Sensory and Nutritive Qualities of Food Quality and Stability of Precut Mangos and Carambolas Subjected to High-Pressure Processing B.B. BOYNTON, C.A. SIMS, S. SARGENT, M.O. BALABAN, AND M.R. MARSHALL ABSTRACT: Mangos were sliced, vacuum-sealed, and processed at 300 MPa or 600 MPa for 1 min. Fresh mango flavor declined and off-flavor increased during storage at 3 °C, but color, texture, and other sensory attributes changed very little. After 9 wk, the microbial levels in the control were 2 and 3 log CFU/mL greater than the 300 and 600 MPa treatments, respectively. Pressure treatments also slightly reduced fresh mango flavor and increased off- flavor and sweetness. Carambolas were sliced, vacuum-sealed, and processed at 600 MPa for 2, 4, or 6 min; at 800 MPa for 1, 3, or 5 min; or not treated. Samples were stored at 3 °C for 2 and 4 wk and color was evaluated after air exposure. All the 800 MPa treatments reduced browning compared to the control, but the 600 MPa was less effective. Keywords: mango, carambola, precut, high-pressure Introduction M ANGO (MANGIFERA INDICA L.) IS ONE OF THE MOST POPU- lar and widespread tropical fruits in the world, and has increased in worldwide production by nearly 50% between the years of 1971 and 1993 (FAO of the United Nations 1971- 1993. Mangos are of tropical origin and are sensitive to chill- ing injury and shortened shelf life if stored below 10 °C. Most mangos are consumed fresh, but some nonfibrous pulpy mango varieties are used for processing. Both ripe and un- ripe mangos are processed into a variety of products, and are also frozen in a sucrose syrup or as a puree, and are popular in beverages (Morton 1987; Nanjundaswamy 1997). Carambolas are very desirable for their star-shaped slices, crispness, and unique flavor, and the demand for carambola has increased in recent years. Until the mid 1970s, produc- tion and use of carambolas were very limited, but a steady increase in production occurred in the 1980s. By 1990, Flori- da had about 192 hectares of carambola orchards, which produced an estimated 1.6 million kg of packed carambola with a market value of $1.5 million (Weller 1995). Very little carambola is processed; most is consumed fresh, sliced and served in salads, as a garnish on avocado or seafood, or cooked with seafood. Green carambolas are cooked and eat- en as a vegetable, made into a jelly or jam, or pickled. In many countries, the fruit are candied with sugar, honey, or syrup (Morton 1987). The acceptability of the juice and the juice mixed with other tropical fruit juices has also been evaluated by Matthews (1989). The demand for fresh-cut fruits and vegetables has been increasing greatly in the U.S. for the past 10 y. In 1996, con- sumers spent $70 billion on fresh produce with farms taking in $26 billion (U.S. Dept. of Commerce 1998). Fresh-cut sales in the United States in 1994 were $5.8 billion and are expect- ed to increase to $19 billion by 1999 (Hodge 1995). Mangos have high potential for fresh-cut fruit due to the inconve- nience in preparing them for consumption and the high sus- ceptibility to spoilage and chilling injury. Carambola’s poten- tial as fresh-cut is also large since a very popular use of carambola is in fruit salads where freshness and size unifor- mity are important. However, a major problem with cut car- ambola is browning. Polyphenol oxidase (PPO) activity and the phenolic concentration both affect the browning suscep- tibility of carambola (Weller and others 1997). An attempt to reduce browning in sliced carambolas by blanching and chemical treatments was evaluated by Weller (1995). Slices were dipped into a 1% ascorbic acid and 2% cit- ric acid solution, 0.176% 4-hexylresorcinol, 2.5% ethanol so- lution, or water (control) for 5 min. Some fruit were also blanched for 30, 60, 90, or 120 s in steam. The most effective treatment in color retention upon opening the package was the combination of ascorbic plus citric acid solution. Mat- thews and Myers (1995) evaluated the effects of erythorbic/ citric acid, calcium/EDTA, and citric/ascorbic acid blends on vacuum-sealed carambola during refrigerated storage. Ex- cellent yellow color of all carambola slices was maintained with the erythorbic/citric acid and calcium/EDTA. In a study by Weller and others (1997), the susceptibility to browning was compared between carambolas that were sliced and then stored to carambolas that were stored whole and then sliced. Slices that were vacuum-sealed and stored at 4.4 °C for 2 wk browned when exposed to air, but carambolas that were stored whole for 6 wk browned very little when sliced. The increase in browning of the sliced carambola was thought to be from an increase in PPO or due to a decrease in ascorbic acid levels. High-pressure processing is an alternative to heat and/or chemicals and may have potential as a food processing method. The exploration of high-pressure processing on fruits, especially tropical and/or cut fruits, has not received much attention. There are some commercial applications of high-pressure, such as fruit juices, rice cakes, and raw squid in Japan, fruit juices in France, and guacamole in the U.S. (Smelt 1999). Takahashi and others (1993) found that S. cerevisiae and A. niger in satsuma mandarin juice were reduced to below de- tection limits at 300 MPa for 5 min, and M. luteus, C. albi- cans and P. citrinum were reduced to below detection limits at 400 MPa. R. subtilis was unaffected even at 600 MPa and