S: Sensory & Food Quality Survival Analysis Applied to the Sensory Shelf-Life Dating of High Hydrostatic Pressure Processed Avocado and Mango Pulps D.A. Jacobo-Vel´ azquez, P.A. Ramos-Parra, and C. Hern´ andez-Brenes Abstract: High hydrostatic pressure (HHP) pasteurized and refrigerated avocado and mango pulps contain lower microbial counts and thus are safer and acceptable for human consumption for a longer period of time, when compared to fresh unprocessed pulps. However, during their commercial shelf life, changes in their sensory characteristics take place and eventually produce the rejection of these products by consumers. Therefore, in the present study, the use of sensory evaluation was proposed for the shelf-life determinations of HHP-processed avocado and mango pulps. The study focused on evaluating the feasibility of applying survival analysis methodology to the data generated by consumers in order to determine the sensory shelf lives of both HHP-treated pulps of avocado and mango. Survival analysis proved to be an effective methodology for the estimation of the sensory shelf life of avocado and mango pulps processed with HHP, with potential application for other pressurized products. Keywords: high hydrostatic pressure processing, sensory shelf life, survival analysis Practical Application: At present, HHP processing is one of the most effective alternatives for the commercial nonthermal pasteurization of fresh tropical fruits. HHP processing improves the microbial stability of the fruit pulps significantly; however, the products continue to deteriorate during their refrigerated storage mainly due to the action of residual detrimental enzymes. This article proposes the application of survival analysis methodology for the determination of the sensory shelf life of HHP-treated avocado and mango pulps. Results demonstrated that the procedure appears to be simple and practical for the sensory shelf-life determination of HHP-treated foods when their main mode of failure is not caused by increases in microbiological counts that can affect human health. Introduction High hydrostatic pressure (HHP) processing is an effective non- thermal technology for the pasteurization and shelf-life enhance- ment of tropical fruit pulps and other food products. In many cases, properly HHP-pasteurized fruit pulps are microbiologically stable during storage. However, the quality of these products is affected by the residual activity of enzymes that are not com- pletely inactivated by the commercial HHP treatments. Therefore, low- and high-acid fruit pulps processed by HHP are commonly stored under refrigeration to reduce quality losses. Avocado and mango pulps processed by HHP are products commercially avail- able, and have been reported to be stable to the action of spoilage microorganisms during refrigerated storage (L ´ opez-Malo and oth- ers 1998; Guerrero-Beltr´ an and others 2006; Ramos-Parra 2006; MS 20090893 Submitted 9/10/2009, Accepted 3/24/2010. Authors Jacobo- Vel´ azquez, Ramos-Parra, and Hern´ andez-Brenes are with Dept. of Biotechnology and Food Engineering, School of Biotechnology and Health, Tecnol´ ogico de Monterrey- Campus Monterrey, E. Garza Sada 2501 Sur, C.P. 64849, Monterrey, N.L., M´ exico. Author Jacobo-Vel´ azquez is also with Dept. of Horticultural Sciences, Texas A&M Univ., HFSB Building, Room 202, MS 2133, College Station, TX 77843- 2133, U.S.A. Direct inquiries to author Hern´ andez-Brenes (E-mail: chbrenes@ itesm.mx). Jacobo-Vel´ azquez and Hern´ andez-Brenes 2009). Although these products are safe for human consumption for long-storage peri- ods, consumers reject them after a certain period of time due to physicochemical and sensory changes. Previous shelf-life estimation reports for HHP-treated products generally base their determinations on physicochemical measure- ments, which can result in the overestimation of the shelf life of these products. However, when food products have enhanced microbiological stability, their shelf life is limited by changes in their sensory properties (Hough and others 2003). Commercial HHP-treated foods generally contain low levels of microorgan- isms and their acceptability is mainly affected by storage-related sensory changes, therefore, survival analysis methodology is be- ing proposed herein as a suitable option to determine their shelf life. Survival analysis is a statistical data analysis procedure widely used in clinical, biological, and epidemiological studies, and it has been proposed as a potential tool to estimate the sensory shelf life of microbiologically stable food products. The key concept of this shelf-life determination methodology is to focus on the risk of rejection by consumers rather than on product deteriora- tion (Hough and others 2003; G´ ambaro and others 2004a, 2004b, 2006; Salvador and others 2006). The objective of this study was to determine the sensory shelf life of HHP-treated avocado and mango pulps. To the best of our knowledge, there are no previous reports focused on the C  2010 Institute of Food Technologists R  S286 Journal of Food Science  Vol. 75, Nr. 6, 2010 doi: 10.1111/j.1750-3841.2010.01656.x Further reproduction without permission is prohibited