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Flash pasteurization, also called "high-temperature short-time" (HTST) processing, is a method of heat pasteurization of perishable beverages like fruit and vegetable juices, beer, wine, and some dairy products such as milk. Compared with other pasteurization processes, it maintains color and flavor better, but some cheeses were found to have ...
The IUPAC acknowledges the three divergent definitions of carbonium ion and urges care in the usage of this term. For the remainder of this article, the term carbonium ion will be used in this latter restricted sense, while non-classical carbocation will be used to refer to any carbocation with C–C and/or C–H σ-bonds delocalized by bridging.
Pasteurized milk in Japan A 1912 Chicago Department of Health poster explains household pasteurization to mothers.. In food processing, pasteurization (also pasteurisation) is a process of food preservation in which packaged foods (e.g., milk and fruit juices) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life.
The alcohol is protonated, the H 2 O group formed leaves, forming a carbocation, and the nucleophile Cl − (which is present in excess) readily attacks the carbocation, forming the chloroalkane. Tertiary alcohols react immediately with Lucas reagent as evidenced by turbidity owing to the low solubility of the organic chloride in the aqueous ...
Typical route for alkylation of benzene with ethylene and ZSM-5 as a heterogeneous catalyst. Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene (or their equivalents).
Here, the difference in pK b between the base and the enolate is so large that the reaction is essentially irreversible, so the equilibration leading to the thermodynamic product is likely a proton exchange occurring during the addition between the kinetic enolate and as-yet-unreacted ketone. An inverse addition (adding ketone to the base) with ...
It may either destabilize the cation by drawing even more electron density from the carbon or stabilizing by contributing more electron density. The carbocation positive charge can be relieved by an unsaturated carbon-based or heteroatomic substituent through p-donation and/or C-H hyperconjugation by methylene/methyl substituents. In addition ...
Examples of hurdles in a food system are high temperature during processing, low temperature during storage, increasing the acidity, lowering the water activity or redox potential, and the presence of preservatives or biopreservatives. According to the type of pathogens and how risky they are, the intensity of the hurdles can be adjusted ...