Effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milk

Abstract

The effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milks was investigated. Hazelnut milk samples were produced from cold pressed hazelnut cake and homogenized up to 150 MPa pressure. Microstructural and rheological properties of products, except temperature sweep, were greatly affected by HPH treatments. Homogenized samples showed significant reduction in particle size, which turned from bimodal and poly-disperse to monodisperse distributions. HPH decreased the consistency of products from 91.82 to 0.51 Pa.s(n) and increased flow behavior index from 0.15 to 0.36. All samples showed higher values G' than G '', which indicates that samples could be classified as soft-gel network, and hazelnut milk samples did not obey the Cox-Merz rule without multiplying angular frequency with shift factor. In conclusion, HPH can be used to reduce the consistency of samples and the friction loss, thus minimizing the amount of energy required to flow during processing and distribution. Industrial relevance. Vegetable based beverages are available at any supermarket as an alternative to dairy products with an increasing consumer acceptance. Between these beverages hazelnut milk samples are the most noteworthy products due to important role in human nutrition and health, and moreover due to well accepted and widely consumed product. Due to its composition, hazelnut milks have very high consistency, and therefore, the energy consumption for processing and handling is too high. In this research, the high pressure homogenization (HPH) technology was successfully proposed to be used for improving microstructural properties, and hence reducing its consistency. The energy consumption during processing and distribution can be minimized by reducing the consistency and friction losses of product.