The fluorescence assay for Maillard product accumulation does not correlate with seed viability

Abstract

AbstractA recent hypothesis states that the accumulation of amino-carbonyl reaction products of reducing sugars with proteins (Maillard products) is related to the loss of seed vigour and viability during ageing. Since Maillard products are biochemical end products, their accumulation should provide an index of seed deterioration. A simple fluorescence assay has been used to estimate the quantity of Maillard products in aqueous seed extracts. We tested whether an accumulation of fluorescent compounds correlates with the loss of seed viability during ageing. Fluorescence of extracts from lettuce (Lactuca sativa) embryonic axes increased after controlled deterioration, but was not correlated with ageing period. Fluorescence of extracts from whole broccoli (Brassica oleracea var. italica) seeds was either unchanged or declined during controlled deterioration. Extracts from naturally aged whole seeds of carrot (Daucus carota), tomato (Lycopersicon esculentum), and cauliflower (B. oleracea var. botrytis) had higher fluorescence than controls, but there was no consistent increase in fluorescence in proportion to the loss of viability. Extracts of naturally aged onion (Allium cepa) seeds exhibited less fluorescence than extracts from seeds with higher viability. We conclude that the fluorescence assay does not have general utility as an index of seed deterioration.