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Household and Personal Care Products: Cleaning up and Looking Good
Published in Richard J. Sundberg, The Chemical Century, 2017
The reactions used to synthesize alkyl polyglycosides go back to the carbohydrate pioneer Emil Fischer, who reported examples in 1911. Patents for use as detergents were issued in Germany as early as 1934. Although Rohm & Haas and BASF marketed such products for specialized uses in the 1970s, the introduction into laundry and dishwashing detergents was led by Henkel, which opened plants in the United States and Germany in 1992 and 1995, respectively. The process is based on the same methodology used by Fischer and involves introduction of a long-chain alcohol into the acetal (anomeric) position of glucose. The materials can be made either from monomeric glucose or polymeric forms such as starch or glucose syrup (see Section 9.2.1). When the starting material is of high MW, a preliminary partial depolymerization/acetalization is carried out using a lower MW alcohol such as butanol. The alcohol groups in the alkyl polyglycosides are mainly the C12 and C14 compounds. The commercial product consists of a mixture of mono- (50–65%), di- (~20%), tri- (~10%), tetra- (5–10%) and higher (2–5%) saccharides. The precise composition is determined by the ratio of glucose to alcohol and the conditions used for the reaction. The alkyl glycosides can be considered to be completely renewable, although the long-chain alcohols can be obtained from either petrochemicals or oleochemicals. They are readily biodegradable, nontoxic and nonirritant. They thus have an especially favorable environmental profile among the major surfactants.
Effects of environmental temperature and relative humidity on the rehydration of dried pistachios
Published in Drying Technology, 2019
In the literature, there are many studies reported about food processing. Some of these are about investigating the moisture sorption, rehydration, drying, and water activity (aw) of foods. Abdullah et al.[21] determined the starch-based foods, which must be stored at water activity(aw) levels or not more than 0.65. Ayranci et al.[22] reported moisture sorption isotherms of dried apricots, fig, and raisin at 20 °C and 36 °C and experimentally showed 25 °C that moisture content decreases in the water activity(aw) region below 0.6. Ansari et al.[23] presented a model to estimate the effect of glucose syrup on the moisture sorption isotherms of figs and illustrated that figs with glucose syrup provides with better absorbing the water at a specific water activity (aw). Ansari et al.[24] studied modeling rehydration behavior of dried figs. Ansari showed that using high temperatures for rehydration of the figs results in an elevation in both water adsorption rates and amount of water absorbed. Goula and Adamopoulos[25] investigated the rehydration kinetics of dried tomato and examined the feasibility of modeling the rehydration process. Yanniotis and Zarmboutis[26] observed adsorption and desorption of pistachio nuts at 15 °C, 25 °C, and 40 °C by gravimetric technique. Krokida and Philippopoulos[27] presented a first-order kinetic, which could describe the water uptake during the rehydration of fruits and vegetables. They examined the influence of temperature on the rehydration constant and the equilibrium moisture content after rehydration.
Application of fuzzy control in the evaporation stage of a first- and second-generation sugarcane ethanol biorefinery
Published in Chemical Engineering Communications, 2023
E. Y. Emori, M. A. S. S. Ravagnani, C. B. B. Costa
On a four-effect evaporator of a first- and second-generation sugarcane biorefinery, a feedforward fuzzy control scheme is proposed and implemented. The objective is to control the sugar mass concentration through the feed steam and splitter fraction value manipulation. The process is simulated by a phenomenological dynamic model implemented in the noncommercial EMSO process simulator. Also, the thermodynamic database VRTherm is coupled to the simulation to provide physical properties. To test the control system efficiency, the sugarcane juice volumetric flow rate and concentration are disturbed simultaneously to different magnitudes. The glucose syrup volumetric flow rate is also disturbed.
The impact of using polyols as osmotic agents on mass exchange during osmotic dehydration and their content in osmodehydrated and dried apples
Published in Drying Technology, 2020
Hanna Kowalska, Łukasz Woźniak, Ewelina Masiarz, Alicja Stelmach, Agnieszka Salamon, Jolanta Kowalska, Dariusz Piotrowski, Agata Marzec
Osmotic dehydration (OD) is the process of partial water removal through direct contact of plant materials with a hypertonic solution.[7,8] Multiple chemical and physical changes do occur during this.[8] They are triggered by the simultaneous removal of water and substances dissolved in it and by the penetration of the osmotic substance into the dehydrated material.[9] A novel variant of OD (named postdipping dehydration) where a material is dipped in a salt or sugar solution for a very short time followed by simple exposure to ambient conditions was explored with the aim of lowering water content of potato slices but at the same time not gain a high level of sugar/salt.[10] Even a moderate process temperature (40–50 °C) can minimize undesirable changes in color and aroma loss in dehydrated fruit.[8] Therefore, it is sometimes not required to add sulfur compounds (i.e. sulfur dioxide) used as antioxidants to protect fruit against oxidative and enzymatic discoloration.[11] Such osmotic substances as sucrose, glucose syrup, corn syrup and glucose, sorbitol, fructo-oligosaccharides[12] as well as juice concentrates are typically used for dehydration.[8,9,11,13,14] Alternative substances, such as polyols, are quite rarely used in this process.[6,11,15,16]