scholarly journals Fermentable carbohydrate metabolism in maguey mezcalero potosino (Agave salmiana): HPLC characterization and evaluation

2021 ◽  
Vol 49 (1) ◽  
pp. 12154
Author(s):  
Christian MICHEL-CUELLO ◽  
Noé AGUILAR-RIVERA ◽  
Cristian LÓPEZ-PALACIOS ◽  
Juan F. CÁRDENAS-GONZÁLEZ

The maguey mezcalero potosino (Agave salmiana) is a natural resource of great regional importance, used for the manufacture of mezcal and other alcoholic beverages by fermentation of simple sugars and sugars released by fructans hydrolysis. For this, only the stem and base of leaves is used, which results on wasting the other sections that represent up to 40% of weight of the complete plant. The objective of this study was to identify and quantify the fermentable carbohydrates present in raw and hydrolysed juices of the stem and four sections of the whole leaves (base, neck, wings and apex) of maguey plants with representative specimens of three stages of maturity with industrial importance. For carbohydrate characterization, high resolution liquid chromatography (HLPC) was used. The sugars found as fructose, glucose, sucrose, xylose and maltose coincide with those identified in other Agave species, significant differences are observed depending on the section and the state of maturity of the plant, the sugar concentration in the discarded sections of the plant (fructose: 5.79 – 4.80 mg mL-1) are considerable and statistically similar to those found in the stem (fructose: 2.49 mg mL-1) and the base of the leaf (fructose: 3.16 mg mL-1) (structure used in the mezcal production process). The results obtained can promote the integral use of the plant and diversification towards other industries such as pharmaceuticals, biofuels or foods.

Author(s):  
G.Y. Fan ◽  
O.L. Krivanek

Full alignment of a high resolution electron microscope (HREM) requires five parameters to be optimized: the illumination angle (beam tilt) x and y, defocus, and astigmatism magnitude and orientation. Because neither voltage nor current centering lead to the correct illumination angle, all the adjustments must be done on the basis of observing contrast changes in a recorded image. The full alignment can be carried out by a computer which is connected to a suitable image pick-up device and is able to control the microscope, sometimes with greater precision and speed than even a skilled operator can achieve. Two approaches to computer-controlled (automatic) alignment have been investigated. The first is based on measuring the dependence of the overall contrast in the image of a thin amorphous specimen on the relevant parameters, the other on measuring the image shift. Here we report on our progress in developing a new method, which makes use of the full information contained in a computed diffractogram.


2019 ◽  
Author(s):  
Buddhika Dorakumbura ◽  
Francesco Busetti ◽  
Simon Lewis

<p>Transformation of squalene and its by-products in fingermarks over time under different storage conditions (light, dark and underwater) was examined through ultrahigh-pressure liquid chromatography high resolution accurate mass Orbitrap™ mass spectrometry. Complications of assessing fingermark compositional variation over time using multiple samples with varying initial compositions were elucidated and a more rational approach was successfully demonstrated. Squalene was detected in all fresh natural fingermarks and the amount ranged between 0.20 to 11.32 μg/5 fingertips. A notable difference in the transformation of squalene was observed with different storage conditions, where a dark aquatic environment accelerated degradation of squalene compared to dark but dry conditions. Squalene monohydroperoxide was extremely short-lived in natural deposits while the amount of squalene epoxide was still increasing relative to the initial amount, after ageing under dark and aquatic conditions for up to 7 days. Some oxidation by-products of cholesterol were also tentatively identified, which exhibited a growth over time against their initial concentration under any of the storage condition tested. These by-products, therefore, show potential as biomarkers for targeted visualisation of aged deposits.</p>


Author(s):  
Nurida Finahari

The art of chisel mask is developed in Tumpang Malang area as part of dance costume fairs, puppet show andcultural ritual, although in its development, this mask sculpture is also sold and become a tourism commodity. The potentialsales of mask sculptures is increasing, especially because of the demanders are foreign tourists, cultural enthusiasts andcomponent of tourism activities. That is, Topeng Malangan has the potential to be developed as an export commodity. Thesales system is still limited to cultural events or when there is a visit of education and tourism to the arts-padepokan. Thisprompted some people around the padepokan to start a home industry to meet the availability of the mask. In general, theproblems encountered by the craftsmen are (1) availability of raw materials, especially for suitable wood species, (2)production equipment, especially for pre-carving process and preservation of product, (3) there is no standard marketingscheme, (4) does not have a business management system, and (5) highly skilled craftsmen are still very limited. The solutionsoffered are divided into three stages: (1) technological strengthening, including strengthening production process technologyand increasing the number of craftsmen; (2) establishing business management; and (3) establishing trademarks, copyrightsand product marketing expansions


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