Effect of ozone treatment on the microstructure, chemical composition and sensory quality of apple fruits

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research commissioned by Agricultural services co-operative society ‘AUGL¸ NAMS’ has been conducted within framework ‘The research of fruit storage technologies’ funded by State program ‘Competence Centre for Food in Latvia’.The aim of this study was to assess the effect of O3 treatment on the quality of different cultivars of apples (Malus domestica Borkh.). Apples were stored for six months at different concentrations of ozone. During the research, minor differences between ozone-treated and control fruits were found in terms of cell integrity and epicuticular wax structure. Ozone application for apple treatment could accelerate the natural ageing of the waxes found on the surface of apples, thereby reducing the thickness of the waxes. The rate of degradation for the epicuticular wax was found to be cultivar dependent. After six months of storage, the ozonation process prevented the decay of ‘Iedzenu’, ‘Auksis’ and ‘Belorusskoje Malinovoje’ apple cultivars, but it accelerated damage in the ‘Gita’ apple cultivar. A positive impact of ozone during long-term storage was found regarding flesh firmness of ‘Iedzenu’ apple cultivar samples subjected to O3 exposure at concentrations of 0.8 ppm and 3.0 ppm. In other cultivars of apples, significant differences between ozonation and cold storage (control) were not found. In general, ozone treatment has a potential to be applied in order to maintain the sensory quality and biologically active compound level in apples during six-month storage; however, the degree of effectiveness depends both on the cultivar and on the concentration of ozone.Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

FOODBALT 2014 APPLICATION OF ENZYMATIC TREATMENT TO IMPROVE THE CONCENTRATION OF BIOACTIVE COMPOUNDS AND ANTIOXIDANT POTENTIAL OF WHEAT AND RYE BRAN

Abstract The present study was undertaken to establish the effect of enzymatic treatment on the content of total phenolic compounds and antioxidant activity in enzymatically treated bran. Enzymatic hydrolysis of bran was carried out by α-amylase from Bacillus amyloliquefaciens (Sigma Aldrich) for breakdown the bonds between glucose monomers in starch. Multi enzyme complex (Viscozyme L) containing a wide range of carbohydrases were used for depolymerisation of cellulose and hemicelluloses molecules. The 80% ethanol was used to extract the antioxidant compounds from bran. Free radical scavenging activity of samples was measured using 2.2-diphenyl-1-picrylhydrazyl (DPPH). Assay and the data were expressed in Trolox equivalents (TE) per 100 g -1 of sample, as well the reducing power was determined using ferric reducing antioxidant power (FRAP) assay and the data were expressed in the same indices. The obtained results showed that the enzymatically treated bran samples had the highest concentration of total phenolic compounds, on the other hand the enzymatically treated bran showed higher antioxidant potential than nonenzymatically treated bran samples. Extract from enzymatically treated rye bran had the highest concentration of phenolic compounds, 1230±42.57 mg GAE 100 g -1 DW. The lowest concentration of phenolic compounds was found in untreated wheat bran samples and this amount was equal to 377±9.78 mg GAE 100 g -1 DW. Two different methods of evaluation of the bran antioxidant activity showed potential usefulness of enzymatic treatment

Influence of 1-Methylcyclopropene and ULO Conditions on Sensory Characteristics of Apple Fruit Grown in Latvia

The aim of the study was to evaluate the influence of 1-methylcyclopropene (1-MCP) treatment and ultra-low oxygen (ULO) storage conditions on the sensory characteristics of apples. Two apple storage technologies were tested in this study: cold storage under traditional conditions in combination with 1-MCP treatment, and ULO storage with two different compositions of a gas mixture. Apples were stored for 6 months. After storage, the sensory characteristics were analysed. Sensory evaluation showed that storage technology affected the sensory characteristics and panelists’ acceptability. Distinctive differences were found between apples stored under controlled atmosphere and traditional conditions. Trained panelists highlighted that samples stored under controlled atmosphere had pronounced juiciness and color, while 1-MCP-treated apples stored in cold were sweeter and more aromatic. Apples of the autumn cultivar ‘Auksis’, was perceived considerably higher after harvest and before long-term storage, compared with other cultivars. During 6 months of storage in controlled atmosphere, the sensory quality of these apples remained intact. Also, the sensory quality of fruit of the winter cultivar ‘Sinap Orlovskij’ throughout 6 months of its storage in controlled atmosphere remained intact. Besides, it was noticed that apples stored in controlled atmosphere were juicier and more aromatic with intense color. There is a positive effect of 1-MCP treatment on maintenance of apple quality stored in normal atmosphere for 6 months. With regard to some quality parameters and sensory attributes, 1-MCP-treated apples stored under normal atmosphere are comparable to those stored under ULO conditions

Assessment of Shelf-Life Ability of Apples cv. ‘Auksis’ after Long-term Storage Under Different Conditions

The objective of the current research was to ascertain the shelf-life ability of apple ‘Auksis’ after 6 months of cold storage under different conditions. The effect of storage conditions such as: cold storage under normal atmosphere (NA), 1-methylcyclopropene (1-MCP) + cold storage, and ultra-low oxygen (ULO)-controlled atmosphere (CA) [2.0% CO2 and 1.0% O2 (ULO1) and 2.5% CO2 and 1.5% O2 (ULO2)] on the quality of apples during shelf-life was evaluated. Apple fruits immediately after cold storage and after 25 days of maintaining at market condition had been evaluated. The physical (firmness, weight losses), chemical (total soluble solids and acid contents), and sensory (aroma, taste, acidity, sweetness, juiciness, and color) characteristics of apples had been evaluated after 5, 10, 15, 20, and 25 days to ascertain maximal shelf-life. Results from sensory evaluation indicated that apples treated with 1-MCP and stored at NA were characterized with distinctive aroma, whereas apples stored under CA were poor in sweetness and had remarkable acidity and juiciness. Apples that were stored in cold had pronounced aroma and color but without taste. Based on the evaluation by panelist, maximum shelf-life of apples that were kept under cold storage and ULO1 was 15 days, whereas that of apples that had been treated with 1-MCP and stored at NA and those stored in ULO2 was 25 days

Effect of Essential Oils Supplemented with Caprylic Acid and Sodium Chloride against Faecal ESBL-Producing Escherichia coli Isolated from Pigs

The purpose of the present investigation was to compare the antibacterial activity of six commercial and lab-scale extracted essential oils (EOs) alone or in combination with caprylic acid (CA) and sodium chloride (NaCl) against faecal Escherichia coli with and without extended-spectrum beta-lactamase (ESBL) encoding genes, and of isolates classified as multidrug-resistant (MDR). Gas chromatography–mass spectrometry (GC–MS) was used for the analysis of chemical composition of EOs, while the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were carried out to elucidate the antibacterial activity of non-supplemented and supplemented EOs against different resistance levels of E. coli strains. The main compounds in commercial EOs were aromatic monoterpenoids (30–56%) and p-cymene (8–35%), while the main compounds in the lab-scale EOs were aromatic monoterpenoids (12–37%) and γ-terpinene (18–22%). Commercial EOs exhibited superior inhibitory activity of E. coli in comparison to lab-scale produced EOs. Antibacterial activity of EOs was significantly enhanced by enrichment of the EOs with NaCl (p < 0.001) or CA (p = 0.012). Most of the non-supplemented EOs exhibited lower activity against MDR and ESBL producing E. coli. In contrast, EOs supplemented with CA and especially NaCl was equally effective against ESBL and non-ESBL as well as MDR and non-MDR E. coli. It was found that supplementation of EOs with NaCl could enhance the antibacterial activity towards ESBL and MDR E. coli isolates. However, additional studies are needed to clarify the potential risks of developing resistance

Effect of Essential Oils Supplemented with Caprylic Acid and Sodium Chloride against Faecal ESBL-Producing <i>Escherichia coli</i> Isolated from Pigs

The purpose of the present investigation was to compare the antibacterial activity of six commercial and lab-scale extracted essential oils (EOs) alone or in combination with caprylic acid (CA) and sodium chloride (NaCl) against faecal Escherichia coli with and without extended-spectrum beta-lactamase (ESBL) encoding genes, and of isolates classified as multidrug-resistant (MDR). Gas chromatography–mass spectrometry (GC–MS) was used for the analysis of chemical composition of EOs, while the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays were carried out to elucidate the antibacterial activity of non-supplemented and supplemented EOs against different resistance levels of E. coli strains. The main compounds in commercial EOs were aromatic monoterpenoids (30–56%) and p-cymene (8–35%), while the main compounds in the lab-scale EOs were aromatic monoterpenoids (12–37%) and γ-terpinene (18–22%). Commercial EOs exhibited superior inhibitory activity of E. coli in comparison to lab-scale produced EOs. Antibacterial activity of EOs was significantly enhanced by enrichment of the EOs with NaCl (p p = 0.012). Most of the non-supplemented EOs exhibited lower activity against MDR and ESBL producing E. coli. In contrast, EOs supplemented with CA and especially NaCl was equally effective against ESBL and non-ESBL as well as MDR and non-MDR E. coli. It was found that supplementation of EOs with NaCl could enhance the antibacterial activity towards ESBL and MDR E. coli isolates. However, additional studies are needed to clarify the potential risks of developing resistance

An Environmentally Friendly Approach for the Release of Essential Fatty Acids from Cereal By-Products Using Cellulose-Degrading Enzymes

The main intention of the present work was to investigate the ability of cellulose-degrading enzymes (C-DE) to release fatty acids (FAs) from complex matrices of cereal by-products during enzymatic hydrolysis (EH). For this purpose, three types of cereal bran (CB), i.e., wheat, rye, and oat, were used as lignocellulose substrates for three commercially available hydrolytic enzymes, i.e., Viscozyme L, Viscoferm, and Celluclast 1.5 L. The yield and composition of FAs after EH were assessed and compared with those obtained after either conventional Soxhlet extraction or after alkaline-assisted hydrolysis (A-AH) with 10% KOH in 80% MeOH and subsequent liquid&ndash;liquid extraction. The experimental results demonstrated that up to 6.3% and 43.7% higher total FA yield can be achieved by EH of rye bran using Celluclast 1.5 L than by A-AH and Soxhlet extraction, respectively. However, the application of Viscoferm for EH of wheat bran ensured up to 7.7% and 13.4% higher total FA yield than A-AH and Soxhlet extraction, respectively. The concentration of essential linolenic acid (C18:3) in lipids extracted after EH of rye bran with Celluclast 1.5 L was up to 24.4% and 57.0% higher than in lipids recovered by A-AH and Soxhlet extraction, respectively. In turn, the highest content of linolenic acid in wheat bran lipids was observed after EH with Viscoferm and Viscozyme L, ensuring 17.0% and 13.6% higher yield than after A-AH, respectively. SEM analysis confirmed substantial degradation of the CB matrix promoted by the ability of C-DE to act specifically on glycosidic bonds in cellulose and on xylosidic bonds in arabinoxylans, arabinans, and other arabinose-containing hemicelluloses. Structural alterations in cell integrity greatly contributed to the release of bound FAs and their better transfer into the extraction solvent. It has been shown that the proposed process of EH can be used for the efficient release of FAs from the CB matrix more sustainably and with a safer profile, thereby conveying greener production of FAs for certain purposes

Analysis of 18 Free Amino Acids in Honeybee and Bumblebee Honey from Eastern and Northern Europe and Central Asia Using HPLC-ESI-TQ-MS/MS Approach Bypassing Derivatization Step

The profile of amino acids and mono- and disaccharides in conventional polyfloral honey originated from Latvia and Tajikistan and less found in nature bumblebee honey from Russia was investigated. The analysis of free amino acids (FAAs) accomplished by multiple reaction monitoring (MRM) using triple quadrupole mass selective detection (HPLC-ESI-TQ-MS/MS) revealed the presence of 17 FAAs. The concentration of FAAs varied in the range of 0.02&ndash;44.41 mg 100 g&minus;1 FW. Proline was the main representative of FAAs, contributing to the total amount of FAAs from 41.7% to 80.52%. The highest concentration of proline was found in bumblebee and buckwheat honey, corresponding to 44.41 and 41.02 mg 100 g&minus;1, respectively. The concentration of essential amino acids (AAs), i.e., leucine, and isoleucine was found to be the highest in buckwheat honey contributing up to 12.5% to the total amount of FAAs. While, the concentration of branched-chain AAs fluctuated within the range of 1.08&ndash;31.13 mg 100 g&minus;1 FW, with buckwheat honey having the highest content and polyfloral honey the lowest, respectively. The results of this study confirmed the abundance of FAAs both in honeybee and bumblebee honey. However, the concentration of individual FAAs, such as proline, aspartic acid, leucine, and isoleucine in bumblebee honey was many folds higher than observed in honeybee polyfloral honey

The Impact of Eggshell Thickness on the Qualitative Characteristics of Stored Eggs Produced by Three Breeds of Laying Hens of the Cage and Cage-Free Housed Systems

The study aimed to compare the physical-chemical attributes of table eggs from three laying hen breeds housed in the cage and cage-free conditions and to characterize the morphological characteristics of the eggshell interior. A morphological and elemental analysis performed by scanning electron microscope coupled with energy dispersive X-ray spectroscopy revealed no abnormalities in the structural integrity of eggshells. The thickness of the eggshell varied in the range from 356.2 to 366.4 µm, with no statistically significant differences between the values. Eggshell membrane thickness was between 20.0 and 59.9 µm, with eggs derived from cage-housed hens, i.e., H/LS/CCE and H/HN/CCE having thinner membrane layers. The results revealed no direct relationships between eggshell and membrane thickness and physical-chemical parameters’ change. However, the presence of thick and long spider-like microcracks on the eggshell surface of eggs from cage-free housed hens H/D/BWE was the main factor that presumably contributed to substantial weight loss during 36 days of egg storage. A noticeable decline in eggshell-breaking strength along with the enlargement of air cells was observed in eggs produced under an enriched cage system H/LS/CCE after 28 days. In contrast, the minor changes in air cell size occurred in eggs from cage-free housed laying hens H/D/BWE. Protein quality indicators such as albumen height and Haugh units were well correlated with each other, and the intensity of their changes during egg storage, to a greater extent, was found to be storage time-dependent. No significant depletion of egg albumen was revealed during the first 15 days of egg storage. According to the United States Department of Agriculture, the quality corresponded to grade A (reasonably firm). However, after 18 days of storage, Haugh unit values were lower than 60, corresponding to grade B (weak and watery). The most apparent reduction in the Haugh unit was observed in eggs produced by enriched cage H/HN/CCE and cage-free H/D/BWE hens. The egg quality was storage time-dependent, and their deterioration rate was primarily associated with the genetic background of laying hens and housing conditions