Immunological toolbox available for in situ exploration of pectic homogalacturonan and its modifying enzymes in fruits and vegetables and their derived food products

Abstract

Abstract Pectin and its modifications during growth, ripening, processing and storage play a crucial role in determining the textural properties of fruits and vegetables and their derived food products. Insight into the (enzyme-catalysed) modifications of homogalacturonan, the major structural domain of this polysaccharide which strongly influences the pectin structure–function properties, can be obtained by in situ research tools. Such in situ knowledge is of common interest to both plant and food scientists and requires a good view on available in situ probes and their possible applications, both in a plant physiological and a food-related context. Therefore, the aim of this review is to briefly discuss the available probes towards pectic homogalacturonan and its modifying enzymes and to overview the obtained results using pectin probes, pectin methylesterase probes and pectin methylesterase inhibitor probes in both domains. The presented overview of the available data on in situ research of pectic homogalacturonan and its modifying enzymes emphasises the possibilities of more integrated approaches. Industrial relevance Pectin is a highly important component of plant-based food products. This polysaccharide, naturally present in plant cell walls, is prone to modifications imposed by enzyme activity and/or processing conditions. As the properties of pectin influence product quality attributes such as texture, this macromolecule has been widely investigated in the processing of plant-based foods. An emerging technology for the in situ investigation of food components is using immunological probes. Within this context, the available immunological toolbox for pectic homogalacturonan and its modifying enzymes is summarised in this review article.