Despite the low lipid content of faba bean, significant amounts of volatiles normally associated with unsaturated fatty acids were present. HS-SPME/GC-MS proved to be a rapid, effective, and reproducible method (typical RSD < 5%) suitable for routine evaluation of faba bean volatile flavours. 1. Introduction Many types of pulses are taking an increasingly important role in both human and animal nutrition. Among these, faba beans have a high content of nutrients including protein, vitamins, minerals, and fibre, so are highly recommended as an alternative food by health organizations and dieticians (Oomah, Patras, Rawson, Singh, & Compos-Vega, 2011). Faba beans also have strong agronomic characteristics, achieving the highest atmospheric nitrogen fixation among annual pulse crops in North America (Walley, Clayton, Miller, Carr, & Lafond, 2007). This can increase the overall fertility of the soil and reduce the need for ni- trogenous fertilizers. However, despite these well-recognized nutri- tional and agronomic benefits, the faba bean is underused in some re- gions of the world. One of the reasons for this is its distinctive beany flavour. The volatile and non-volatile flavours of pulses can be affected by many factors associated with the crop including cultivar, year, and location (Azarnia et al., 2011). In addition, food processing conditions affect flavour (Murat, Bard, Dhalleine, & Cayot, 2013); for instance it has been noted that after baking faba bean flour, some of the undesir- able aromas may be replaced by a bitter taste (Hinchcliffe, McDaniel, Vaisey, & Eskin, 1977). Pulses are easy-to-store due to their low water content, but on the other hand, storage conditions, such as temperature and relative hu- midity can affect some of their physical and chemical properties. For example, a significant color darkening of faba bean, accompanied by seed hardening and tannin reduction, was observed during storage (Nasar-Abbas et al., 2008). Since faba bean hull generates a stronger flavour after cooking, dehulling may improve the flavour of the raw flour (Jiang et al., 2016). Moreover, certain beany flavours which are thought to be produced by the action of endogenous peroxidase and lipoxygenase enzymes, can be eliminated by the thermal pre-treatment of faba beans. Tannins are anti-nutritive compounds affecting the palatability and digestion in monogastric animals (Jansman, Huisman, & van der Poel, 1993). A consequence of the presence of condensed tannins in the seed coats is a reduction in protein solubility, and the inhibition of digestive enzyme activities (Griffiths, 1984). Therefore, only low-tannin types of faba beans, often referred to as “zero tannin”, are suitable for both human and animal consumption. Regular faba beans contain up to 8–9% tannins, resulting in some of their perceived bitterness. Off-fla- vours in pulses have also been correlated to the presence of saponins, phenolic compounds and alkaloids, in addition to many volatile com- pounds (Roland, Pouvreau, Curran, van de Velde, & de Kok, 2017). Faba bean contains low amounts of fat (up to 3%) in the form of https://doi.org/10.1016/j.foodres.2019.02.044 Received 4 December 2018; Received in revised form 16 February 2019; Accepted 23 February 2019 ⁎ Corresponding author. E-mail address: jcurtis1@ualberta.ca (J.M. Curtis). Food Research International 120 (2019) 285–294 Available online 26 February 2019 0963-9969/ © 2019 Published by Elsevier Ltd. T