From Waste to Taste: Transforming Carob Pulp into Sustainable Chocolate Alternatives

Carob pulp, a by-product of carob processing, is typically discarded after seed extraction for locust bean gum (LBG) production. However, its composition and sensory properties make it a sustainable alternative to cocoa, offering similar flavor attributes with a significantly lower environmental impact. As a drought-resistant Mediterranean leguminous plant, carob (Ceratonia siliqua) requires fewer resources for cultivation compared to cocoa, presenting an opportunity to transform food waste into value-added products in the confectionery industry. Despite its potential, few studies have characterized the volatile profile of roasted carob pulp, which is crucial for its application as a cocoa substitute. In this study fermentation and alkalization are explored as strategies to enhance the sensory properties of carob pulp powder. Samples were fermented with different microorganisms or alkalized and subsequently roasted at 120°C and 150°C. Currently, we are analysing the volatile organic compound (VOC) profiles of roasted carob powders by solid phase microextraction coupled to gas chromatography–mass spectrometry (SPME/GC-MS) and comparing them to cocoa powder as a reference. The SPME/GC-MS method was optimized for carob volatilome analysis before to start the screening of the experimental samples. An untargeted approach was employed to monitor, among the others, the key odorants in carob powder samples. The impact of roasting temperature and fermentation processes or alkalinization on VOC composition will be evaluated. The carob powders with a volatile organic profile most similar to cocoa powder will be used to produce chocolate prototypes which will then be subjected to sensory analysis to identify the best-performing variants in the final product. The aim of the study is to demonstrate the feasibility of carob pulp powder as a value-added ingredient in chocolate alternatives, supporting food waste valorization.