Food Safety in Rice-Based Beverages: Labeling Screening and LAB-Driven Metal(loid) Detoxification Review

Introduction and aims:

The Spanish plant-based beverage sector represents 66% of market value. Rice (Oryza sativa) represents a strategic raw material tailored to specific dietary needs, including celiacs, lactose-intolerant individuals, athletes, and "veggie" populations. However, its natural accumulation of Cd and i-As poses a critical food safety threat under European regulation (EU) 2023/915. While Lactic Acid Bacteria (LAB) fermentation offers nutritional advantages, current research on rice-based beverages overlooks heavy metal remediation. This study aimed to evaluate the labeling of commercial rice beverages in Spain and, through a literature review, assess the biotechnological potential of LAB starter cultures to reduce metal(oid) bioavailability and modulate arsenic speciation.

Methods: A market screening of 342 plant-based references (295 beverages and 47 fermented alternatives) was conducted. Inclusion criteria required: (1) availability in Spanish online supermarkets, and (2) accessible ingredient lists and mandatory nutritional labelling. Concurrently, a literature review analysed LAB-mediated fermentation of rice beverages and their metal(loid) levels, evaluating starter cultures as a biotechnological strategy to enhance safety.

Results and Discussion: Market analysis revealed cereals lead the beverage category (57%), with rice constituting 32%. Conversely, a major void exists in the fermented segment: soy (83%) and nuts (17%) dominate, whereas cereals are residual (2%), with absence of fermented rice alternatives. Regarding safety, scientific evidence confirms specific LAB strains (mainly Lactobacillus) effectively sequester Cd, Pb, Ni, and methylmercury through cell-wall binding, offering a strategic pathway to alter arsenic speciation toward less toxic forms. Consequently, this lack of fermented rice products in Spain represents a significant technological and market opportunity.

Conclusion: Implementing tailored LAB fermentation serves as a novel dual-purpose industrial strategy: it drives innovation by diversifying the functional food market while enhancing food safety through biotechnological mitigation of dietary toxicological risks.