Plant-Based
Approaches to address off-flavour challenges associated with plant proteins
Off-flavors associated with plant proteins are a significant challenge for the plant-based smart protein sector, affecting consumer acceptance. Various intrinsic (crop-related) and extrinsic (processing-induced) factors are responsible for these undesirable flavours.
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Plant-Based
- Raw materials, ingredients, and inputs
- Ingredient optimisation
Resources
For more information, please see the following resources:
- Dr. Jian Li is taking the beany flavor out of plant proteins
- Identification of beany off- flavor in pea proteins
- Surmounting the off-flavor challenge in plant-based foods
- Mitigating off-flavors of plant-based proteins
- Insights into formation, detection and removal of the beany flavor in soybean protein
- Plant protein flavor chemistry fundamentals and techniques to mitigate undesirable flavors
Previous GFI-funded research related to this topic:
Current challenges
Flavour (= aroma + taste) is one of the key parameters that determine the consumer preference for any food product. The applications of plant-based proteins in meat, dairy, and egg alternatives are mainly hindered by the presence of off-flavours that impact consumer acceptance. The above limitation is attributed to the beany and grassy flavours, bitter and chalky taste, astringency, and a strong aftertaste associated with plant-based proteins (Sha & Xiong, 2022). Generally, aldehydes, ketones, and short-chain alcohols are the constituents that lead to these off-flavours by the following mechanisms:
- Beany and grassy notes: Common in soybean and pea proteins, these flavours are primarily due to aldehydes, ketones, and alcohols. Specifically, soybean proteins are known for their strong beany flavour. Lipoxygenase activity in soybeans causes the formation of volatile compounds such as hexanal and pentanal, leading to the beany flavour.
- Bitter and astringent tastes: These are often associated with pulses and oilseeds, resulting from compounds such as saponins and phenolics.
The off-flavours in plant proteins vary with plant cultivars and the method of protein extraction. It might be generated during protein extraction, food processing, and storage (Tao et al., 2022). Identifying and mitigating these off-flavours is crucial for improving the sensory appeal and marketability of plant-based protein products. While physical, chemical and biological approaches such as thermal treatment, extrusion, solvent extraction, fermentation and enzymatic hydrolysis are employed to reduce off-flavours, these methods can affect the functional properties of proteins.
Proposed solutions
The plausible strategies to tackle off-flavours associated with plant proteins could be upstream (at the crop level) or downstream (processing interventions). The former approach can focus on genetic, agronomic, and biochemical approaches to reducing off-flavour precursors in plant proteins. The latter category of solutions could aim at eliminating or neutralising off-flavours and creating new flavours during the appropriate step of processing after crop harvest and protein extraction.
Successful proposals can focus on the following aspects:
- Breeding of low off-flavour genotypes of crops
- Development of artificial intelligence (AI)-based models for the creation of flavours and flavour precursors that can be used in plant-based meat and egg alternatives
- Designing encapsulation approaches using appropriate carrier materials (ex. Starch, gum Arabica, ꞵ-cyclodetxtrin) and drying techniques (ex. spray drying) to mask the undesirable flavours of plant-based proteins
- In-process flavor generation by utilising a sample of deodorized plant protein as the matrix for recombining desirable flavour precursors that mimic the volatile compounds generated during different conditions of cooking used for animal-derived products (shallow frying, deep frying, grilling, boiling, sautéing)
- Creation of novel bitterness-blocking agents that are preferably derived from natural sources and tailored to address the off-flavour challenges associated with plant-based proteins.
- Conjugating plant proteins with excipients (ex. gum Arabica) through controlled Maillard reactions or natural flavours (ex. Umami compounds)