As the popularity of plant-protein diets continues to rise, so does the recognition of the environmental impact associated with some of the most commonly consumed plant proteins, such as soy. Irresponsible production of soy is a leading contributor to deforestation and the loss of biodiversity in the Amazon. Considering that most of the soy on the global market is grown in Brazil, the European Union serves as a significant importer. Although a majority of this soy is utilized for animal feed, the demand for plant protein in food production is steadily increasing.
In contrast, lupin beans are a protein crop known for their seed protein content, which can rival that of soybeans, reaching levels of up to 44%. Additionally, lupin beans have greater tolerance to various environmental stresses compared to other legumes. Similar to other legumes, lupin beans can also help to improve soil health. However, lupin seeds contain naturally occurring bitter and toxic alkaloids, making them unappealing to consumers. Although sweet white lupin cultivars have been developed worldwide through domestication, the specific genes responsible for this desirable “sweetness” have remained uncertain.
In a groundbreaking achievement, a team of researchers from Europe and the UK has finally identified the specific gene responsible for the sweetness in lupin. The researchers confirmed that the most common sweet gene in white lupin, known as “pauper,” encodes an acetyltransferase (AT) enzyme involved in the early quinolizidine alkaloid (QA) pathway. The researchers discovered that a single-nucleotide polymorphism (SNP) in the pauper plants significantly impairs the activity of the AT enzyme, leading to a blockage in the QA pathway. To validate their hypothesis, the team replicated the sweetness trait in narrow-leafed lupin through mutagenesis.
With the identification of the sweet gene in lupin, the researchers anticipate that this discovery will contribute to the breeding of lupin and facilitate the domestication of other legumes containing bitter QA compounds. Approximately 300 other lupin species also accumulate QAs and hold great potential as crop candidates once these bitter compounds are removed. Notably, non-GMO techniques used in this study offer an attractive solution for legume crop candidates that lack transformation protocols or are grown in regions with restrictive GMO legislation.
Australia currently accounts for 85% of global lupin production, presenting significant opportunities for the legume. The Grains & Legumes Nutrition Council in Australia believes that lupins, if their bitter taste and textural issues are addressed, can become a powerful protein source in the plant-based ingredient market. In addition to their high protein content, lupins are rich in fiber, containing approximately 27g per 100g. This fiber content is twice that of most other legumes, making lupins a valuable nutritional resource. Furthermore, lupins contribute to soil health as nitrogen-fixing plants.
In summary, the identification of the lupin sweet gene has opened new possibilities for lupin breeding and the domestication of other legumes. This breakthrough holds promise for the food and beverage industry in terms of creating products that align with consumer trends and demands for sustainable and innovative solutions. Moreover, this research showcases the importance of adhering to regulations and considering packaging and marketing strategies within the food and beverage sector. To stay ahead in this industry, businesses must remain aware of current trends in food and beverage, food manufacturing, food processing technology, food distribution, and food and drink consumer preferences. By incorporating such knowledge, companies can drive growth and success in a highly competitive marketplace.
Source: Science Advances, ‘The causal mutation leading to sweetness in modern white lupin cultivars’; Published 4 August 2023; DOI: 10.1126/sciadv.adg8866; Authors: Davide Mancinotti, Katarzyna Czepiel, Jemma L. Taylor, Fernando Geu-Flores.
