Use of High‐pressure Processing for Oyster Shucking and Shelf‐life Extension

Abstract

Whole Pacific oysters (Crassostrea gigas) were processed using high-pressure processing (HPP) treatment from 207 to 310 MPa at 0, 1, and 2 min and stored at Ͻ Ͻ Ͻ Ͻ Ͻ 4 Њ Њ Њ Њ ЊC and evaluated over 27 d. The pH of HPP samples decreased slightly from 6.3 to 5.8 during storage while the control (hand-shucked oysters) dropped to pH 4.1. Moisture content of the controls decreased slightly while HPP samples increased slightly. Pressure treatment did not significantly inhibit lipase activity during the shelf-life study. HPP reduced initial microbial load by 2 to 3 logs and counts remained at a reduced level through the storage study. Descriptive evaluation showed that HPP-treated oysters received higher quality scores than controls during the storage trial.

Randomized, Double-Blinded Clinical Trial for Human Norovirus Inactivation in Oysters by High Hydrostatic Pressure Processing

“…Although the shellfish industry uses HPP at pressures of approximately 300 MPa to facilitate oyster shucking, extend shelf life, and reduce total bacterial counts, including those of Vibrio spp. (19), it is not clear whether the higher pressures required, as suggested by our data, to reduce HuNoV contamination in shellfish will be viable for current commercial units. In addition to evaluation of the upper pressure limits of current commercial units, the consumer acceptability of 600-MPa HPP-treated oysters needs to be investigated.…”

“…In general, HPP has been shown to maintain the appearance, flavor, nutritional quality, and texture of raw shellfish (37,43). HPP also serves a practical application by facilitating the shellfish shucking process by separating the meat from the shell and has been demonstrated to extend refrigerated shelf life (14,19,43). HPP has also been identified recently as a potential means for inactivating parasitic and viral pathogens such as Cryptosporidium parvum oocysts (12), hepatitis A virus, and HuNoV surrogates within raw shellfish (9,22,25,54).…”

High Pressure Processing for Foods Preserving

“…Some authors showed that the pressure resistance of microbial organisms is maximal at temperature [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] o C and decreases significantly at higher or lower temperature (10,11,12).…”

“…hydrostatic pressure treatment is also effective in inactivating other hazardous microorganisms such as E. coli, Salmonella, and Vibrio, as well as many yeasts, molds, and bacteria responsible for food spoilage. the microbiological shelf-life and food quality can be substantially extended by the use of hPP (23,24).…”

High-Pressure Inactivation of Hepatitis A Virus within Oysters

“…HHP is utilized commercially on the United States gulf and western coasts (Gold Seal Oysters Inc., Homa, La., and Nisbet Oyster Inc., Bay Center, Wash.) at pressures of up to 275 megapascals (MPa), principally because it can facilitate the oyster-shucking process and extend the shelf-life of raw oysters due to the reduction of spoilage bacteria (24). Organoleptic evaluations have shown that HHP-treated oysters are acceptable to consumers at treatment pressures as high as 400 MPa or approximately 60,000 lb/in 2 (30).…”