The aim of the study was to evaluate the effect of heating on the chemical compositions and antifungal properties of nutmeg's oleoresin. Nutmeg's oleoresin was obtained by two steps, distillation followed by maceration. The nutmeg's oleoresin was heated at 100 o C, 120 o C and 180 o C. The chemical compositions were determined by GC-MS, and the antifungal properties by giant colony method. The result of the study showed that yield was 13.6%±0.2% and 24 components were identified. The nutmeg's oleoresin at 100ºC, 120ºC and 180 ºC identified 25, 21 and 20 components. Indeed, heating treatment on nutmeg's oleoresin did not decrease the antifungal properties.

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Black rice (Oryza sativa L. indica) is one of the cereal commodities considered to be a source of anthocyanin. One of the obstacles of using anthocyanins as natural food colorants is their low stability. The objective of this study was to determine the effect of natural plants extracts on anthocyanin copigmentation and to study the stability of the encapsulated copigmented anthocyanin during storage under different temperatures and light exposure. Dried bilimbi leaves (BL) and sow thistle leaves (STL) were extracted using ethanol to obtain the crude flavonoid extract that was subsequently purified using solid phase extraction. Both crude (CBL, CSTL) and purified (PBL, PSTL) extract were used as copigment agents with the molar ratio of 1:0.1 to 1:10 at pH 1 and pH 3. The copigmentation effect was evaluated by measuring the wavelength and absorbance shifts at wavelengths of 500 to 600 nm. The stability of the dried anthocyanin powder was evaluated under different temperatures and light exposure for up to 4 weeks. Anthocyanin was successfully copigmented with BL and STL extracts showing a wavelength shift and absorbance increase at pH 1 and pH 3. Purification of BL enhanced the hyperchromic effect more than that of the crude form, in contrast to the STL. Meanwhile, the retention of absorbance (%) for encapsulated copigmented anthocyanin samples was within 74% to 83% at the end of the storage period. Practical Application Natural food pigment such as anthocyanin obtained from plant extract usually shows very limited stability under various processing conditions. This study shows that color stability of anthocyanin extracted from black rice can be improved by copigmentation with flavonoids extracted from particular plants. Encapsulation of the copigmented anthocyanin could further enhance its color stability. The availability of encapsulated and copigmented anthocyanins with improved color stability is expected to provide more alternatives for especially the beverage industry to choose suitable natural colorant for their products.

The effect of porang (Amorphophallus oncophyllus) glucomannan concentration on the properties of glucomannan-chitosan hydrogel was investigated for Lactobacillus acidophilus FNCC 0051 encapsulation. The spherical shape with a continuous surface of the particle was self-assembly formed. The increase of glucomannan concentration from 0.3 to 0.9 % smoothly increased their small particle size from 1.08 ± 0.02 µm to 2.12 ± 0.00 µm and no significant change on the positive zeta potential values. The polydispersity indexes with the value between 0.4 to 0.5 were categorized as uniform particles. However, these values were higher compared to other studies which used konjac glucomannan-chitosan as the hydrogel materials. The encapsulation study with Lactobacillus acidophilus FNCC 0051 showed that the highest value was achieved when the same ratio of glucomannan and chitosan was applied (0.5 %). The viability study proved the perfect protection of hydrogel during 56 days of cold storage and pasteurization treatment with the cell viabilities of 100 % and 58.13 ± 18.5 %, respectively. HIGHLIGHTS Glucomannan concentration influenced particle size and encapsulation efficiency of hydrogel Hydrogel was potential as acidophilus carrier in the gut due to its pH sensitivity Hydrogel had continuous surface to provide a stronger physical barrier for the acidophilus against harsh environment Hydrogel proved well protection of acidophilus during pasteurization and cold storage GRAPHICAL ABSTRACT