Solid Acid Hydrolysis for Isolation of Cellulose Nanocrystals and Chitin Nanocrystals – A mini review

Cellulose and chitin are two of the most abundant biopolymer on earth, have been attracted a lot of interest from many researchers, especially related to their nanoparticles form. Recently the method to extract them into nanoscale materials mostly by mineral or liquid acid hydrolysis, such as sulfuric and hydrochloric acid. Despite their high yield production, many disadvantages are produced by their use as a hydrolysis catalyst, such as low thermal stability and are difficult to be functionalized due to the presence of sulfate groups, tendency to be aggregated due to the bare surface charge density, the potential excessive degradation of cellulose; and large amounts of effluent will be produced due to the neutralization stage and corrosion hazards to the equipment and environment. To overcome the drawback of those acids, solid acid can be used to produce cellulose (CNC) and chitin nanocrystals (ChNC). Their ability to recrystallize and recycle makes them more environmentally friendly, furthermore, most of the acid can do esterification on the surface of cellulose and chitin. The purpose of this paper is to provide a critical review of recent progress related to solid acid hydrolysis since they have interesting characterization even some of their attribute is better than the conventional method.

Characteristics and Chemical Compounds Liquid Smoke of Mangrove Stem Bark Waste from Charcoal Industry

In Batu Ampar, the charcoal industry, West Kalimantan, used Rhizophora sp. mangrove to produce liquid acid with mangrove stem bark waste as a side product. Pyrolysis of liquid smoke of mangrove stem bark waste at a temperature of 4000C for 6 hours resulted in a yield of 33.97% with pH, specific gravity, and color were 2.8, 1.004, and brown, respectively. Analysis of GC-MS showed that liquid smoke without distillation has 16 chemical compounds where the main components were acetone (12.32%), acetic acid (11.62%), 2-furancarboxaldehyde (26.72%), 5-methyl furfural (13.87%) and phenol, 2-methoxy (13.31%). Furthermore, this liquid smoke is distilled at 1000C to produces residual liquid smoke and distillate liquid smoke. The residual liquid smoke resulted in a yield of 95.8% with characteristics of pH, specific gravity, and color were the lowest 2.73, 1.004, and dark brown, respectively. The liquid smoke residue contained 12 chemical compounds where the main components were butanal, 3-hydroxy- (17.46%), acetone (17.15%), acetic acid (32.27 %), and 2-furancarboxaldehyde (13.28%). Distillate liquid smoke resulted in a yield of 4.2% with pH, specific gravity, and color characteristics, which were 2.8, 1.001, and yellow, respectively. This liquid smoke contained nine chemical compounds, with the main components were ethyl ester (26.69%) and ethylene glycol (64.70%). Based on the GC-MS data, the liquid smoke from mangrove leather waste did not contain poly-aromatic hydrocarbon (PAH) or benzopyrene compounds.

Effect of the composition of flour nutrient substrates on the activity of microorganisms from the bacterial concentrates

The need to develop the technology of liquid acid-forming ferments using bacterial concentrates for the production of national types of bread in discrete mode was shown. The choice of bacterial concentrates was based on the optimal pH (4.5 – 5.5) and temperature (30ºC – 40ºC) of flour nutrient substrates, which are necessary to ensure the directed cultivation of microorganisms in the technology of liquid acid-forming ferments. The choice of bacterial concentrates was based on the maximum acidity that microorganisms could provide after two days of cultivation and which should be in the range of 100 to 180 degrees of Turner. The use of Belarusian bacterial concentrates on the basis of the comparative characteristics was proposed. Flour nutrient substrates for the cultivation of microorganisms from bacterial substrates have been proposed. They contained traditional components (rye flour, rye malt) and components for stimulation of activity of microorganisms from bacterial concentrates (dairy whey in liquid form, Echinaceae purpurea herba). The choice of the ratio between the components was based on the peculiarities of the technology of production of national types of bread and the possibility of providing microorganisms from bacterial concentrates with the necessary nutrients. Microorganisms of bacterial concentrate "IM-pro 1" (a consortium of dried lactic acid bacteriums and bifidobacteriums) using the proposed flour nutrient substrates during cultivation had the best activity for a shorter period of cultivation. This made it possible to propose the use of this bacterial concentrate as a source of microorganisms in liquid acid-forming ferments for national types of bread and to ensure the preparation in one stage.

Energy and Nutrient Concentrations of Water Buffalo Milk and Liquid and Dried Whey: Potential Dietary Supplement to Address Malnutrition in Lao PDR

Objectives In Lao PDR, 33.5% of children <5 years are stunted, 26% are underweight and 8% are severely wasted. Nutritional rehabilitation of malnourished children often requires dietary protein (PRO) and energy supplementation. Water buffalo (WB) native to SE Asia produce milk with more fat and PRO than dairy cow (DC) milk. Although WB milk is not typically consumed in Lao, it is used to make cheese. Whey, a byproduct of cheese production and a source of PRO and energy, is currently discarded in Lao. We analyzed and compared energy and macronutrient concentrations of WB milk and liquid and dried acid whey to DC milk and acid whey data in the 2020 USDA nutrient database to determine potential as a locally-sourced protein supplement. Methods WB milk and whey samples were obtained from the Lao Buffalo Dairy in Lao PDR. Nutrient analysis was performed by Mahidol University, Bangkok, Thailand. Crude PRO and fat concentrations were measured by Kjeldahl and Soxtec™ technology, respectively; and carbohydrate (CHO) and energy concentrations were calculated by weight-difference and standard equations. Results WB milk contained 4.5 ± 0.0 g PRO, 7.6 ± 0.3 g fat, 5.2 ± 0.3 g CHO and 107 ± 3 kcals per 100 g milk. WB liquid acid whey contained 0.8 ± 0.3 g PRO, 0.6 ± 0.2 g fat, 5.4 ± 0.3 g CHO and 29.6 ± 2.1 kcals per 100 g whey. WB dried acid whey contained 9.4 ± 3.3 g PRO, 6.5 ± 1.8 g fat, 70 ± 4.9 g CHO and 376 ±13 kcals per 100 g dried whey. PRO (P < 0.01), fat (P < 0.01) and energy (P < 0.01) concentrations were higher in WB than DC milk. Energy (P < 0.01) and fat (P < 0.01) concentrations were higher in WB than DC liquid acid whey. Energy concentration (P < 0.01) was higher in WB than DC dried acid whey; PRO concentrations were not different (P > 0.14) but met USDA PRO powder criteria of 7 g PRO/100 g dried whey. Conclusions WB milk and liquid and dried acid whey contain sufficient amounts of PRO, fat and energy to develop a locally-sourced nutritional supplement to rehabilitate malnourished children. Funding Sources Funding for this research was supported by the OHSU Foundation, OHSU Graduate Programs in Human Nutrition, Vejdusit Foundation, and Bangkok Dusit Medical Services. WB milk and whey samples were generously donated by the Lao Water Buffalo Dairy in Luang Prabang, Lao PDR.

Effects of Methane Fermentation on Spectral Properties of Fulvic Acid Extracted from Peat through Liquid Acid Precipitation

The effects of acid precipitation with different liquid acids on spectral properties of fulvic acid extracted from peat was studied to select the most appropriate liquid acid for the acid precipitation step of the alkali solution acid precipitation method, and the new process mechanism of peat utilization by coupling methane fermentation and extraction of fulvic acid was analyzed. The alkali solution acid precipitation method was adopted to extract fulvic acid from the methane-fermented group and methane-unfermented group. Different liquid acids were used to conduct acid precipitation during the extraction. And then, the characterizations of fulvic acid samples were conducted through Fourier infrared spectroscopy, UV-Vis spectroscopy, and fluorescence spectroscopy. The yield and content of fulvic acid decreased significantly after methane fermentation. During the methane fermentation process, some fulvic acid was consumed and utilized by microorganisms to promote the methane fermentation process, resulting both in the decrease of methyl, hydroxyl, and ether bonds and in the increase of methylene, carbonyl, conjugated double bond, benzene rings, and other groups. The E4/E6 ratio shows that the E4/E6 ratio of fulvic acid was decreased after methane fermentation, and the fermentation consumed the functional group with simpler structure such as aliphatic chain hydrocarbon of fulvic acid while the structure with a higher degree of aromatization and conjugate cannot be consumed. When conducting acid precipitation with different liquid acids, the yield of fulvic acid was the highest through acid precipitation with phosphoric acid. The fulvic acid obtained through acid precipitation with nitric acid has a higher content, more benzene rings, and the highest degree of aromatization.