Quantification of Organic Acids in Fermented Shrimp Waste by HPLC

This work describes a simple, rapid, and reliable HPLC method for the determination of organic acids in fermented shrimp waste. Lactic, acetic and citric acids were quantified by HPLC with UV detection, on a 250×4.6 mm Extrasil ODS 5-μm column, mobile phase was ultrapure water adjusted with metaphosphoric acid to pH=2.1, flow rate 0.6 mL/min, column temperature 30 °C, and detection wavelength 210 nm. Under these conditions, the recovery (97.5 %) and the method repeatability (RSD=6.2 %) for lactic acid were of satisfying quality. Organic acids can preserve the quality and nutritive value of fermented shrimp waste

Određivanje masenog udjela organskih kiselina u fermentiranim otpacima od škampa HPLC metodom

This work describes a simple, rapid, and reliable HPLC method for the determination of organic acids in fermented shrimp waste. Lactic, acetic and citric acids were quantified by HPLC with UV detection, on a 250×4.6 mm Extrasil ODS 5-μm column, mobile phase was ultrapure water adjusted with metaphosphoric acid to pH=2.1, flow rate 0.6 mL/min, column temperature 30 °C, and detection wavelength 210 nm. Under these conditions, the recovery (97.5 %) and the method repeatability (RSD=6.2 %) for lactic acid were of satisfying quality. Organic acids can preserve the quality and nutritive value of fermented shrimp waste.U ovom je radu opisana brza i pouzdana metoda određivanja masenog udjela organskih kiselina u fermentiranim otpacima od škampa. Određen je maseni udio mliječne, octene i limunske kiseline HPLC metodom s UV detekcijom na koloni Extrasil ODS 5 μm, 250×4,6 mm (mobilna faza: ultračista voda čija je pH-vrijednost prilagođena pomoću metafosforne kiseline na pH=2,1, brzina protoka 0,6 mL/min, temperatura kolone 30 °C, valna duljina detekcije 210 nm). U tim se uvjetima postiglo najbolje iskorištenje mliječne kiseline (97,5 %) i ponovljivost metode (6,2 %). Dokazano je da organske kiseline mogu sačuvati kakvoću i hranjivu vrijednost fermentiranih otpadaka od škampa

Određivanje masenog udjela organskih kiselina u fermentiranim otpacima od škampa HPLC metodom

This work describes a simple, rapid, and reliable HPLC method for the determination of organic acids in fermented shrimp waste. Lactic, acetic and citric acids were quantified by HPLC with UV detection, on a 250×4.6 mm Extrasil ODS 5-μm column, mobile phase was ultrapure water adjusted with metaphosphoric acid to pH=2.1, flow rate 0.6 mL/min, column temperature 30 °C, and detection wavelength 210 nm. Under these conditions, the recovery (97.5 %) and the method repeatability (RSD=6.2 %) for lactic acid were of satisfying quality. Organic acids can preserve the quality and nutritive value of fermented shrimp waste.U ovom je radu opisana brza i pouzdana metoda određivanja masenog udjela organskih kiselina u fermentiranim otpacima od škampa. Određen je maseni udio mliječne, octene i limunske kiseline HPLC metodom s UV detekcijom na koloni Extrasil ODS 5 μm, 250×4,6 mm (mobilna faza: ultračista voda čija je pH-vrijednost prilagođena pomoću metafosforne kiseline na pH=2,1, brzina protoka 0,6 mL/min, temperatura kolone 30 °C, valna duljina detekcije 210 nm). U tim se uvjetima postiglo najbolje iskorištenje mliječne kiseline (97,5 %) i ponovljivost metode (6,2 %). Dokazano je da organske kiseline mogu sačuvati kakvoću i hranjivu vrijednost fermentiranih otpadaka od škampa

The structural characteristics of starches and their functional properties

Starch is composed of amylose and amylopectin and deposited as granules of different sizes and shapes with semi-crystalline and amorphous concentric layers that show the ‘maltese cross’. Starches from different sources show variable chemical composition as well as the structure of their components that are involved in thermal properties. Amylose, lipids, phosphorylated residues and long lateral chain amylopectin interact among them avoiding water uptake. In contrast, high amylopectin contents, especially with short lateral chains, allow hydration via hydrogen bonds to form gels with the tendency to retrogradation. Smaller starch granules have a larger superficial area, surface pores, and channels that enhance water uptake. High hydration increases the swelling, viscosity, and gelatinization ability of starch granules. The knowledge of those properties allows the selection of the most appropriate starch for a specific end use. This review discusses the relationship between the physicochemical composition of the starch and their rheological properties

Emerging Technologies for Prolonging Fresh-Cut Fruits’ Quality and Safety during Storage

Fresh-cut fruits have been in great demand by consumers owing to the convenience of buying them in shopping centers as ready-to-eat products, and various advantages, such as the fact that they are healthy and fresh products. However, their shelf lives are brief due to their physiological changes and maturation. Therefore, this review includes information from the physicochemical, microbiological, nutritional, and sensory points of view on the deterioration mechanisms of fresh-cut fruits. In addition, updated information is presented on the different emerging technologies, such as active packaging (edible films, coatings, and modified atmospheres), natural preservatives (antioxidants and antimicrobials), and physical treatments (high hydrostatic pressure, UV-C radiation, and ozone). The benefits and disadvantages of each of these technologies and the ease of their applications are discussed. Having alternatives to preserve fresh-cut fruit is essential both for the consumer and the merchant, since the consumer could then obtain a high-quality product maintaining all its properties without causing any damage, and the merchant would receive economic benefits by having more time to sell the product

Lipidic compounds from the muscle of white shrimp (Litopenaeus vannamei): chemical structure and effect on the proliferation and morphology of human cancer cell lines

9 pages, 3 figures, 2 tables.-- This is an Open Access article distributed under the terms of the Creative Commons Attribution LicenseCancer represents the second leading cause of death worldwide, therefore, the search for chemoprotective agents is on the rise. The muscle of white shrimp (Litopenaeus vannamei) is one of the species analyzed as it has been reported as a source of compounds with antiproliferative activity. The aim of this study was to evaluate the effect of shrimp muscle-isolated compounds on cell proliferation and morphology of human cancer cell lines. The muscle underwent a process of extraction and fractionation of compounds; their effect on cell viability assays (MTT) on lung adenocarcinoma (A549), prostate carcinoma (22 Rv-1), invasive breast adenocarcinoma (MDA MB 231), colon carcinoma (HTC 116), cervix adenocarcinoma (HeLa) and non-cancerous retinal cells (ARPE-19) was measured. Morphological changes were observed using fluorescence microscopy and chemical structure data was obtained using nuclear magnetic resonance. Fraction named C5 showed the highest antiproliferative activity on HCT-116 and MDA-MB-231, without significantly affecting the control cells. Subfractions C5-3 and C5-4 presented significant antiproliferative potential in MDA-MB-231; this cell line showed morphological changes that could be related to apoptosis, and spectroscopic analysis revealed the presence of b-carotene and eicosapentaenoic acid in C5, nevertheless, further studies are needed to determine the effect of each compoundPeer reviewe

Comparative kinetic characterization of the activity of glycosylated and non-glycosylated trypsin-like serine protease isolated from adults of Rhyzopertha dominica (Coleoptera: Bostrichidae) reared on the grain of three different cultivars of wheat

Rhyzopertha dominica is a pest that uses trypsin-like serine protease enzymes to hydrolyse the proteins in the cereal grains on which it feeds. The present study reveals for the first time that that there are both glycosylated and non-glycosylated serine proteases. The progeny of R. dominica reared on the grain three varieties of wheat were used to fractionate their trypsin-like serine proteases using Concanavalin A affinity chromatography. The albumin fractions from the wheat cultivars used in this study were subjected to size exclusion chromatography to fractionate the albumin inhibitors that are highly specific for the serine protease activity of R. dominica. Kinetic and thermodynamic assays were used to differentiate both types of enzymes. In general, the catalytic efficiency values Vmax/Km for glycosylated proteases were higher, indicating that glycosylation increases the affinity for the substrate. Inhibition assays using wheat albumins revealed that the glycosylated enzymes had higher Ki values, indicating a low affinity for the inhibitors than the non-glycosylated enzymes. Thermodynamic analysis indicates that glycosylation increases the activation energy Ea improving the serine proteases' catalysis. Thus it is likely that R. dominica uses glycosylated proteases in order to optimize the hydrolysis of cereal proteins and nullify the action of wheat grain protease inhibitors and increase its chances of survival