Biosynthesis of phenolic antioxidants in carrot tissue increases with wounding intensity

Biosynthesis of phenolic antioxidants in three carrots cultivars (Navajo, Legend and Choctaw) were studied under different wounding intensities (A/W) during storage. Generated A/W of 4.2, 6.0 and 23.5 cm²/g, corresponded to slices, pies, and shreds, respectively. Soluble phenolics, antioxidant capacity (AOX), and PAL activity increased with A/W for all cultivars. Intense wounding (23.5 cm²/g) induced an ∼2.5- and ∼12.4-fold increase in soluble phenolics and AOX, respectively, after 4 days compared to whole carrots. Wounding induced the synthesis of mainly chlorogenic acid (5-CQA) and 3,5-dicaffeoylquinic acid. A higher proportion of 5-CQA in the phenolic mixture was responsible for an increasing specific AOX (809 and 1619 μg Trolox/mg phenolics for whole carrots and shreds, respectively, for Choctaw cultivar). Wounded carrots can be promoted as an inexpensive rich source of phenolic antioxidants for the regular diet. By simply increasing wounding stress intensity it is possible to enhance the biosynthesis of phenolic antioxidants.     

Validation of the performance of a GMO multiplex screening assay based on microarray detection

A new screening method for the detection and identification of GMO, based on the use of multiplex PCR followed by microarray, has been developed and is presented. The technology is based on the identification of quite ubiquitous GMO genetic target elements first amplified by PCR, followed by direct hybridisation of the amplicons on a predefined microarray (DualChip^® GMO, Eppendorf, Germany). The validation was performed within the framework of a European project (Co-Extra, contract no 007158) and in collaboration with 12 laboratories specialised in GMO detection. The present study reports the strategy and the results of an ISO complying validation of the method carried out through an inter-laboratory study. Sets of blind samples were provided consisting of DNA reference materials covering all the elements detectable by specific probes present on the array. The GMO concentrations varied from 1% down to 0.045%. In addition, a mixture of two GMO events (0.1% RRS diluted in 100% TOPAS19/2) was incorporated in the study to test the robustness of the assay in extreme conditions. Data were processed according to ISO 5725 standard. The method was evaluated with predefined performance criteria with respect to the EC CRL method acceptance criteria. The overall method performance met the acceptance criteria; in particular, the results showed that the method is suitable for the detection of the different target elements at 0.1% concentration of GMO with a 95% accuracy rate. This collaborative trial showed that the method can be considered as fit for the purpose of screening with respect to its intra- and inter-laboratory accuracy. The results demonstrated the validity of combining multiplex PCR with array detection as provided by the DualChip^® GMO (Eppendorf, Germany) for the screening of GMO. The results showed that the technology is robust, practical and suitable as a screening tool.     

Taste perception and purchase intent of oil‐in‐water spreads: effects of oil types and salt (NaCl or KCl) concentrations

Associations of sodium intake with heart‐related problems are creating awareness towards reducing sodium. Potassium chloride (KCl), a substitute for sodium chloride (NaCl), has the disadvantage of imparting bitterness at high concentrations. We evaluated physical characteristics, taste perception and purchase intent of KCl and NaCl in oil‐in‐water spreads/emulsions composed by olive, rice bran and soya bean oils. Consumers (N = 300) evaluated saltiness/bitterness of emulsions prepared with 65% oil, and NaCl (0.5% and 1.0%) or KCl (0.75% and 1.5%). Olive oil spreads (104.07–107.43 Pa s) had higher viscosity compared to other spreads (59.16–74.96 Pa s). Type of oil had significant effects on bitterness, overall taste liking and viscosity. Taste liking decreased due to bitterness of olive oil spreads (mean drop=1.72–2.43). Purchase intent was positively associated with saltiness and pH and increased with oil claims (increase = 1.3%–22.1%) compared to sodium claims (increase = 0.0%–12.9%). These findings are useful for understanding taste perception of emulsions.     

Physical characteristics of extrudates from corn flour and dehulled carioca bean flour blend

Extruded products were prepared from a corn flour and dehulled carioca bean (Phaseolus vulgaris, L.) flour blend using a single-screw extruder. A central composite rotate design was used to evaluate the effects of extrusion process variables: screw speed (318.9–392.9 rpm), feed moisture (10.9–21.0 g/100 g) and bean flour level (4.8–55.2 g/100 g) on the specific mechanical energy (SME), sectional expansion index (SEI), longitudinal expansion index (LEI), volumetric expansion index (VEI) and density (D) of the extrudates. The instrumental texture was also analyzed. The independent variables had significant effects on the physical properties (SEI, VEI and density) of extrudates, with the exception of SME and LEI. SEI increased with increasing screw speed, but a higher moisture and bean flour content resulted in decreasing SEI and VEI. The increase of moisture and bean flour increased the density of extrudates. According to texture analysis, some treatments with 30 and 45 g/100 g bean flour did not show significant differences when compared to commercial brand snacks. However, when combined with higher moisture content (≥19 g/100 g) and lower screw speed (≤333 rpm), the results of the expanded product were not satisfactory.     

Rheological properties and gel strength of Phaseolus lunatus protein/carboxymethylated flamboyant gum systems

The rheological behaviour and gel strength of hydrocolloid mixture systems (HMSs) of carboxymethylated flamboyant gum (CFG) with protein hydrolysates (PHs) of Phaseolus lunatus were examined to evaluate the influence of the protein/polysaccharide ratio (2:1 and 3:1), pH (3 and 9) and concentration of solids, according to a 2³ factorial design. The protein concentrate of P. lunatus was hydrolysed with pepsin–pancreatin enzymes. The flow curve results were fitted to the Ostwald–de Waele model. The flow behaviour index (0.66–0.78) for all conditions studied was indicative of the shear‐thinning behaviour. For the HMS, the consistency index (k) values ranged from 0.4 Pa sⁿ to 1.2 Pa sⁿ. The analyses of variance showed that the ratio of PH/CFG and pH were the main variables that had significant effect on k values (P < 0.05). Only PH system presented a weak gel‐like viscoelastic behaviour. Both functional properties were affected by the protein degree of hydrolysis (DH).     

Effect of varying oxygen concentrations on the shelf-life of fresh pork sausages packaged in modified atmosphere

A total of 105 fresh pork sausages were packaged in atmospheres varying in oxygen concentration, using the following mixtures (%O₂/%CO₂/%N₂): 0/20/80, 0/20/80 + O₂ scavenger, 20/20/60, 40/20/40, 60/20/20, and 80/20/0. In addition, two batches were subjected to vacuum packaging or over-wrap with O₂-permeable film. They were stored for 20 days at 2 ± 1 °C in the dark. Values of pH, CIE L*, a* and b* color parameters, surface metmyoglobin percentage, TBA-reactive substances, psychrotroph aerobe bacterial numbers and sensory discoloration and off-odor were assessed throughout storage. Packaging in the absence of O₂, either under vacuum or in atmosphere with O₂ scavenger, led to extension of shelf-life in terms of both color and odor stability due to low oxidation rates. Increase of O₂ caused a significant enhancement of oxidation, decrease of shelf-life due to discoloration and off-odor development. The highest O₂ concentration gave rise to a significant color improvement, though only for a limited period of 8 days.     

Determination of Phenolic Compounds in Artichoke,Garlic and Spinach by Ultra-High-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

Phenolic compounds were determined in artichoke (Cynara scolymus), garlic (Allium sativium) and spinach (Spinacia oleracea) using a single method based on simple extraction and ultra-high-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). Several compounds belonging to different families, such as phenolic acids, isoflavones, flavones and flavonols, were determined. The analytical procedure was validated in all the matrices, obtaining recoveries ranging from 60 to 120 % with reproducibility values (expressed as relative standard deviations (RSDs)) lower than 26 %. Limits of quantification (LOQs) were always equal to or lower than 50 μg/kg, except to kaempferol and its glucosides in spinach (LOQs?=?75 μg/kg). Artichoke showed higher concentration of phenolic compounds (837.2 mg/kg dry weight (DW)) than garlic (26.5 mg/kg DW) or spinach (64.5 mg/kg DW). Apigenin 7-O-glucoside (from 147.0 to 722.7 mg/kg DW) was found to be the major flavonoid in all samples of artichoke investigated, while chlorogenic acid, whose concentration ranged from 37.8 to 734.7 mg/kg DW, is the major phenolic acid in this matrix. Regarding garlic, caffeic acid (from 1.7 to 28.3 mg/kg DW) and quercetin (from 9.0 to 18.9 mg/kg DW) were the compounds detected at higher concentrations, although in general the total content was very low in relation to other matrices. In relation to spinach, ferulic acid was the major phenolic compound, and its concentration ranged from 18.0 to 41.4 mg/kg DW.     

Composition and biological effects of goldenberry byproducts: an overview

Goldenberry is a wild fruit that has been widely used for centuries, mainly in folk medicine. Most studies of goldenberry have focused on the fruit, but new research has studied its byproducts, which were considered to be waste until recently. The main objective of our study was to systematize the published information regarding the composition of goldenberry byproducts (calyces, leaves, seeds, and pomace) and their effects on biological systems. Goldenberry byproducts contain minerals, amino acids, withanolides, flavonoids, and essential fatty acids, thus representing good sources of these compounds. Some of their major biological effects include anti-inflammatory, antioxidant, antidiabetic, and antiproliferative effects. Information regarding their toxicity is also presented here. To determine the optimal dosage, further safety studies would be recommended to ensure the best health benefits of these compounds. The available evidence has demonstrated the nutritional value of different byproducts of goldenberry, suggesting them to be potential candidates for use in the cosmetic industry, in the preparation of functional foods, and in phytomedicine for the prevention and adjuvant treatment of some diseases. © 2020 Society of Chemical Industry     

Bioinformatic characterization of the extracellular lipases from Kluyveromyces marxianus

Lipases are hydrolytic enzymes that break the ester bonds of triglycerides, generating free fatty acids and glycerol. Extracellular lipase activity has been reported for the nonconventional yeast Kluyveromyces marxianus, grown in olive oil as a substrate, and the presence of at least eight putative lipases has been detected in its genome. However, to date, there is no experimental evidence on the physiological role of the putative lipases nor their structural and catalytic properties. In this study, a bioinformatic analysis of the genes of the putative lipases from K. marxianus L-2029 was performed, particularly identifying and characterizing the extracellular expected enzymes, due to their biotechnological relevance. The amino acid sequence of 10 putative lipases, obtained by in silico translation, ranged between 389 and 773 amino acids. Two of the analysed putative proteins showed a signal peptide, 25 and 33 amino acids long for KmYJR107Wp and KmLIP3p, and a molecular weight of 44.53 and 58.23 kDa, respectively. The amino acid alignment of KmLIP3p and KmYJR107Wp with the crystallized lipases from a patatin and the YlLip2 lipase from Yarrowia lipolytica, respectively, revealed the presence of the hydrolase characteristic motifs. From the 3D models of putative extracellular K. marxianus L-2029 lipases, the conserved pentapeptide of each was determined, being GTSMG for KmLIP3p and GHSLG for KmYJR107Wp; besides, the genes of these two enzymes (LIP3 and YJR107W) are apparently regulated by oleate response elements. The phylogenetic analysis of all K. marxianus lipases revealed evolutionary affinities with lipases from abH15.03, abH23.01, and abH23.02 families.