Effects of palm oil quality and packaging on the storage stability of dry vegetable bouillon paste

Vegetable bouillon paste, prepared by dry-mixing of pre-produced dry ingredients with addition of semisolid palm oil, was stored at the slightly elevated temperature of 40 °C for up to 12 weeks for comparing modified atmosphere packaging (MAP; oxygen concentration initially below 0.5%) packaging with free availability of oxygen in order to identify the mechanisms leading to quality degradation. An increased browning and increased formation of volatile compounds related to Maillard reactions and oxidation of secondary lipid oxidation products were observed for the vegetable bouillon paste stored without limiting the oxygen availability. The use of palm oil (kept liquid by heating to 50 °C for one week) was further found to promote quality degradation as compared to fresh palm oil when the availability of oxygen was not limited by the packaging of the vegetable bouillon paste. For modified atmosphere packaging, the effect of the quality of the oil on storage stability of the product was less pronounced.