Banana and apple extracts with efficient microorganisms and their effect on cadmium reduction in cocoa beans (Theobroma cacao L.)

Abstract

This research was aimed to assess the impact of efficient microorganisms and fruit extracts (Banana and Apple) on fermentation of cacao collected in Ecuador. The work was focused on compliance with European Union regulation 2021/1323, which sets cadmium (Cd) limits at 0.80 mg kg^–1 for cocoa products that are exported. The study conducted experiments on cacao of two Ecuadorian provinces, Manabí and Esmeraldas, employing two types of bioinoculants (Biol Albiobatch and EM-1 20%). Bioinoculants were analyzed for their potential in the reduction of Cd, using a Trifactorial statistical design (Completely randomized trifactorial design, CRTD) 2 × 2 × 2 added + 2. Ten treatments with three replicates were used, including two unamended controls. The Rohan Modified micro-fermentation method was employed, considering various parameters such as cacao fruit morphology, temperature, pH, and °Brix. After fermentation, the cocoa beans were sun-dried to reduce moisture content, and their fermentative state was assessed. Cd levels were determined using the USDAP 3050B method. The results showed that different treatments affected cacao fruit morphology, temperature, pH, and Brix differently. Notably, the Biol EM-1 + Banana treatment of cacao of Manabí exhibited the most favorable results in several aspects. The cutting test revealed significant improvements in fermentation quality for this treatment. Moreover, the use of microorganisms resulted in a substantial reduction in Cd levels, with cacao of Esmeraldas and Manabí provinces experiencing reductions of 63.25% and 58.20%, respectively. Overall, this research demonstrates the potential of efficient microorganisms and fruit extracts to enhance cocoa fermentation and reduce Cd content, contributing to the quality and compliance of Ecuador cocoa exports with EU regulations.