| Popis: |
The objective of this research was to investigate how the texture of pears (Pyrus communis L) is affected during heat treatment. The following parameters were varied: temperature t = 70÷100 °C and time, τ = 5÷20 minutes. During heat treatment pears were immersed in a sugar syrup (two variants of sucrose source were used – granulated sugar and brown sugar). Were analyzed several physico-mechanical properties (moisture, fruit dimensions, aspect ratio, geometric mean diameter, sphericity, surface area, fruit mass, fruit volume, fruit density, bulk density, density ratio, porosity). The structure of heat treated pears was examined by fluorescence and phase contrast combination microscopy and texture was measured with a penetrometer type Fruit Texture Analysis (FTA). The average fruit mass ranged from 115.55 to 136.5 g. The bulk density, porosity and fruit hardness determined as 365.84 - 543.12 kg/m3; 78.81 – 95.28 % and 9.87 - 13.74 N/mm between samples. A better firmness and a higher temperature in the center of the sample were observed for brown sugar syrup treated pears. |
