DETERMINING TECHNOLOGICAL PARAMETERS OF THE PROCESSING OF GREEN PEPPER PRODUCTS

Abstract

Peppercorn (Piper nigrum L.) is widely grown in Vietnam, including in Quang Tri province and is used as a food spice. Green peppercorn contains many chemical components, especially oils and alkaloids. Green pepper is harvested while still green, with only 5 - 10% of the fruits in a cluster having ripened. The endocarp has not yet hardening and the seed is still soft. The whole cluster is harvested while still green on the plant, then dried, packaged and preserved. The aim of this research is to determine the technological parameters for drying green peppercorn of Quang Tri province using freeze-drying combined with infrared radiation. The cold drying method combined with infrared radiation is a method of drying materials under low temperature conditions combined with infrared lamps to dry the materials. This technology has many advantages, including reduced drying time, uniform temperature distribution, flexibility in heating by zone, simple and compact equipment and especially energy saving, allowing drying at low temperatures to minimize product quality degradation due to heat. The results show that 2000 g of green peppercorn soaked in a solution of 3000 ml filtered water, 7.5 g citric acid and 2 g salt, the drying temperature is 40°C, the thickness of the green peppercorns layer on the drying tray is 11 mm (equivalent to two layers of pepper) and the wind speed is 1.5 m/s. The drying time per batch of green peppercorn is more than 37 hours 15 minutes, the distance between the infrared bulbs is 10 cm and the final product moisture content reaches 7 - 8%. The product has an essential oil content of 2.15 ± 0.01%, an alkaloid content of 0.065 ± 0.001%, a greenish-yellow color, a natural aroma, a naturally spicy taste and is dry, crispy, and less prone to wrinkling.