RADIO-FREQUENCY TECHNOLOGY FOR FRESH STUFFED PASTA PASTEURIZATION/PRE-DRYING PROCESS: PRELIMINARY RESULTS

Radio frequency (RF) applications to food process are well known due to the possibility of quickly and uniformly heating food matrix (Orsat and Vi- jaya Raghavan, 2005; Guo et al., 2006). Fresh stuffed pasta conventional production technology consists of a first steam pasteurization for a period varying from 2 to 10 min depending on pasta size and weight, initial microbial density and wet steam or superheated steam, followed by a drying phase with forced hot air at a tempera- ture not exceeding 65°-70°C to increase pasta consistency and stabilize the shape. Fresh semolina pasta RF pasteurization/pre-dry- ing process is already used by some companies to obtain: a reduction of microbiological param- eters, reduced time pasteurization, a better cook- ing bheavior, keeping a great intensity taste and aroma typical of fresh semolina pasta. Fresh stuffed pasta production has several healthy and technology problems with respect to fresh semolina pasta, thus RF pasteurization/ pre-drying process requires a proper implementa- tion and evaluation of effects on different types of products. In this study we have examined three different types of fresh stuffed pasta, cappelletti stuffed with ham, fagottini stuffed with cheese, and tortellini stuffed with meat. Three different RF treatments were carried out: 3 kV were applied to fresh pasta stuffed with ham and meat and 2 kV to fresh pasta stuffed with ricotta cheese for a to- tal time of 10 and 8 min, respectively. RF plant consists of a single steel tunnel, in which electrodes are placed and kept at 27.12 MHz, where simultaneously pre-drying and pasteuriza- tion of fresh pasta occur (STC, Science Technol- ogy & Consulting). Microbiological analysis of different fresh stuffed pasta samples, pre- and post-pasteurization were made by the Tempo System (bioMérieux, France). Preliminary results in different types of fresh stuffed pasta show that RF pasteurization/pre- drying process causes reduction of some micro- biological parameters