STARCH DAMAGE .1. CHARACTERIZATION OF GRANULE DAMAGE IN BALL-MILLED POTATO STARCH STUDY BY SEM

Scanning electron microscopy (SEM) has been used to classify and quant ify the types of damage evident in a population potato starch granules following ball milling. Whilst the majority of granules remained unda maged, a significant (p < 0.01) increase in the number of granules wit h localized damage was observed (1.6% to 15.1%). A variety fo types of localised damage were discernable, ranging from areas where small amo unts of granule surface material had been removed, to large areas poss essing coarse surfaces caused by extensive removal of material. The ge neration of this latter category termed 'rough faces', was the most si gnificant and predominant change following ball milling (p < 0.05). Ba ll-milling was therefore attributed to the penetration of an outer gra nule layer, via the removal of surface material at existing points of weakness. This produced rough, disrupted areas of the granule surface, which are more likely to be susceptible to hydration and enzyme attac k.