Application of Nanocellulose Biofilter from Pineapple Peel Waste for Water Microbes Removal.

This research aimed to assess the effectiveness of nanocellulose biofilter (NCB) made from pineapple peel waste to reduce the number of microbes in water. Further processing of cellulose from nata de pina into nano size was proposed, then transformed into a filter membrane. Three types of NCB were developed: bacterial cellulose acetate membrane, bacterial cellulose acetate membrane with TiO2 treatment, and bacterial cellulose acetate membrane with TiO2 and graphite nanoplatelet treatment. These NCBs were used to filter microbes in several water sources in Padang City, West Sumatra Province. The filtering process was carried out using a filter holder where the NCB had been installed. The number of microbes contained in the water, including E. Coli, was determined before and after filtering. As a result, all NCBs reduced the total microbes in water by about 50%. Furthermore, when applied to water pollutant bacteria, E. Coli, all prepared NCBs reduced them by more than 90%. The effectiveness of all NCBs to remove microbes' contamination, especially bacteria, looks very promising with or without TiO2 and graphene reinforcement. Although the efficacy of all NBC for microbial water purification was relatively similar, further experiments to clarify the superior of TiO2 and graphite nanoplatelet on NCB need to be carried out, especially in reducing chemical contamination.

Properties of bacterial cellulose acetate nanocomposite with TiO2 nanoparticle and graphene reinforcement.

Agricultural waste is considered a promising source for bacterial cellulose production. This study aims to observe the influence of TiO2 nanoparticles and graphene on the characteristic of bacterial cellulose acetate-based nanocomposite membranes for bacterial filtration in waters. Bacterial cellulose was produced from the pineapple peel waste using fermentation process. High-pressure homogenization process was applied to reduce bacterial nanocellulose size and esterification process was carried out to produce cellulose acetate. Nanocomposite membranes were synthesized with reinforcement of TiO2 nanoparticles 1 % and graphene nanopowder 1 %. The nanocomposite membrane was characterized using an FTIR, SEM, XRD, BET, tensile testing, and bacterial filtration effectiveness using the plate count method. The results showed that the main cellulose structure was identified at the diffraction angle 22° and the cellulose structure slightly changed at the peak of diffraction angles of 14° and 16°. In addition, the crystallinity of bacterial cellulose increased from 72.5 % to 75.9 %, and the functional group analysis showed that several peak shifts indicated a change in the functional group of membrane. Similarly, the surface morphology of membrane became rougher with the structure of mesoporous membrane. Moreover, adding TiO2 and graphene increases crystallinity and bacterial filtration effectiveness of nanocomposite membrane.

Identification of 9,10-anthraquinone contamination during black and green tea processing in Indonesia.

Black and green tea are popular owing to their unique flavors and health benefits. However, these teas can be contaminated with anthraquinones, which are associated with health risks in humans. Levels of 9,10-anthraquinone were determined at each step of the manufacturing process for green and black tea using gas chromatography-tandem mass spectrometry. For green tea, anthraquinone was present beginning at the withering process and increased in concentration until the first drying step. Additionally, for black tea, the first drying step resulted in a significant increase in anthraquinone content, whereas the concentration decreased during the final drying step. For black tea, anthraquinone was also detected during withering, although the concentration continued to increase throughout the entire procedure, particularly during drying. Therefore, it can be suggested that the presence of anthraquinone in these teas was influenced by the smoke emitted by the wood fires used to drive the processing machinery.

Total Phenolic, Anthocyanin, Catechins, DPPH Radical Scavenging Activity, and Toxicity of Lepisanthes alata (Blume) Leenh.

Anthocyanins and catechin are natural antioxidants presented in many plants. Lepisanthes alata (Blume) Leenh is a plant with fruit that ripens to an intense red. This coloring suggests a high polyphenol content. However, limited information is available regarding the polyphenol or other antioxidant content in this fruit or its suitability as a food additive. The purpose of this research was to determine the total phenolic, total monomeric anthocyanin, catechin, epicatechin and epigallocatechin gallate content, DPPH radical scavenging activity, and toxicity in rind, flesh, seed, and whole fruit of L. alata. This research was conducted using an exploratory method with four analyses; samples from six parts of the plant were analyzed for polyphenols (rind, fruit pulp, seeds, whole fruit, bark, and leaves), four for anthocyanins (rind, fruit pulp, seeds, and whole fruit), and six parts of the plant for DPPH radical scavenging activity in water, methanol, and ethanol (rind, fruit pulp, seeds, whole fruit, bark, and leaves) and toxicity. This plant was found to contain high levels of polyphenol; the lowest level was measured in the flesh (0.64 mg GAE/g of DW) and the highest in the whole fruit (2.87 mg GAE/g of DW). The lowest anthocyanin content is found in the flesh and the highest in the rind with the respective average values of 672.27 mg/100 g FW and 1462.82 mg/100 g FW. Epicatechin is the major catechin in whole fruit and bark of L. alata. L. alata DPPH radical scavenging activity was in the range of 21.23 to 92.5% depending on the solvent, and the highest activity was recorded in bark in ethanol extract. No toxins were found in any part of the plant indicating that an extract from it could be safely used as a natural antioxidant supplement in processed foods to protect against free radicals.

Identification of a freshness marker metabolite in stored soybean sprouts by comprehensive mass-spectrometric analysis of carbonyl compounds.

The objective of this study was to identify metabolites that quantitatively indicate degrees of freshness of soybean sprouts. Self-cultivated soybean sprouts were stored at 5 °C, 10 °C or 20 °C, and respiratory CO2 production rates were monitored using gas chromatography during storage. Carbonyl compounds (CCs) were analyzed comprehensively using mass-spectroscopic metabolomics analyses. CCs were derivatized using dansyl hydrazine (DH) and were then analyzed using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-MS/MS) with multiplexed multiple reaction monitoring (MRM). In the MRM chromatogram, 171 to 358 peaks were observed from stored soybean sprouts. Principle component analysis and discriminant analysis (PCA-DA) selected the CC-DH derivative ion with a m/z 512 at a retention time of 9.34 min as the most significant metabolite. Searching online metabolomics databases and matching fragment patterns of product ion mass spectra of an authentic standard revealed abscisic acid is a freshness marker of soybean sprouts.