Emerging rapid and non-destructive techniques for quality and safety evaluation of cacao: recent advances, challenges, and future trends

Cacao is one of the world's most highly sought-after agricultural commodities for its great nutritional and economic importance. The cacao's quality is an essential parameter to consider during postharvest processes to satisfy consumers' preferences and commercial acceptability. However, the quality and safety evaluation of cacao is mostly monitored using human inspection, which is arduous because it requires more effort and offers inaccurate results, as human judgment is subjective. Furthermore, the conventional method for quality evaluation, such as cut-test and chromatographic analysis, is destructive in nature, resulting in the disposal of samples after the measurement is carried out. To overcome the drawbacks and challenges offered by conventional methods, the rapid and non-destructive technique was introduced. This study focuses on the application of emerging rapid and non-destructive approaches that have been used to monitor the quality and safety of cacao, notably during the harvesting, grading/sorting, fermentation, and postharvest processes. It includes imaging-based computer vision, spectroscopic-based techniques, hyperspectral imaging techniques, and other non-destructive techniques. Non-destructive techniques can evaluate the different internal and external quality parameters of cacao, such as maturity index, fermentation index, moisture content, total fat content, pH, total phenolic compounds, and others. This review also highlighted the advantages, drawbacks, and future perspectives of rapid and non-invasive techniques for evaluating the quality of cacao beans. This current work has proven the effectiveness of rapid and non-invasive in replacing the conventional methods for evaluating the quality of cacao.