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ABSTRACT Nowadays, there is increasing interest in natural antioxidants from food by-products. Astaxanthin is a potent antioxidant and one of the major carotenoids in crustaceans and salmonids. An ultra-high pressure liquid chromatographic method was developed and validated for the determination of astaxanthin in shrimp by-products, and its migration from new packaging materials to food simulants was also studied. The method uses an UPLC® BEH guard-column (2.1 × 5 mm, 1.7 µm particle size) and an UPLC® BEH analytical column (2.1 × 50 mm, 1.7 µm particle size). Chromatographic separation was achieved using a programmed gradient mobile phase consisting of (A) acetonitrile-methanol (containing 0.05 m ammonium acetate)-dichloromethane (75:20:5, v/v/v) and (B) ultrapure water. This method was evaluated with respect to validation parameters such as linearity, precision, limit of detection, limit of quantification and recovery. Low-density polyethylene films were prepared with different amounts of the lipid fraction of fermented shrimp waste by extrusion, and migration was evaluated into food simulants (isooctane and ethanol 95%, v/v). Migration was not detected under the tested conditions. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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ABSTRACT Whole white corn was ground, and lime, water and xylanase enzyme (0.05, 0.075 or 0.1% w/w) were added. Blends were extruded, dried and ground to obtain extruded nixtamalized corn flour (ENCF), which was used to make tortillas. The water absorption index and water absorption capacity (WAC) of the corn flours were determined. Viscoelastic characteristics were determined in corn masa made of extruded nixtamalized flours. Tortillas were made, and determination of moisture content and texture (cutting force and rollability) during storage was carried out. Furthermore, tortillas were evaluated by sensory evaluation. The flours containing xylanase showed significantly higher WAC ( P < 0.05) than the flour without xylanase. The viscoelastic parameters were increased by adding xylanase, which also decreased the hardening and increased the flexibility of tortillas. Corn tortillas with 0.075 and 0.1% xylanase concentrations were 15% softer than the control (without xylanase). Additionally, corn tortillas made with ENCF containing the xylanase enzyme had acceptable organoleptic characteristics. PRACTICAL APPLICATIONS The extrusion process permits the use of whole corn, lowers processing costs and reduces contaminant effluents (cooking liquor). The addition of the xylanase enzyme during extrusion partially hydrolyzes the main cellular components of the dietary fiber, the arabinoxylans, and modifies its rheological properties. Softening of most corn pericarp layers is essential in forming masa that has acceptable sheeting characteristics, which is important during the tortilla-making process. [ABSTRACT FROM AUTHOR]

Antimicrobial films for food packaging applications have received increasing attention from the industry in recent years. Due to their exceptional properties, such as non-toxicity, biodegradability, antimicrobial characteristics, and biocompatibility, chitosan has proven useful for the development of active materials. This review aims to provide anoverview of the main techniques used for the characterization of chitin and chitosan, including Fourier transforminfrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, UV spectrophotometry, viscosimetry, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), titrations, scanning electron microscopy (SEM) and size exclusion chromatography (SEC) among others. In addition, the main applications of the polymer in food packaging are also reported. En los últimos años los films antimicrobianos han recibido una gran atención por parte de la industria para su aplicación en el envasado alimentario. Debido a sus excepcionales propiedades, no-tóxico, biodegradable, características antimicrobianas y biocompatible, el quitosano ha demostrado ser útil para el desarrollo de materiales activos. Este artículo de revisión tiene por objeto proporcionar una visión general de las principales técnicas usadas para la caracterización de quitina y quitosano incluidas la espectroscopia infrarroja (FTIR), la espectroscopia RMN de 1H y 13C, la espectrofotometría UV, viscosimetría, análisis elemental, difracción de rayos-X (XRD), análisis termogravimétrico (TGA), titulaciones, microscopía electrónica de barrido (SEM) y cromatografía de exclusión por tamaños (SEC)entre otras. Además, se describen las principales aplicaciones del polímero en el envasado de los alimentos. [ABSTRACT FROM AUTHOR]

The effects of solid state fermentation (SSF) on physicochemical, nutritional and antioxidant properties of common bean flour were studied. SSF increased protein content (21.7%) and decreased lipids (-38.4%), carbohydrates (-3.5%) and phytic acid (-58.3%). Fermented (tempeh) flour showed higher dispersability, lower water solubility index and pH than unfermented flour. Fermentation also increased an average of 0.21 g/100 g protein, six of the essential amino acids (EAAs), including total sulfur (Met + Cys), the limiting EAAs in unfermented flour (score = 0.91); Lys and Trp decreased 0.21 and 0.09 g/100 g protein, respectively. SSF improved the in vitro protein digestibility and the calculated protein efficiency ratio. Tempeh flour had 2.2-fold more phenolics than the bean flour and exhibited antiradical activity (43%) and antioxidant activity (38%) correlated with total phenolics content. Common bean tempeh flour may be considered for the fortification of widely consumed legume-based food products and also for the prevention of pathologies associated with oxidative stress. [ABSTRACT FROM AUTHOR]

Whole white corn was ground, and lime, water and xanthan gum (XG, 0.5% w/w), carboxymethylcellulose (CMC, 0.5% w/w), guar gum (GG, 0.5% w/w) or a gums mix (XG, 0.25% w/w; CMC, 0.15% w/w; GG, 0.10% w/w) were added. Blends were extruded, dried and ground to obtain nixtamalized corn flour (ENCF), and they were used to make tortillas. The particle size distribution, particle size index, water absorption capacity (WAC) and water absorption index (WAI) were determined in flour; moisture content and viscoelastic characteristics (G′, G′′, tan δ) were determined in corn masa; tortillas were made, and texture (cutting force and rollability) and sensory evaluation were carried out. ENCF with XG and gums mix had the highest WAC, and tortillas were softer (33%) than tortillas from ENCF without gums. Corn masa viscoelasticity (tan δ) correlated negatively with tortilla firmness (r = − 0.84). Corn tortillas made with XG and gums mix had acceptable organoleptic characteristics. PRACTICAL APPLICATION The extrusion process allows the using of the whole corn to make tortillas and reduce processing costs and the contaminant effluents (cooking liquor). The addition of a mix of gums during extrusion makes the corn masa retain more water and modify its rheological properties, improving masa handling characteristics and tortilla textural quality. The evaluation of masa viscoelasticity with the dynamic method makes it possible to differentiate corn masas and to select the best treatments. [ABSTRACT FROM AUTHOR]

A simple and specific analytical method was developed and tested for the determination of sulforaphane in broccoli by-products. The method includes the optimization of the conversion of glucoraphanin to sulforaphane, followed by purification of extracts using solid-phase extraction and high-performance liquid chromatography (HPLC) analysis. The response surface methodology was used to find optimum conditions for the preparation and purification procedure. Chromatographic conditions for reversed-phase HPLC with UV photodiode array detection were as follows: column, Exil ODS C18, 25 × 0.46 cm, 5 μm; column temperature, 36°C; mobile phase, a 30 : 70 (v/v) mixture of acetonitrile:water; flow rate, 0.6 mL/min. The detection wavelength was UV 202 nm. Under these conditions, excellent linearity was obtained ( r2 = 1), and the overall recovery was 97.5 and 98.1% for fresh florets and lyophilized florets, respectively. The precision results showed that the relative standard deviation of the repeatability for florets fresh and lyophilized was 3.0 and 4.0%, respectively. Sulforaphane contents were determined in the edible portion of fresh broccoli, and broccoli crop remains. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper presents a high performance liquid chromatography (HPLC) method for the determination of riboflavin and free aromatic amino acids. To determine riboflavin, the method includes an acid hydrolysis (HCl 0.1 N) followed by an enzymatic digestion and a protein precipitation with trichloroacetic acid. An analytical column, Chrom SEP SS C18 5 µm (4.6 mm × 150 mm) was used with an isocratic flow using a mobile phase consisting of 5 mM ammonium acetate-methanol (72:28, vv-1), at a flow rate of 1.0 mL min-1 to 28°C. The method showed adequate linearity, repeatability, reproducibility, accuracy, and limits of detection. The method was used to quantify the cited analytes in three different forms of hydrolysate obtained from fermented shrimp remnants. [ABSTRACT FROM AUTHOR]

Abstract: Protein hydrolysates were prepared through lactic acid fermentation of the inedible portions of shrimp (cephalothorax and exoskeleton), the by-products of shrimp processing operations. The protein-rich liquid hydrolysate was further processed into a concentrated paste via vacuum evaporation at 80°C or was also processed into a dry powder using a spray drying method at 180°C/140°C (inlet/outlet temp). The laboratory compared the composition of the three forms of shrimp protein hydrolysates. The protein and ash content of the hydrolysates ranged from 8.43±0.22 to 46.73±1.29 and 2.03±0.52 to 8.25±0.14g/100g of wet weight. All the samples were analyzed for fifteen amino acids; the powder form was analyzed for colour, microbial content, and for heavy metal occurrence. The shrimp by-products were successfully converted into micro-nutrient by-products rich in amino acids for potential recommendations in the supplementation of animal and human diets. [Copyright &y& Elsevier]

The objective of this research was to study the biochemical composition and physicochemical properties of three different flours prepared from broccoli crop remains. Florets, leaves and stalks of broccoli were dried at 60 degrees C, and the flours obtained were analysed for proximate composition, amino acid profile, fatty acid composition, and physicochemical properties. The florets flour showed the highest protein content (22.41 g/100 g dry weight); ash was higher in leaves flour (14.67 g/100 g dry weight), and the lipid content was similar in the flours of leaves and stalks. The stalks flour had high crude fibre content and low protein content. All flours presented a high water absorption index. Tyrosine, aspartic acid, glutamic acid, proline and valine were found in larger concentration. The most abundant fatty acids in the lipids were linolenic acid (C18:3n3), palmitic acid (C16:0) and linoleic acid (C18:2n6). Broccoli flours prepared in this study are good source of nutrients and could be utilized as dietary supplements. [ABSTRACT FROM AUTHOR]

In the present study, a simple and rapid reversed-phase HPLC method for the determination of astaxanthin in shrimp waste hydrolysate has been developed and validated. The analytical procedure involves the direct extraction of astaxanthin from the lipid fraction with methanol. The analytical column, SS Exil ODS, was operated at 25C. The mobile phase consisted of a mixture of water:methanol:dichloromethane:acetonitrile (4.5:28:22:45.5 v/v/v/v) at a flow rate of 1.0 mL/min. Detection and identification were performed using a photodiode array detector ( λdetection = 476 nm). The proposed HPLC method showed adequate linearity, repeatability and accuracy. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The total lipid, protein, ash and individual fatty acid contents of edible seaweeds that had been canned (Saccorhiza polyschides and Himanthalia elongata) or dried (H. elongata, Laminaria ochroleuca, Undaria pinnatifida, Palmaria sp. and Porphyra sp.) were determined (fatty acids by gas chromatography). Total lipid content ranged from 0.70±0.09 to 1.80±0.14 g/(100 g dry weight). The four most abundant fatty acids were C16:0, C18:1ω9, C20:4ω6 and C20:5ω3. Unsaturated fatty acids predominated in all the brown seaweeds studied, and saturated fatty acids in the red seaweeds, but both groups are balanced sources of ω3 and ω6 acids. Ash content ranged from 19.07±0.61 to 34.00±0.11 g/(100 g dry weight), and protein content from 5.46±0.16 to 24.11±1.03 g/(100 g dry weight). These protein, ash and ω3 and ω6 fatty acid contents show that processing (canning or drying) leaves these seaweeds with substantial nutritional value. [Copyright &y& Elsevier]

This study presents an HPLC method for the quantification of sterols in edible seaweeds. Sterols were identified by HPLC/mass spectrometry (HPLC-MS) in positive APCI mode. The samples were saponified by refluxing with 1 m ethanolic KOH, and the non-saponifiable fraction was extracted with hexane. Sterols were quantified by HPLC with UV detection (HPLC-UV), on a 15 × 0.4 cm Kromasil 100 C18 5 µm column (mobile phase 30:70 v/v methanol:acetonitrile; flow rate 1.2 mL/min; column temperature 30°C; detection wavelength 205 nm). Method repeatability for fucosterol was good (coefficient of variation 2.4%). Sterol contents were determined in canned or dried brown seaweeds ( Himanthalia elongata, Undaria pinnatifida, Laminaria ochroleuca) and red seaweeds ( Palmaria sp., Porphyra sp.). The predominant sterol was fucosterol in brown seaweeds (83-97% of total sterol content; 662-2320 µg/g dry weight), and desmosterol in red seaweeds (87-93% of total sterol content; 187-337 µg/g dry weight). Copyright © 2004 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A high-performance liquid chromatographic (HPLC) method is described for determination of the ratio of β- d-mannuronic acid to α- l-guluronic acid (M/G ratio) in dietary fibre of edible seaweeds. Total dietary fibre (TDF) content was determined gravimetrically. The TDF fraction was hydrolysed with 12 m and 1 m H2SO4, then neutralized with AG 4 × 4 resin. The uronic acids were separated in a Tracer Extrasil SAX 5 µm column (25 cm × 4 mm) at 35°C, with 2 m m KH2PO4 containing 5% methanol as mobile phase at a flow rate of 1.5 mL/min. The detection wavelength was UV 210 nm. The chromatographic identifications of β- d-mannuronic acid and α- l-guluronic acid were confirmed by liquid chromatography-mass spectrometry (LC-MS). The method precision was 1.4% for β- d-mannuronic acid and 3.5% for α- l-guluronic acid. The method was used to determine M/G ratio in canned seaweeds ( Saccorhiza polyschides and Himanthalia elongata) and in dried seaweeds ( H. elongata, Laminaria ochroleuca, Undaria pinnatifida, Palmaria sp. and Porphyra sp.). Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is used as an additive in polyvinyl chloride (PVC) products, including stretch films used for food packaging. The BPA contents were investigated of several brands of stretch film bought locally but marketed internationally or throughout Spain and which were presumably produced at different manufacturing plants. Their major components were identified by FTIR (Fourier Transform Infrared Spectrometry) and horizontal attenuated total reflectance, and the migration of BPA from these materials into the standard European Union food simulants was determined by high-performance liquid chromatography (HPLC) using both fluorescence (FL) and ultraviolet (UV) detection, the identity of the analyte being confirmed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The two HPLC detection methods had different detection limits (30 μg l[SUP-1] for UV, 3 μg l[SUP-1] for FL), but afforded virtually identical BPA determinations for the samples tested. BPA contents ranging from 40 to 100 mg kg[SUP-1] were found in three of the five PVC-based films analysed, and a content of 500 mg kg[SUP-1] was found in a fourth; for these determinations, extraction into acetonitrile was used. In standard tests of migration into water, 3% acetic acid and olive oil over 10 days at 40°C, migration from a given film was in all cases greatest into olive oil. Migration from the films with non-zero BPA contents ranged from 3 to 31 μg dm[SUP-2], values higher than those reported for many other food-contact materials, but lower than the European Union specific migration limit for BPA. PVC stretch film nevertheless may make a significant contribution to contamination of foodstuffs by BPA, and should be taken into account in estimating BPA intake or exposure to this substance. [ABSTRACT FROM AUTHOR]

In this work the proximal analysis, physicochemical characterization, fatty acid profile and astaxanthin content of pigmented oil obtained by fermentation shrimp heads are presented. Lipids are the major components in the oil (95%). The saponification number is 178.62 mg KOH/g, iodine value 139.8 cg iodine/g, and the peroxide value was not detected. Density and viscosity were 0.92 mg/ml and 64 centipoises, respectively. The highest contents of fatty acids were linoleic (C18:2n6), oleic (C18:1n9) and palmitic (C16:0). Eicosapentaenoic acid (C20:5n3, EPA) and docosahexaenoic acid (C22:6n3, DHA) account for 9% of the total. The content of astaxanthin was 2.72 mg/g dry weight. The pigmented oil is a dietary source of nutrients with high value such as astaxanthin. [ABSTRACT FROM AUTHOR]

Chitosan (CAS n. 9012-76-4) is a natural polysaccharide obtained by the partial deacetylation of chitin. It is a linear polymer of b (1-4) 2-acetamido-2-deoxy-D-glucose and 2-amino-2-deoxy-D-glucose in different proportions. Chitin is the most abundant polysaccharide after cellulose and the main source is the shells of crustaceans. It has been demonstrated that some important properties are directly related to the antimicrobial activity of chitosan. Some of these properties are the molecular weight (Mw), the degree of polymerisation (DP) and the degree of deacetylation (DD). In this work several analytical techniques (FTIR (Fourier-transform Infrared Spectroscopy), NMR (Nuclear Magnetic Resonance Spectroscopy) and SEM (Scanning Electron Microscopy)) were attempted to characterize two different samples obtained from shrimp waste. It can be concluded that sample 1 should be more suitable to be added as an active agent to a film. [ABSTRACT FROM AUTHOR]

The possibility of using the lipid fraction from fermented shrimp waste as a source of natural a-tocopherol to produce packaging with antioxidant properties was evaluated. A fast reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method coupled with a diode array detector was developed to determine α-tocopherol in the lipid fraction of shrimp waste. The α-tocopherol level found using acetonitrile as extraction solvent was 50.5 mg/100 g sample, indicating. [ABSTRACT FROM AUTHOR]