California is the world’s largest producer of almonds. With its ideal growing conditions, including a mild climate (hot dry summers and cool rainy winters), rich soil and abundant sunshine, this area produces about 80% of the global almond supply, exporting to nearly 90 countries. Development of proper almond processing technologies could facilitate the growth of California almond industry, provide high-quality and nutritious almonds to consumers.
Main findings:
- Efficient and sustainable drying technology was developed for off-ground harvested almonds based on hot air (HA) heating. The new drying technology significantly improved the drying efficiency and drying throughput, while obtained high quality (no significant cavity, discoloration, concealed damage or deterioration of oil quality).
- A series of sorting methods based on the dimension characteristics and aerodynamic properties of the almonds were developed to separate the freshly harvested almonds at different maturity stage and initial moisture levels. The sorting methods was helpful for improving the moisture uniformity of almonds, and reducing the energy consumption in drying process.
- A new sequential IR and HA roasting approach was developed for almonds, which could significantly reduce the roasting time and operating cost without negatively affecting the texture, flavor and oil quality of roasted almonds.
- Efficient pasteurization method was developed for almond kernels based on IR heating. IR heating of almonds to 100oC with subsequent holding at 90oC for 10 min provided more than 5.5-log reduction of Pediococcus number on the kernels.
Selected Publications:
Venkitasamy, C., C. Zhu, M.T. Brandl, F. J.A. Niederholzer, R. Zhang, T.H. McHugh, and Z. Pan. 2018. Feasibility of using sequential infrared and hot air for almond drying and inactivation of Enterococcus faecium NRRL B-2354. LWT – Food Science and Technology. 95:123-128. https://doi.org/10.1016/j.lwt.2018.04.095.