Optimization of oil-in-water emulsion capacity and stability of octenyl succinic anhydride-modified porang glucomannan (Amorphophallus muelleri Blume).

Surfactants are used to reduce surface and interfacial tension to form emulsions. Polysaccharides such as Porang Glucomannan (PG) with high viscosity can be used as surfactants. This research aimed to optimize the concentration of sodium carbonate (Na2CO3) and octenyl succinic anhydride (OSA) in modifying PG using a microwave. The optimization process is carried out using response surface methodology (RSM) with a two-factor central composite design (CCD), namely concentration of Na2CO3 (0.17-5.834%) and OSA (2.17-7.83%). The result showed that the concentration of Na2CO3 and OSA strongly influences emulsion capacity and stability. The optimum conditions that resulted in the highest emulsion capacity and stability were obtained at concentrations of Na2CO3 and OSA which were 2.25% and 6.19%, respectively. Degree of Substitution (DS), FTIR analysis, contact angle, and increased viscosity confirmed that OSA substitution occurred in PG. The characteristics of OSA-modified porang glucomannan (PGOS) such as: emulsion capacity and stability, Degree of Substitution (DS), contact angle, and viscosity increased to 34.6% and 32.5%, 1.02%, 92o, 5720 cP, respectively. FT-IR analysis confirmed the presence of OSA substitution at 1734 cm-1. PGOS can be used as a surfactant or gelator in oleogel production.

Bioaccessibility and antioxidant activity of ß-carotene loaded nanostructured lipid carrier (NLC) from binary mixtures of palm stearin and palm olein.

ß-carotene (ßC) is an essential nutrient for health. It is a potent antioxidant, anti-cancer, and anti-inflammatory substance. However, ßC has high hydrophobicity property, indicating a low absorption level in the digestive tract. The bioavailability of ßC is reasonably low. Lipid-based delivery systems such as nanostructured lipid carriers (NLC) potentially can help to overcome this problem. This research evaluated the bioaccessibility of the nanostructured mixture of palm stearin (PS) and palm olein (PO) and the antioxidant activity of ßC in the structure. ß-carotene bioaccessibility was studied by measuring the micellization during in vitro digestion. Antioxidants activity was measured by 2.2'-azino-bis (3-ethylbenzothiazoline- 6-sulphonic acid) (ABTS) and 2, 2 - diphenyl -1- picrylhydrazyl (DPPH) reduction methods. In vitro gastrointestinal digestion model indicated that nanostructured lipid carrier enhanced bioaccessibility and antioxidants activity of ßC. This suggests that the formulated NLC system can be used effectively to deliver lipophilic bioactive such as ßC in beverage products.

Determination of singlet oxygen quenching rate and mechanism of γ-oryzanol.

Photooxidation is one of the causes of quality deterioration in food. An antioxidant or singlet oxygen quencher is urgently needed to prevent photooxidation. γ-Oryzanol was recognized as a naturally present antioxidant in rice bran products. This research aimed to calculate the singlet oxygen quenching rate and its mechanism of γ-oryzanol to evaluate the potency of γ-oryzanol as singlet oxygen quencher. A series of linoleic acid (50 and 100 mM) or γ-oryzanol (0.7 and 1.5 mM) were prepared separately in ethanol: chloroform (96:4, v/v) containing 25 ppm of erythrosine. High-Performance Liquid Chromatography quantified the degradation of γ-oryzanol. Meanwhile, Gas Chromatography determined the changes in linoleic acid content during photooxidation. The singlet oxygen quenching rate was calculated by steady-state. The singlet oxygen quenching rate of γ-oryzanol was 3.04 × 106/M/s by physical and chemical quenching mechanism. Photooxidation caused the declined of γ-oryzanol by 0.1421 mM/h. Based on singlet oxygen quenching rate calculation, it suggests that γ-oryzanol can perform as a singlet oxygen quencher with slightly dominated by physical quenching mechanism (52.28%). The rest it performed via a chemical quenching mechanism.

Indonesian wild honey authenticity analysis using attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy combined with multivariate statistical techniques.

Wild honeys in Indonesia are still widely believed to be good for health with high economic value. This honey is naturally produced by Apisdorsata bee. In this study, authentication analysis by classification and discrimination of attenuated total reflectance-fourier infrared spectroscopy (ATR-FTIR) spectra was conducted on several wild honeys from various places in Indonesia (n = 186) which then compared to adulterated honey contained commercial sugars of aren (Arenga pinnata), coconut, and cane sugar at 10-50% concentration (n = 57). Combination of spectra measurement at 4,000-650 cm-1 with Chemometric technique by several multivariate analyses resulted in visualization of honey grouping, classification, and regression model that differentiate these honeys, both partial and overall. Principle component analysis multivariate analysis was able to visualize the differentiation of adulterated honey from the authentic ones. Discriminant analysis, a supervised classification technique, was used to differentiate the fake from the authentic honey among those from various origins at wave number range of 4000-800 cm-1 with performance index of 91,8, 90.32-100% sensitivity, and 95. 70-100% specificity. Partial least-squares analysis was used to build a model provided quantitative results of commercial sugars content in honey allegedly added during adulteration. Authentic honeys had commercial sugars content less than 10% with R2 of aren, coconut, and cane sugar of 0.9995, 0.9980 and 0.9998, respectively, with their predictive R2 values of 0.9977, 0.9983 and 0.9946, respectively.

Stabilization of Black Rice (Oryza Sativa, L. Indica) Anthocyanins Using Plant Extracts for Copigmentation and Maltodextrin for Encapsulation.

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.

Immunomodulatory activity of Bengkoang (Pachyrhizus erosus) fiber extract in vitro and in vivo.

Bengkoang (Pachyrhizus erosus (L.) Urban) is one of the most popular edible root vegetables in Indonesia. Bengkoang contains fairly large amounts of carbohydrates and crude fiber. The purpose of this research is to evaluate the immunomodulatory effect of the bengkoang fiber extract (BFE) in vitro and in vivo. BFE was prepared by heating the powder of bengkoang fiber suspended in distilled water at 121 °C for 20 min. BFE facilitated IgM production by the human hybridoma cell line HB4C5 cells. In addition, production of IgM, IgG, and IgA by mouse primary splenocytes was facilitated by BFE in a dose-dependent manner. BFE also significantly facilitated production of both interleukin-5 and interleukin-10 by splenocytes. Immunoglobulin production by lymphocytes from the spleen, Peyer's patch, and mesenteric lymph node were significantly activated by oral administration of BFE to mice for 14 days. The serum immunoglobulin levels of IgG, IgM, and IgA were also significantly enhanced. Furthermore, cytokine production by lymphocytes from the spleen, Peyer's patch, and mesenteric lymph node were also facilitated by oral administration of BFE. These results suggest that BFE has positive effects on the immune system in vitro and in vivo.

Evaluation of immunostimulatory effect of the arrowroot (Maranta arundinacea. L) in vitro and in vivo.

Arrowroot (Maranta arundinacea. L) is an underutilized local crop potentially to be developed as carbohydrate source and functional food in Indonesia. The objectives of this research are to evaluate the immunostimulatory effects of arrowroot extracts in vitro by using animal cell culture techniques, and in vivo by using BALB/c mice. The arrowroot tuber extracts were prepared by heat-treatment at 121 °C for 20 min in distilled water. The IgM production stimulatory activity of arrowroot tuber extracts against human hybridoma HB4C5 cells and mouse splenocytes was assessed. The result indicated that the arrowroot tuber extract stimulated IgM production by HB4C5 cells and immunoglobulin (IgG, IgA and IgM) production by splenocytes in vitro. In addition, the arrowroot tuber extracts strongly enhanced interferon γ production by splenocytes. In vivo study indicated that the diet containing arrowroot extracts increased the serum IgG, IgA and IgM levels in mice. These results revealed that the arrowroot tuber extracts have immunostimulatory effects in vivo as well as in vitro.