Shelf-Life Evaluations of Liquid Foods Treated by Pilot Plant Pulsed Electric Field System

Abstract

There is a pressing need to validate the shelf‐life extension of Pulsed Electric Field (PEF) treated foods. This study was designed to evaluate the shelf‐lives of cranberry juice and chocolate milk as a function of PEF and the interaction of PEF+heat treatments. Cranberry juice was exposed to PEF and PEF+heat (60C), and chocolate milk to PEF+heat (105 and 112C). Microbial analysis and color measurement were performed on untreated and treated cranberry juice and chocolate milk aseptically packaged and stored at 4, 22, and 37 C for 197 and 119 days, respectively. Microbial analysis of cranberry juices demonstrated that the shelf‐life of PEF and PEF+heat treated juices stored at 22 and 37 C increased significantly during 197 days (p<0.05). The shelf‐life of chocolate milk treated by PEF+105C and PEF+112C increased significantly at all storage temperatures (p<0.05). The PEF nor PEF+heat treatments did not result in any significant differences in color retention of either cranberry juice or chocolate milk (p>0.05). This study presented that PEF and PEF+heat treatments were very effective to increase shelf‐lives of cranberry juice and chocolate milk.

Pulsed electric fields inactivation of Lactobacillus plantarum in an orange juice–milk based beverage: Effect of process parameters

“…Studies on the possibility of applying PEF in fruit juices have proliferated in recent years, concentrating mainly on apple and orange juice and other substrates of a different nature such as soymilk , apple cider (Evrendilek et al, 2000), chocolate milk (Evrendilek, Dantzer, Streaker, Ratanatriwong, & Zhang, 2001), mixed juices (Rodrigo, Martínez, Harte, Barbosa-Cánovas, & Rodrigo, 2001;Rodrigo, Barbosa-Cánovas, Martínez, & Rodrigo, 2003), model beer (Ulmer, Heinz, Gänzle, Knorr, & Vogel, 2002), horchata (Spanish beverage) (Selma, Fernández, Valero, & Salmeró n, 2003) and beer with gas (Evrendilek, Li, Dantzer, & Zhang, 2004). However, there are no studies on the application of PEF in the inactivation of microorganisms in juice-milk mixtures such as the beverage under study.…”

Effects of pulse polarity and pulse delaying time on pulsed electric fields-induced pasteurization of E. coli O157:H7

“…The PEF processing in both bench and pilot plant scale has been successfully applied to various liquid products including apple, orange and cranberry juices, and whole, 2%, skim and chocolate milk (Evrendilek, Streaker, Dantzer, Ratanatriwong, & Zhang, 2001;Evrendilek et al, 2000;Evrendilek, Zhang, & Richter, 1999;Reina, Jin, Zhang, & Yousef, 1998;Qiu, Sharma, Tuhela, Jia, & Zhang, 1998).…”

Pasteurization of milk with pulsed electric fields

“…If shelf-life of products can be extended considerably (even when stable at room temperature), the feasibility of shipping Pasteurization of milk with pulsed electric fields 413 and marketing food products on a wider scale becomes possible, an excellent alternative for food processors and the dairy industry to consider; longer shelflife also could reduce economic losses when there is overproduction. As mentioned earlier in this chapter, some preliminary studies on PEF processing showed that the shelf-life of milk can be extended by reducing the growth rate of certain spoilage microorganisms during storage (Evrendilek et al, 2001). Chocolate milk treated under PEF (35 kV/cm; 1.4 "s pulse width; 45 "s total time) and PEF plus thermal treatment (60ëC) showed important shelf-life extension of samples stored at temperatures of 22ëC and 37ëC.…”

“…Chocolate milk treated under PEF (35 kV/cm; 1.4 "s pulse width; 45 "s total time) and PEF plus thermal treatment (60ëC) showed important shelf-life extension of samples stored at temperatures of 22ëC and 37ëC. When chocolate milk was stored at 4ëC, following PEF or PEF plus heat treatment, no microbial growth was detected after 197 days of storage (Evrendilek et al, 2001). Recent studies have shown that the shelf-life of milk thermally pasteurized previously, followed by PEF treatment, can extend the storage life of milk considerably.…”