Effect of temperature and some added compounds on the stability of blood orange marmalade

Jams and marmalades are often wrongly believed to be stable products, as the degradation of pigments such as anthocyanins, browning reactions, and the formation of sugar degradation products may occur during storage. Thepaper aims at studying some of the degradation reactions occurring in blood orange marmalade stored at 20 .C and35 .C. The addition of natural (tea extract) and naturally occurring (ascorbic acid, cysteine, gallic acid) compounds to marmalade was addressed at investigating the possible effect on retarding such phenomena. Results highlight the dependence of anthocyans and 5-hydroxymethyl-2-furaldehyde (HMF) levels on the storage temperature. Marmaladesadded with cysteine, unlike the samples added with phenol compounds, showed higher anthocyans and lower HMF levels just after processing, together with a reduced anthocyan loss kinetics and a slowdown of HMF formation during storage at both temperatures.