Fulgencio Marín-Iniesta

Dealcoholized wines by spinning cone column distillation: phenolic compounds and antioxidant activity measured by the 1,1-diphenyl-2-picrylhydrazyl method.

Spinning cone column (SCC) distillation has been shown to be a commercially suitable technique for dealcoholized wine (DW) manufacturing, but there are not enough studies about its influence on the DW quality. So, the effect of this technique on the antioxidant activity (% of remaining 1,1-diphenyl-2-picrylhydrazyl radical) and the phenolic compound composition of red, rose, and white DW, obtained at pilot plant scale, has been analyzed. Nineteen raw wines (RWs) from different grape varieties and five different Spanish viticultural regions have been studied before and after dealcoholization. The total phenolic content, flavonols, tartaric esters, and anthocyanins, was determined by spectrophotometry, while the content of phenolic compounds such as stilbenes (trans- and cis-resveratrol), flavonols (rutin, quercetin, and myricetin), flavan-3-ols [(+)-catechin and (-)-epicatechin], anthocyanins (malvidin 3-glucoside), and non-flavonoids (gallic, caffeic, and p-coumaric acids) was determined by high-performance liquid chromatography (HPLC). The resveratrol contents in red wines were between 1.81 and 34.01 mg/L in RWs and between 2.12 and 39.57 mg/L in DWs, Merlot being the grape producing the RWs and DWs with higher resveratrol content. In general, the percent of remaining DPPH(*) was similar or slightly higher (until 5 units of % of remaining DPPH(*)) in DWs versus RWs. This small difference may be due to removal of SO2 (that is an antioxidant) from RWs during distillation. DWs and RWs show similar contents of the studied phenolic compounds, with a tendency, in some cases, to exhibit increases after dealcoholization, caused by the concentration effect via removal of the ethanol. From this work, we can deduce that SCC distillation is a dealcoholization technique minimally destructive with the wine phenolic compounds.

Influence of oxygen supply on the stability of recombinant plasmid pTG201 in immobilized E. coli cells

SummaryCells of Escherichia coli K12, carrying the recombinant plasmid pTG201, were immobilized in ϰ-carrageenan gel in order to improve the following plasmid parameters: (i) maintenance of a high level of plasmid copy number, (ii) good plasmid stability and (iii) good expression of plasmid encoded gene. The experiments were carried out on LB medium without antibiotic selection in continuous and batch cultures supplied with air or pure oxygen. Parallel experiments with free cells were also performed. In all the cases immobilized cells presented better plasmid stability parameters than free cells. Best results were obtained with immobilized cells supplied with pure oxygen. In this case, an average plasmid copy number of 60 and a value of plasmid-carrying cells close to 100% were maintained with little change during more than 200 generations. In addition, an optical microscopy analysis is proposed to allow the quantitation of cell growth in gel beads.

Aroma Recovery in Wine Dealcoholization by SCC Distillation

The aroma recovery in wine dealcoholization by spinning cone column (SCC) distillation technique has been studied, with the analysis of the influence of the process factors: raw wine flow rate and aromatic extraction percentage. This aroma recovery has been measured in terms of aromatic richness (number of peaks obtained in the chromatogram) and aromatic intensity (total peaks area of the chromatogram) using the parameters global aromatic intensity (Iga) and aromatic concentration factor. The headspace solid-phase microextraction method and gas chromatography have been used for the determination of the aromatic compounds in raw wine and in the corresponding dealcoholized wine and the aromatic fraction separated during the SCC distillation. The optimal conditions for SCC distillation process were selected as the ones that separate the aromatic fraction with the highest Iga and the highest aromatic richness (percentage of recovered peaks) as well as with the lowest ethanol content.

Inactivation of Alicyclobacillus acidoterrestris spores by high pressure CO2 in apple cream

Alicyclobacillus acidoterrestris (A. acidoterrestris) is a bacillus-type spore former that causes significant alterations in fruit products. It is highly resistant to typical pasteurization regimes; thus, this work explored the use of high-pressure CO₂ (HPCD) for its deactivation in apple cream. The assays were conducted in a high-pressure apparatus where the cream was placed in an agitated vessel and the CO₂ passed over under different operating conditions for distinct periods of time. The HPCD was able to deactivate the A. acidoterrestris spores in the apple cream by four orders of magnitude at 30 °C and 10 MPa. On the other hand, the lethal effect of HPCD was independent of the thermal effect since the application of dry heat without CO₂ at the same temperature did not cause any A. acidoterrestris deactivation. The important variables in terms of improving the method were the flow regime and the way to put in contact the HPCD and the cream. Finally, the HPCD treatment did not affect the most important sensorial and rheological properties of the cream; although there was a slight reduction in the vitamin C content due to thermal degradation.

Processing, Packaging, and Storage of Tomato Products: Influence on the Lycopene Content

AbstractAccording to several epidemiological studies, the lycopene content of tomato and tomato-based products is related to a variety of health benefits. This has sparked interest in knowing the effect of processing and storage of tomato products on this carotenoid, in order to preserve it during manufacturing and distribution till consumption. Furthermore, in the last few years special attention has been paid to the changes of all-trans and cis-isomers of lycopene during processing and storage. In fact, cis-isomers have shown higher health-promoting properties than all-trans isomers. Heat, light, oxygen, food matrices, and ingredients such as oil are factors that have an important effect on the main lycopene degradation reactions: isomerization and oxidation. These reactions could affect the bioavailability and reduce the bioactivity of these compounds. This article reviews the lycopene changes in tomato and tomato products during preparation operations, processing, and storage using different packaging materials. Special attention has been paid to those technological conditions which may affect the lycopene stability, particularly those able to enhance the cis-forms content that have greater bioavailability than all-trans lycopene isomers.

Hygienic Design and Microbial Control of Refrigeration and Air Conditioning Systems for Food Processing and Packaging Plants

The critical control points of the refrigeration and air conditioning systems serving the food processing and packaging plants are analyzed from the hygienic viewpoint. They identified the problems of hygienic design of the various components of refrigeration systems and air conditioning installations, and several solutions are described. The lack of hygienic design of air conditioning and refrigeration systems, and their inadequate cleaning and disinfection procedures, can cause significant economic losses and epidemic diseases in people, employees, or visitors, or in the final food consumers. So, the present manuscript analyses: (1) the microbial control in refrigeration systems, including the control of Legionella, and the limitations of using biocides embedded in plastic materials (for cooling tower filling and air ducts in air conditioning systems); (2) the hygienic design of evaporative coolers (evaporative condensers and cooling towers) as a new way for controlling Legionella contamination; and (3) the microbial contamination and hygienic design of air conditioning systems for food processing and packaging rooms, including the microbial control in the air by means of UV lamps, essential oil aerosolization, and filtration. The interest of the clean rooms and microbiologically controlled environments for food processing and packaging is explained through a case study of slicing and packaging of ready-to-eat meat products.

Hydrophobic properties of cardboard coated with polylactic acid and ethylene scavengers

The corrugated cardboard used in food packaging readily absorbs moisture from the environment, especially when stored under high humidity conditions. In this research, the water barrier of cardboard was modified by changing the wettability of the cardboard surface, applying hydrophobic coatings of polylactic acid (PLA), alone or in combination with other substances that absorb gases (ethylene scavengers) such as clinoptilolite (C), sepiolite (S), and sepiolite permanganate (SP). The water barrier properties tested as water vapor permeability (WVP), water absorptiveness (WA), and water drop contact angle (CA) showed that the water resistance of the resulting cardboard was improved by the coating. The best results of these properties were obtained by using a coating of PLA 2% alone. In addition, PLA 2% with C 1.5% also showed good results, but the WA results were higher. The use of PLA coating produces a greater uniformity and smoothness of the coated cardboard surface due to the best filling of the pores or spaces between cellulose fibers. Our findings and the environmentally friendly nature of PLA strengthen the advantages of using these kinds of coatings on cardboard trays for the packaging, storage, and transport of foods such as fresh fruit and vegetables.

Mitigation of Biofilm Formation on Corrugated Cardboard Fresh Produce Packaging Surfaces Using a Novel Thiazolidinedione Derivative Integrated in Acrylic Emulsion Polymers

Various surfaces associated with the storage and packing of food are known to harbor distinct bacterial pathogens. Conspicuously absent among the plethora of studies implicating food packaging materials and machinery is the study of corrugated cardboard packaging, the worldwide medium for transporting fresh produce. In this study, we observed the microbial communities of three different store-bought fruits and vegetables, along with their analog cardboard packaging using high throughput sequencing technology. We further developed an anti-biofilm polymer meant to coat corrugated cardboard surfaces and mediate bacterial biofilm growth on said surfaces. Integration of a novel thiazolidinedione derivative into the acrylic emulsion polymers was assessed using Energy Dispersive X-ray Spectrometry (EDS) analysis and surface topography was visualized and quantified on corrugated cardboard surfaces. Biofilm growth was measured using q-PCR targeting the gene encoding 16s rRNA. Additionally, architectural structure of the biofilm was observed using SEM. The uniform integration of the thiazolidinedione derivative TZD-6 was confirmed, and it was determined via q-PCR to reduce biofilm growth by ~80% on tested surfaces. A novel and effective method for reducing microbial load and preventing contamination on food packaging is thereby proposed.