This study evaluated the effect of two fruit sizes (3.5×2.5×1.0 and 1.2×1.2×0.8 cm 3 ) and processing time (impregnation and relaxation times; both for 10 and 20 min), on some vacuum impregnation parameters of cantaloupe and apple. Fruit size and processing time significantly affected the mass fraction of fruit occupied by impregnation liquid (X value) and the effective porosity (ε e ) of apples more than cantaloupe. High surface area of fruit and long processing times allowed for significant liquid penetration into the fruit. This study has shown that the effectiveness of vacuum impregnation is a surface-controlled phenomenon.

This study evaluated the effect of two fruit sizes (3.5×2.5×1.0 and 1.2×1.2×0.8 cm 3 ) and processing time (impregnation and relaxation times; both for 10 and 20 min), on some vacuum impregnation parameters of cantaloupe and apple. Fruit size and processing time significantly affected the mass fraction of fruit occupied by impregnation liquid (X value) and the effective porosity (ε e ) of apples more than cantaloupe. High surface area of fruit and long processing times allowed for significant liquid penetration into the fruit. This study has shown that the effectiveness of vacuum impregnation is a surface-controlled phenomenon.

The sensory properties and bacterial viability of intermediate-moisture apple and cantaloupe supplemented with Lactobacillus acidophilus and packed in vacuum packaging were monitored during eight weeks of storage at refrigerated and room temperatures. The intermediate-moisture apple and cantaloupe had higher lightness value and better bacterial survival when the fruit samples were stored at refrigerated temperatures. The numbers of total microorganisms and lactic acid bacteria in the fruit samples reduced significantly to below 1.0 log cfu/g after eight weeks of storage at room temperature. On the other hand, refrigerated storage maintained high numbers of lactic acid bacteria-7.94±0.02 and 9.44±0.38 log cfu/g, in the apple and cantaloupe samples, respectively, at the end of the storage period. A sensory panel preferred the intermediate-moisture fruits stored at chilled temperatures compared to room temperatures.

Vacuum impregnation is a non-destructive technology, use to introduce external liquid into the structures of food matrices. The aim of this study was to investigate the effect of vacuum and relaxation times on the qualities of roselle (Hibiscus sabdariffa L.) and butterfly pea (Clitoria Ternatea L.) vacuum impregnated rice. A vacuum pressure of 50 mbar was applied for 10 and 20 min (Vacuum time), following atmospheric pressure restoration for 10 and 20 min (Relaxation time). The result shown that, lightness (L* value) of both herbal plants vacuum impregnated rice reduced with increasing the vacuum and relaxation times. Whereas, the values of water loss, mass fraction of fruit occupied by impregnation liquid (X), sample volume deformation () and effective porosity ( e ) were increased as increasing the vacuum and relaxation times. In addition, the impregnated rice treated with 20 min vacuum time and 20 min relaxation time significantly highest antioxidant properties including, total phenolic compounds, total flavonoids, total anthocyanins, DPPH-radical scavenging activity and ferric reducing antioxidant power (FRAP value). The roselle vacuum impregnated rice showed significant higher total flavonoids (483.79 mg Catechin equivalent/100g) and FRAP value (55.64 Trolox equivalent/100g) than butterfly pea vacuum impregnated sample (155.09 mg Catechin equivalent/100g and 25.41 Trolox equivalent equivalent/100g, respectively). This study indicated that the longer vacuum and relaxation times were useful for enriching the herbal plant extracts in rice.