Italian lupins: tradition, biodiversity and plant-based nutraceuticals

I Italian lupins are at the center of renewed interest that combines historical tradition, agronomic sustainability e scientific innovation. This legume, deeply rooted in history and in the Italian biodiversity (with ecotypes preserved by custodian farmers), is now re-evaluated for a nutritional profile that goes beyond conventional legumes.

The article analyzes how lupins provide a notable supply of proteins and fibers, but above all how they are an exceptional source of bioactive peptides (with hypoglycemic and antihypertensive properties). Their climate resilience and ability to enrich the soil by fixing nitrogen make them a strategic and sustainable ingredient for the Mediterranean diet and for the supply chains plant-based e gluten-free of the future.

History and popular traditions

The presence of lupin in the Mediterranean basin has been documented since ancient times. Egyptians, Greeks, and Romans appreciated its versatility: nutritious food, protein source for livestock, herbal remedy, and even a ritual symbol (Arnoldi & Greco, 2011). In classical Greece, lupin was considered a staple food for the lower classes and was consumed after prolonged soaking in salt water to eliminate the bitter taste of alkaloids. In theancient Rome the techniques of were perfected debittering for the use of lupins both as food and as green manure, with empirical insight into the plant's ability to fix nitrogen in soils.

In the Middle Ages and until the 20th century, the lupin established itself in Italy, especially in the southern regions, as popular food because it was economical, energetic, and filling. Traditional preparation of lupins required a long soak in running water, followed by preservation in brine, to remove the natural bitterness of the seeds and impart flavor to the product. This mode of consumption, still widespread today, transformed the lupin into an accessible street food, often associated with moments of celebration and social gathering.

The popular traditions also attributed symbolic meanings to the lupin. In some rural areas of Southern Italy, lupins were carried in pockets as a good luck charm or symbol of abundance, while the plant's ability to thrive in low-fertility soils made it a symbol of resilience within farming communities. In regional culinary tradition, beyond consumption in brine, the lupin was used in rustic soups and in poor baking, where the flour was mixed with wheat to enrich bread and fresh pasta with proteins, anticipating by centuries the modern applications in the food industry.

Botanical characterization and seasonality

The genus  Lupinus belongs to the Fabaceae family (like chickpeas, beans, broad beans, and lentils) and includes several species widespread in Italy, among which are  White lupin, Lupinus luteus e Narrow-leaved lupin. The lupin is an annual plant with deep roots that establish a symbiosis with nitrogen-fixing bacteria, thereby helping to improve soil fertility. The leaves are palmate, the flowers white or yellow depending on the species, and the pod contains oval seeds which, in traditional Italian varieties, can reach significant sizes.

The cultivation cycle varies depending on the climate. Sowing usually takes place in autumn or spring, with flowering between April and June and harvest between late June and August. Consumption can occur throughout the year thanks to the availability of the product in brine or dried, while fresh lupins are linked to the summer season.

Terroir, agronomic practices and sustainability

Lupin cultivation in Italy is mainly rooted in Sicily, Puglia, Calabria, Basilicata, Campania, Lazio, Molise, Abruzzo and Marche, regions where the plant has found a natural adaptation to sandy or slightly acidic soils and hot-arid climates. Italy is home to a remarkable biodiversity lupin fields, with local ecotypes selected over the centuries to resist drought, reduce bitter alkaloid content and ensure large seeds particularly suitable for processing. Varieties such as the ancient Sicilian types or Apennine lupins today represent a genetic heritage of great value, subject to cataloging, recovery and conservation by universities, research centers and networks of custodian farmers.

Lupin agronomy is naturally oriented towards sustainability. The ability to fix nitrogen significantly reduces the need for chemical fertilizers, contributing to the reduction of agriculture's environmental impact. The low water requirement and robustness to difficult pedoclimatic conditions make it particularly suitable for organic farming. Furthermore, the inclusion of lupin in crop rotations with cereals helps to improve soil fertility, limiting the spread of pathogens and enriching agricultural biodiversity. Conservation programs for native varieties, particularly in Southern Italy, today aim to preserve this genetic wealth, also enhancing it as a resource for climate resilience (Lucas et al., 2015).

Nutritional properties and health benefits

Nutritional composition

Lupins are among the legumes richest in proteins: the protein content can exceed 40% of dry weight, with a profile of amino acids particularly useful for high biological value food formulations (Lucas et al., 2015). The main proteins are represented by albumins and globulins, present in a 1:9 ratio, where globulins constitute about 90% of the total protein content. The main globulin fractions include vicilins and legumins (α-conglutin and β-conglutin) and the minor proteins γ-conglutin and δ-conglutin, each with specific functional properties (Villarino et al., 2022).

The fibers average 15-20% in whole seeds, with some studies reporting values up to 30-50% in dehulled seeds, most of which is represented by insoluble fiber (Raya-Pérez et al., 2022). The fats, accounting for 9-12%, are mostly mono- and polyunsaturated, with a favorable ratio between omega-3 and omega-6 of about 1:2, particularly beneficial for cardiovascular health (Arnoldi & Greco, 2011). The content of minerals - including calcium, potassium, magnesium, iron, phosphorus and zinc - and vitamins of the B group (folates), vitamin E and tocopherols further enrich the nutritional profile (Raya-Pérez et al., 2022).

Cardiovascular benefits

From a physiological point of view, lupins can help improve cardiovascular health thanks to favorable effects on plasma lipids. Clinical studies have indicated that regular consumption of foods enriched with lupin proteins is associated with a significant reduction of cholesterol total and LDL cholesterol (Belski et al., 2011). Proposed mechanisms include increased expression of LDL receptors and reduced activity of genes involved in cholesterol biosynthesis (Parolini et al., 2012).

A recent systematic review highlighted that lupin consumption may promote beneficial effects on blood pressure, blood lipids, insulin sensitivity, and gut microbiota (Bryant et al., 2022). Lupin fiber, in particular, has shown the ability to bind bile acids, increasing their fecal excretion and thus reducing circulating cholesterol levels (Fechner et al., 2014).

Glycemic control and metabolic function

Lupin proteins show hypoglycemic properties noteworthy. Gamma-conglutin, in particular, has demonstrated the ability to enhance the activity of insulin and metformin on cellular glucose consumption, suggesting a potential use in glycemic control (de Sandoval-Muñiz et al., 2018). Fibers exert a modulating effect on postprandial glycemia thanks to the low glycemic index of lupin and the ability to slow carbohydrate absorption (Arnoldi & Greco, 2011).

Clinical studies have reported that lupin-enriched foods can improve insulin sensitivity and glycemic control in overweight individuals and patients with type 2 diabetes (Ward et al., 2020). Quinolizidine alkaloids present in small amounts in 'sweet' varieties, particularly lupanine, can also enhance insulin release, contributing to hypoglycemic effects (Raya-Pérez et al., 2022).

Bioactive peptides and functional properties

Lupin proteins represent an exceptional source of bioactive peptides which are released during enzymatic digestion or fermentation. These peptides have demonstrated multiple biological activities, including antioxidant, anti-inflammatory, immunomodulatory, hypolipidemic, hypoglycemic, antihypertensive, osteoprotective, and neuroprotective properties (Chakrabarti et al., 2021).

Peptides derived from lupin have shown excellent in vitro antioxidant capacities, with activity neutralizing DPPH, ABTS, and hydroxyl radicals, as well as iron-chelating properties (Kamran et al., 2023). The inhibitory activity of angiotensin-converting enzyme (ACE) has been widely documented, with specific peptides showing potential antihypertensive effects comparable to those of synthetic drugs (Fadimu et al., 2022).

A particularly innovative aspect concerns deflamin, a polypeptide oligomer found in white lupin, which has demonstrated in animal models the ability to inhibit matrix metalloproteinases (MMP), particularly MMP-9, with reduction ofintestinal inflammation associated with colitis, suggesting potential applications in the treatment of inflammatory bowel diseases (Mota et al., 2022).

Other possible health benefits

Thenatural absence of gluten makes lupins suitable also for people with celiac disease or gluten intolerance. The content of L-arginine, a precursor of nitric oxide, can contribute to the vasodilatory effect and beneficial effects on blood pressure (Arnoldi & Greco, 2011).

The presence of prebiotic oligosaccharides, such as raffinose and stachyose, can promote the growth of beneficial bacteria in the gut microbiota, contributing to digestive health. The polyphenols, the carotenoids and tocopherols present in the seeds exert antioxidant and protective effects against oxidative stress (Raya-Pérez et al., 2022).

Traditional and innovative uses

Traditional uses

In Italian tradition, lupins are mainly consumed in brine, as a snack or appetizer, and in some local preparations like rustic soups. Lupin flour, widely used in rural baking, was utilized to enrich the dough with proteins and provide structure.

Innovative applications in the food industry

In recent years, lupins have gained an important role in innovative products and functional foods thanks to their nutritional properties, meeting the growing demand for plant proteins and gluten-free foods.

Gluten-free pasta and baked goods. Both debittered lupin intermediate products through fermentation and lupin flour can be used to improve the protein profile of gluten-free pasta, baked goods, and baking mixes. The incorporation of lupin flour in varying amounts from 10 to 30% allows a significant increase in protein and fiber content while simultaneously reducing carbohydrates.

Technological properties. Lupin proteins demonstrate excellent emulsifying, gelling, foaming, and water retention capacities, making them ideal for a wide range of applications (Duranti et al., 2008). Their water absorption capacity and protein binding properties are particularly useful in formulating high-protein baked products.

Plant-based meat substitutes. The high protein concentration and the ability to confer structure to doughs make lupin a strategic ingredient in the production of plant-based meat substitutes. Studies have shown that it is possible to reduce the fat content in meat-based products by up to 37% by replacing it with lupin fiber, while maintaining acceptable sensory characteristics (Archer et al., 2004).

Plant-based beverages and alternatives to dairy products. Lupin proteins are used in the formulation of plant-based beverages, plant-based alternatives to yogurt and cheeses, exploiting their emulsifying properties and the ability to form stable gels.

Functional and nutraceutical products. Lupin protein hydrolysates and isolated bioactive peptides find application in the nutraceutical industry and dietary supplements for their multifunctional biological activity. Protein concentrates enriched with deflamin have been proposed as functional additives for foods intended for people with inflammatory bowel diseases (Mota et al., 2022).

Protein snacks and sports products. Lupin flour and flakes are incorporated into protein bars, breakfast cereals, granolas, and high-protein snacks intended for the sports and wellness market.

Emerging applications. Research is exploring the use of lupin peptides in the formation of self-assembling hydrogels with antioxidant properties, opening prospects for the development of bio-inspired nano-nutraceuticals and functional materials (Pugliese et al., 2021).

Tips for foodies and importers

For gastronomy enthusiasts, it is advisable to choose organic Italian lupins, to support supply chains more committed to environmental and health protection. Choosing products with lower salt content can improve the consumption experience.

For importers of Made in Italy food products, it is essential to evaluate suppliers who guarantee traceability and organic certification. Italian varieties offer strong appeal in gourmet markets and can provide added value in gluten-free and high-protein formulations. It is important to verify that the content of quinolizidine alkaloids complies with international safety thresholds (≤ 0.2 g/kg DM for sweet varieties).

The team of GIFT – Great Italian Food Trade, thanks to its technical and regulatory experience in Italian agri-food supply chains, can support international buyers in identifying reliable suppliers and verifying product compliance with European and international standards.

Conclusions

Italian lupins represent a virtuous meeting between tradition, biodiversity, sustainability agronomic and innovation food. From the Street Food most popular up to modern products plant-based, lupin continues to be a valuable ingredient for the Mediterranean diet and a strategic ally for the transition to more sustainable food systems. The richness of native varieties and Italy's role in their conservation make this legume not only a healthy food but also an agricultural resource of great value for the future. Scientific evidence accumulated in recent years confirms the potential of lupins and their derivatives as functional ingredients for the development of innovative foods with proven benefits for human health.

Dario Dongo

Credit cover Farm La Pira by La Pira Corrado (Canicattini Bagni, Siracusa)

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