Proximate Composition and Sensory Evaluation Between Artificially Ripened and Naturally Ripened Pineapples (Ananas comosus)

The number of artificially ripened pineapples is outnumbered than the naturally ripened pineapples. However, there is a lack of understanding between artificially ripened and naturally ripened pineapples. Thus the inquiry was anticipated to explore the physicochemical changes and organoleptic acceptability of the naturally ripened and artificially ripened pineapples. Farmers used different chemicals such as calcium carbide, ethylene, besides growth hormones to reduce production loss. Here we evaluated the content of moisture, ash, protein, fat, crude fiber, reducing sugar, total sugar, titratable acidity, sucrose, and vitamin C in both naturally ripened and artificially ripened pineapples. Artificially ripened pineapples showed a significantly lower vitamin C than naturally ripened ones, but arsenic content was nil in both samples. In the case of color and appearance, there was no significant difference between the two samples, but in case of the other organoleptic properties, such as flavor, sweetness, sourness, the natural one was more acceptable. Thus naturally ripened pineapples are more beneficial to consumers than artificially ripened ones.

Characterization of the Flavor Profile of Bigeye Tuna Slices Treated by Cold Plasma Using E-Nose and GC-IMS

To avoid heat, treatment induces numerous physicochemical changes under severe conditions in the tuna, cold plasma (CP), as a non-thermal technology, possess objective potential on tuna processing. The effect of cold plasma on the volatile flavor compounds of bigeye tuna (Thunnus obesus) sashimi has been evaluated using electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS). GC–IMS results revealed a total of 33 volatile compounds in tuna slices. The effect of CP treatment on tuna flavor was not significant, furthermore CP could protect volatile freshness compounds such as 1-hexanol. Principal component analysis (PCA) of the E-nose and GC–IMS results could effectively differentiate the effect of storage to tuna sashimi. There was a high correlation between the E-nose and GC–IMS results, providing a theoretical basis for establishing the flavor fingerprint of tuna sashimi.

Evolution of Physicochemical Parameters during the Thermal-Based Production of Água-mel, a Traditional Portuguese Honey-Related Food Product

The purpose of this work was to investigate the physicochemical changes occurring during the thermal-based production of água-mel, a traditional Portuguese honey-related food product. The refractive index, color parameters (hue angle, H°; chroma, C*), and the content of total reducing sugars, glucose, fructose, total brown pigments, and 5-hydroxymethylfurfural were monitored along the entire production process, and their evolution was kinetically modelled. Thermal processing caused a gradual decrease in sugars, which was accompanied by the formation of brown pigments and 5-hydroxymethylfurfural, increased concentration of soluble solids as evaluated through refractive index measurements, as well as the appearance of darker colors. In particular, a zero-order kinetic model could explain the changes in H° and reducing sugars, while the evolution of refractive index, brown pigments, 5-hydroxymethylfurfural, C*, fructose, and glucose were best fitted using a first-order kinetics model.

Detection of efficiency of microwave-enhanced sludge treatments by dielectric measurements

Microwave irradiation is a promising pre-treatment method for sludge stabilisation, but there are few studies focusing its effect on organic matter solubility and biodegradability of wastewater and sludge originated from the food industry. In our research, microwave irradiation was applied standalone and in combination with alkaline treatment to enhance the solubilisation and biodegradation of organic matter content of meat industry wastewater and municipal sludge, respectively. The energy efficiency was investigated, as well. Dielectric measurement is a suitable method to detect physicochemical changes, therefore our research work covered the determination of dielectric properties of the investigated materials. Our experimental results have revealed that the lower power and energy intensity microwave-alkaline treatments were the most efficient pre-treatment process from energetically aspects to increase the organic matter solubility and biodegradability of wastewater and sludge. Furthermore, a strong linear correlation was found between the dielectric constant and the indicators of the solubility of organic matter (SCOD/TCOD) and aerobic biodegradability (BOD/COD) in both treated materials, respectively. Our results show that the dielectric measurements can be applied for detection of physicochemical changes, predict the improvement of biodegradability, and considered as a promising method to estimate the efficiency of sludge pre-treatment methods.

Electrodynamic approach for description of mass transfer phenomena

Based on the equations of macroscopic electrodynamics, the article considers the most important consequences from the point of view of practical application for condensed matter. It has been theoretically shown that a virtual molecular filter with a fairly high degree of selectivity can be used for them. The theoretical substantiation of mass transfer processes in condensed systems is presented for cases of external influence on them when solving problems of technological change of macroscopic properties of a molecular system. Monitoring problems are indicated when moving the minimum amount of substance in the case of mass transfer for processes: diffusion, adsorption, capillary filtration. The functioning of the filter is based on the theory of macroscopic electrodynamics, namely, on how the space charge density is distributed in the sample under study. The results obtained make it possible to evaluate the physicochemical changes that occur in a condensed medium under external technological influence. The presented theoretical research results can serve as the basis for improving the methods of electrometric monitoring of gaseous and liquid media of unknown qualitative and quantitative composition.

KMnO4 chemical kinetics in high diluted solvents

Background: A number of theoretical and experimental approaches have been signalizing towards a induction of some solvent structural order or dynamical behavior, whenever a High Dilution (HD) is prepared. These works have been performed using different spectroscopic techniques, calorimetric studies, electrical and optical measurements, among others, which results are interpreted under many different approaches. The understanding of the physicochemical nature of HDs is still far from to be clarified, despite the evidences on their biological activity. Assuming that physicochemical changes induced by shaking and dilution (potentization) are true, one could expect that the changed solvent could interfere in the chemical kinetics of a complex reaction. The reduction of Mn7+ to Mn2+ (color change) observed when KMnO4 in transferred into an acidic solvent is a self-catalyzed reaction dependent on pH, temperature and concentration with many reaction pathways, but converging usually to the colorless Mn2+ state (the Mn2+ produced in the Mn7+ reduction is the reaction catalyzer). Method: We have performed this reaction using oxalic and sulphuric acid as solvent, observing the time dependence of the absorbance at λ = 525 nm. Some solvent variants were proofed: G0: normal solvent; G1: potentized solvent at 12x; G2: Mn2+ potentized in normal solvent until 12x. If the potentization itself could change the solvent, we would expect differences in G1 compared to G0. If some Mn2+ information were imprinted into the solvent due the potentization we would expect differences in G2 to G1 and G0. It was recorded 10 spectra for each solvent variant and the experiment was performed twice (different weeks), with different fresh starting solutions (KMnO4, acid solvent and variants). Averaged values and standart deviations were compared. Results: The only difference observed were a randomic time delay (few seconds) to start the decrease in the absorbance at λ = 525 nm. This delay was associated to the natural diffusion of KMnO4 in the solvent and the time left to insert the cuvette into the spectrometer as well to turn the measurements on. After delay correction, all curves showed similar behavior (unsignificant differences), that its typical decrease. Conclusion: If potentization is able to induce changes in the solvent, these were not able to affect the chemical kinetics of the KMnO4 in acidic medium. One could hypothetize this model is not responsive to those putative changes either by the unspecificity of a chemical solution (no similitude is achieved) or by the lack of a biological sensor able to interpret such changes. Another conclusion would be that no changes are induced on the solvent due potentization.

Combined Use of Vinasse and Nitrogen as Fertilizers Affects Nitrification, Ammonification, and Denitrification by Prokaryotes

A common agricultural practice of combining organic fertilizer vinasse (a liquid residue from sugarcane ethanol production) with mineral nitrogen (N) fertilizer promotes N losses such as greenhouse gas emissions due to the effects of physicochemical changes in soil on the microbiota inhabiting this environment. In this study, we applied microarray GeoChip v.5.0M technology to obtain a better insight into the prokaryotic communities and identify and quantify the N functional gene families associated with the N processes in sugarcane soils without N fertilizer (N0), with urea at 60 kg ha−1 (N60), and with vinasse combined with urea (NV). Soil samples were collected at 7 (T7) and 150 (T150) days after N application, corresponding to maximum and minimum nitrous oxide (N2O) emissions, respectively, for molecular and physicochemical analysis. Additionally, the metagenomes of these DNA samples, previously deposited in the MG-RAST server, were accessed to investigate the functions and taxonomic groups associated with selected gene families. The results revealed that 87% of the select gene families were significantly responsive to the fertilizer combined treatment (NV) in the 7 days after the application. The most responsive genes and processes were nitrification [with the amoA gene from ammonia-oxidizing Bacteria (AOB) and Archaea (AOA) and hao from Bacteria], ammonification (with gdh and ureC genes from Bacteria and Archaea), and denitrification (with p450nor from Eukarya). The AOA, Nitrosopumilus, and AOB, Nitrosomonas, were the groups with the greatest functions associated with nitrification, as well as a pathogenic Mycobacterium, with denitrification. The results also revealed that under N fertilizers and decreased O2 in soil, the increases in K and P nutrients can promote the growth of the halophile Archaea Natronomonas and the Bacteria Anaeromyxobacter, which can reduce N2O. In conclusion, this typical agricultural fertilization management may favor functional genes and archaeal and bacterial groups associated with N processes that have the potential to reduce environmental damage in tropical sugarcane soils.