PHYSICO-CHEMICAL CHARACTERIZATION OF THE FORAGE PALM PEEL FOR POTENTIAL APPLICATION IN THE FOOD INDUSTRY

Food analysis is an essential requirement to verify the quality and applicability of raw materials and the identity of products. Opuntia ficus-indica (L.) Mill is an economically important cactus used as food, highly perishable but with the potential for technological transformation into flour through the dehydration process, which can be used to formulate new products. This study aimed to analyze the physicochemical characteristics of forage palm peel flour (FPPF) for future application in biotechnological processes. To do this, the forage palm peel was subjected to cutting and oven drying at 105°C for 3 hours, followed by grinding in a ball mill and sieving to obtain the flour. The determined physicochemical characteristics included moisture, ash, proteins, lipids, soluble and insoluble lignin, cellulose, hemicellulose, instrumental color, pH, total titratable acidity (TTA), water activity (aw), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The results indicate stable flour concerning moisture (8.76%) and aw (0.441). Furthermore, FPPF showed a high ash content (18.01%), protein content of 7.03%, lipids of 2.79%, pH of 4.37 and TTA of 4.98% (in citric acid). Regarding dietary fibers, a high content of hemicellulose (31.42%) and cellulose (12.80%) was observed, with low levels of soluble lignin (1.55%) and insoluble lignin (1.68%). The flour exhibited a relatively dark hue (L*=57.3), with a yellowish (b*=24.52) and slightly reddish (a*=4.44) ton, characterized by the degradation of chlorophyll and predominance of carotenoids and flavonoids, respectively. Prominent peaks in the FTIR were observed at 3200cm-1 (free water), 1600cm-1 (conjugated alkenes - unsaturated fatty acids), and 1100cm-1 (secondary CO group - phytochemicals, fatty acids, and proteins). In the SEM image, polyhedral fragments of the microstructure with various sizes were observed, along with characteristic lamellae of plant material. The identified characteristics confirm the nutritional potential of cactus flour for use in the food industry.