PLANT MINERAL FERTILIZATION AFFECTING HEART-OF-PALM PROCESSING

Brazil is the main producer and exporter of canned heart-of-palm or palmito; a product widely consumed in more than 60 countries. Most of the production is based on the exploitation of natural resources. However, this condition has changed lately with the development of peach palm (Bactris gasipaes Kunth) plantations for the same purpose. Nonetheless, old habits, such as processing with poor practices, have been continued, increasing the risk for human health. Heart-of-palm is a low-acid food, needing correct acidification during processing in order to avoid the development of Clostridium botulinum exotoxins. In the present paper, heart-of-palm harvested from a field fractional factorial N, P, K fertilization trial was utilized to demonstrate that mineral fertilization plays an important role in heart-of-palm safety processing. Heart-of-palm initial pH ranged from 5.51 to 6.59, with a significant positive linear response to N fertilization (0 to 400 kg ha^-1 year^-1 of N). The amount of citric acid required to keep the processed product pH at 4.3 (safety pH), showed a wide between-plant variation, ranging from 0.34 to 1.34 g of acid per 100 g of fresh heart-of-palm, with a highly significant linear negative response to increasing K doses (0 to 200 kg ha^-1 year^-1 of K₂O). The wide range in the amount of citric acid to be added to fresh heart-of-palm highlights the importance of a rigid control of acidification in the processing industries, since palmitos are processed from different species, grown in different climatic and edaphic regions and from plants submitted to diverse fertilization rates and schedules.