How does HPP affect the microbial load of food products?

High Pressure Processing (HPP) is a food preservation technique that involves subjecting food products to high levels of hydrostatic pressure. This process significantly impacts the microbial load in food by inactivating a wide range of microorganisms, including bacteria, yeasts, and molds, without the need for high temperatures that can alter the food's taste and nutritional quality.

The effectiveness of HPP in reducing microbial load is attributed to its ability to disrupt cellular structures and interfere with biological functions of the microbes. The pressure applied can cause physical changes, such as breaking down cell walls, leading to cell lysis, which ultimately results in the inactivation or death of the microorganisms present in the food. This reduction in microbial load enhances the food's safety, extending its shelf life while maintaining its freshness and nutritional benefits.

HPP has been shown to be effective against both spoilage organisms and pathogens, making it a valuable technique in food processing aimed at improving food safety and quality. Consequently, the primary effect of HPP on microbial load is a reduction, making it the correct answer to the question.