Changes in the volatile composition of Spanish-style green table olives induced by pasteurisation treatment

Thermal treatment of pasteurisation is the most widely used stabilisation method for packed green table olives. In the present work, the influence of pasteurisation on the composition of volatile compounds in packed Spanish-style green table olives was studied. To this aim, two thermal processes (P1 = 85 °C for 7 min; P2 = 85 °C for 15 min) were evaluated by comparing the contents of volatile compounds in pasteurised olives with those in unpasteurised olives. Volatiles were analysed, both in olive juice and cover brine, by means of headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). Both pasteurisation treatments caused significant increases in diverse ethyl and methyl esters and in volatile compounds derived from several chemical reactions (lipid oxidation, Maillard reaction, degradation of carotenoids). Significant differences between samples subjected to P1 and P2 were only found for 1-octen-3-ol, pentanal and 6-methyl-5-hepten-2-one in olive juice.     

Machine learning techniques to predict different levels of hospital care of CoVid-19

Applied Intelligence - In this study, we analyze the capability of several state of the art machine learning methods to predict whether patients diagnosed with CoVid-19 (CoronaVirus disease 2019)...     

Farmed meagre,Argyrosomus regius of three different sizes: what are the differences in flesh quality and muscle cellularity?

Larger meagre are more common in the market but, recently, smaller fish have started to be commercialised as well. This study aims to evaluate flesh quality and muscle cellularity of meagre of three different sizes: 800, 1500 and 2500 g. Results showed a higher fat content in larger fish (2.9% compared to 1.3% in small fish), and that texture was not affected by fish size. In terms of muscle cellularity, a higher frequency of smaller fibres was observed in 800 and 1500 g (33% compared to 18% in 2500 g) meagre, whereas in 2500 g meagre, there was a higher frequency of larger fibres. Muscle fibre density was reduced with fish weight (431 and 297 fibres mm^?2 for 800 and 2500 g meagre, respectively). In conclusion, this study shows that meagre of different weights are different in terms of fat content and muscle cellularity and that 800 g meagre seems to have a good potential for being commercialised.     

Chemometric characterisation of the fats released during the conditioning processes of table olives

This work deals with the characterisation of five fat types released during the conditioning process of table olives, pitting green olives (PGF), pitting ripe olives (PRF), pitting/stuffing green olives with vegetable origin products (PSGVF) and pitting/stuffing green olives with animal origin materials (PSGAF) along with the fat collected at the end of the factory sewer (WF). The parameters analysed included: acidity, peroxide value, spectrophotometric measurements (K₂₃₂, K₂₇₀ and ΔK), fatty acid composition of the raw material and the neutral fat, triacylglycerol composition of the neutral fat as well as the proportion and composition of the polar fraction. A chemometric analysis of specific groups of compounds was able to establish differences among the types of fats; the overall analysis showed two major groups: PGF, PRF and PSGVF were only moderately degraded, and PSGAF and WF were highly degraded. The information provided can help industries and authorities to handle these residues properly.     

Barrier and optical properties of edible hydroxypropyl methylcellulose coatings containing surfactants applied to fresh cut carrot slices

Coatings made from hydroxypropyl methylcellulose (HPMC) containing surfactant mixtures of sorbitan monostearate (SPAN 60) and sucrose palmitate (sucrose ester P-1570) in aqueous and hydroalcoholic media were developed to analyse the effect of the hydrocolloid/surfactant ratio (H/S), the hydrophilic–lipophilic balance (HLB) of the surfactant mixtures and the solvent type used as dispersing media on the water vapour barrier properties of the films and their optical effect when applied to carrot slices. The results showed that the solvent type, H/S ratio and HLB significantly affected viscosity, surface tension, and stability (particle size and flocculation rate) of the film-forming dispersions, which in turn had a great influence on the extensibility and final film structure of the coating on the carrot surface. All these aspects affected the water vapour barrier properties of the film. The best water vapour barrier properties were found in the coating made from hydroalcoholic dispersions with intermediate values of the surfactant's HLB. The colour of coated carrot slices was mainly affected by the solvent dispersion media, the induced changes being greater for aqueous dispersions.     

A Bacillus thuringiensis strain producing epizootics on Plodia interpunctella: A case study

After several disease outbreaks in laboratory cultures of pyralid moths in Tabriz University, Iran, during 2004 and 2005, a new Bacillus thuringiensis aizawai strain EF495116 (BTA) was isolated from a dead Plodia interpunctella larva. A complete characterization of the strain was performed, including serological identification, protein and plasmid pattern determination, a PCR-based identification of virulence-related genes, nucleotide sequence analysis of the 16S rDNA and gyrB genes (in order to find out relationships between the species with other virulent Bacillus pathogens), and biological activity assays. These studies revealed that BTA produced a major parasporal protein band of about 135 kDa, bore seven out of the fourteen pyralid-active genes analyzed (cry1Aa, cry1Ab, cry1C, cry1D, cry1I, cry2A and cry9) and was toxic against P. interpunctella and P. xylostella larvae, with LC₅₀ values of 7.13 and 3.1 μg/mL, respectively. Although these features are common among other B. thuringiensis strains active on Lepidoptera, their role in epizootics is uncertain. However, sequence analysis of the 16S rDNA and gyrB genes revealed that BTA clustered with one of the few B. thuringiensis strains identified as a medical isolate. Interestingly, both strains, like many others reported to produce epizootics, belong to serovar aizawai. The implication of serovar or serovar-dependent genes in epizootics is discussed.     

Time-Dependent Cytotoxic Properties of Terpyridine-Based Copper Complexes

Five copper complexes supported by terpyridine ligands were prepared and characterized, viz. [Cu₃Cl₄(naphtpy)₂][CuCl₂] ( 1 ), [Cu₂Cl₂(naphtpy)₂](ClO₄)₂ ( 2 ), [CuCl₂(naphtpy)]₂(MeOH)₃(H₂O) ( 3 ), [CuCl₂(Cltpy)] ( 4 ) and [Cu(Cltpy)₂](ClO₄)₂ ( 5 ); (where naphtpy stands for 4’-((naphthalen-2-yl)methoxy)-2,2′:6′,2′′-terpyridine and Cltpy for 4′-chloro-2,2′:6′,2′′-terpyridine). Their ability to interact with DNA was investigated, and their cytotoxic behaviour was examined with three cells lines, namely human ovarian carcinoma cells (A2780), their derived cisplatin-resistant line (A2780cis), and human cervix adenocarcinoma cells (HeLa). All compounds show good cytotoxic properties (especially after 72 h of incubation). Remarkably, two compounds, 4 and 5 , are still almost inactive after 24 h (particularly 4 ), but are highly active after 72 h, with IC₅₀ values in the low-micromolar to sub-micromolar range. Compounds 1 and 2 induce necrosis, whereas late apoptosis is observed with 3 – 5 , 4 exhibiting a behaviour close to that of cisplatin.     

Polyphenoloxidase (PPO) activity and osmotic dehydration in Granny Smith apple

Osmotic dehydration (OD) permits the preservation of foods via a decrease in water content and an increase in solute concentration. Osmotically dehydrated fruits such as apple are suitable for the manufacture of desserts, cakes, salads, yoghurts, etc. Different microstructural and engineering aspects of OD are already known, but its effects on enzymatic activity are still unknown. This study analyses the activity of polyphenoloxidase (PPO) in fresh Granny Smith apples and the effect that OD by immersion in sucrose‐saturated syrup has on this activity. The low PPO activity found in the edible parenchyma of osmotically dehydrated apples is attributed to penetration by the osmotic agent and flooding of the intercellular spaces, which produces a low moisture content and a limited O₂ concentration in the immediate environment of the enzyme. These results show that OD prevents enzyme–substrate interaction. Thus the low PPO activity would reduce browning of this type of product. Copyright © 2005 Society of Chemical Industry