Steam, dielectric heating and copper sulfate treatment of inshell pecans
Mandar Patel, Juan L. Silva,Patti C. Coggins and Frank B. Matta
Thesis, Master of Science (Food Science), Mississippi State University. 82 pages. 2008.
2008
บทคัดย่อ
Water and a copper sulfate (CSL) solution at 27, 57 and 88°C; steam pasteurization and dielectric heating were analyzed on their effect in reducing microbial load (APC) and Salmonella Typhimurium on inshell pecans (Carya illinoinensis ). The CSL solution (more effective than water alone) reduced APC by 1.5 (300 s), 2 (60 s) and 4.0 (60 s) log CFU/g at 27, 57 and 88°C, respectively; and Salmonella by 3.0 log at 27°C in 60 s. Steam reduced APC by 3.7 log in 180 s and Salmonella by 4.0 log CFU/g in 30 s. Dielectric treatment reduced APC by 3.0 log and Salmonella by 4.5 log CFU/g in 60 s. Most treatments had no effect on the pecan shell or the nut quality, except for dielectric heating, which gave a slight "roasted" or "burnt" flavor to the nuts. This study showed that a proper antimicrobial-hot water treatment, steam or dielectric heating will be effective in "pasteurizing" pecans, resulting in a safe and wholesome product.