Use of Electromagnetic Radiation (EMR) in Preservation of Fruit Juices

This study shows the bactericidal effect of Electromagnetic Field on fruit juice microbes. Short shelf-life period of fruit juice caused by spoilage organisms has limiting factor for its economy value. The Eighteen microorganisms isolated from both fresh and spoilt fruit samples (Pineapple and Apple), and identified during the study include, twelve (12) bacteria and Six (6) fungi, out of which only the bacterial isolates were exposed to electromagnetic field of 0mG, 500mG, and 5000mG for thirty minutes. The bacteria species were Leuconostoc mesentroides, Bacillus species, Lactobacillus brevis, Microbacterium species, Clostridium species, Bacillus cereus, Acetobacter aceti, and Staphylococcus aureus. The Gram negative bacteria isolates were Erwinia carotovora, Erwinia ananas, and Proteus species. Exposure of the isolates to an electromagnetic field of 0mG, 500mG and 5000mG showed a decrease in some electromagnetic field magnitude. This study shows reduction in growth range among most bacterial species tested at 500mG electromagnetic radiation exposure, but the growth of many of these bacterial species were triggered at 5000mG electromagnetic radiation exposure. This may mean an initiation of: adaptation mechanism, growth mechanism in some microorganism, and sugar content of the fruit juice from which they are being isolated. The exposure of the bacteria to electromagnetic field elicited detectable responses therefore depends on the adaptation mechanism of each bacteria and sugar content of the fruit from which it is being isolated from. Thus, future research can be done to optimize the limits specified for target microbes that are strength and frequency of this EMF in diseases control.

Toxicity evaluation of collagen hydrolysates from chrome shavings and their potential use in the preparation of amino acid fertilizer for crop growth

Resource utilization of chrome shavings (CS) has attracted a lot of attention from scientists and technologists in leather industry. Especially, the collagen hydrolysates extracted from CS are expected to find potential application values in agricultural field. However, there is no biotoxicity analysis of collagen hydrolysates from CS. Herein, the collagen hydrolysates with different molecular weights were produced from CS by three hydrolysis dechroming methods including alkaline hydrolysis, enzymatic hydrolysis and alkaline-enzymatic synergistic hydrolysis, and the optimal hydrolysis process of CS was designed and conducted. To evaluate their toxicity, the three collagen hydrolysates were formulated into a nutrient solution for zebrafish development. The obtained results indicated that the hydrolysates with low concentrations (less than 0.6 mg/mL) were safe and could promote the development for zebrafish embryos. Furthermore, the three collagen hydrolysates were utilized as organic nitrogen sources and formulated into amino acid water-soluble fertilizers (AAWSF) including alkaline type fertilizer (OH), enzymatic type fertilizer (M) and alkaline-enzymatic type fertilizer (OH–M) for the early soilless seeding cultivation of wheat, soybean and rapeseed. It is worth mentioning that the chromium contents in the prepared AAWSF were less than 10 mg/kg, which is far less than the limit value in the standard (China, 50 mg/kg). The growth and development of seedlings (germination rate, plant height, fresh weight of leaves, soluble sugar content and chlorophyll content) were investigated. The corresponding results showed that the growth of seedlings watered with AAWSF was better compared with the other treatments, and the OH–M fertilizer had the best promoting effect on the seedlings growth and development, followed by the M and OH fertilizers. The safe toxicity assessment of the collagen hydrolysates will expand their application scope, and the use of collagen hydrolysates extracted from CS for seedlings growth also provides an effective and reasonable way to deal with the chromium-containing leather solid waste, which is an effective way to realize its resource utilization. Graphical Abstract

Optimization of Solvent-Free Microwave-Assisted Hydrodiffusion and Gravity Extraction of Morus nigra L. Fruits Maximizing Polyphenols, Sugar Content, and Biological Activities Using Central Composite Design

Black mulberry, Morus nigra L. (family: Moraceae), is a healthy food and medicinal plant. Microwave hydrodiffusion and gravity (MHG) is one of the most innovative applications of solvent-free microwave extraction. The aim of this study was to optimize for the first time the MHG solvent-free extraction of polyphenols and sugars from M. nigra fruits. Optimization was carried out using a central composite design (CCD) with selected responses such as extraction yield, total polyphenol (TPC), flavonoid (TFC), anthocyanin (TAC), and sugar (TSC) contents, in addition to DPPH radical scavenging, and α-glucosidase (AGHi), lipase (Li), and xanthine oxidase (XOi) inhibition as tools to evaluate the best parameters for efficient and rapid extraction of black mulberry. The optimized extract was characterized in terms of the aforementioned parameters to validate the models, and was further analyzed for 36 individual polyphenols using HPLC-MS/MS. The optimized MHG extract was finally compared with traditional extracts, and demonstrated much better performance in terms of TPC, TAC, and Li, while the traditional extracts showed better XOi and AGHi. In conclusion, MHG is a valuable green technique for the production of non-degraded black mulberry polyphenol-rich extract and we suggest its larger use in the pharmaceutical and food industries.

Sugar Metabolism and Transcriptome Analysis Reveal Key Sugar Transporters during Camellia oleifera Fruit Development

Camellia oleifera is a widely planted woody oil crop with economic significance because it does not occupy cultivated land. The sugar-derived acetyl-CoA is the basic building block in fatty acid synthesis and oil synthesis in C. oleifera fruit; however, sugar metabolism in this species is uncharacterized. Herein, the changes in sugar content and metabolic enzyme activity and the transcriptomic changes during C. oleifera fruit development were determined in four developmental stages (CR6: young fruit formation; CR7: expansion; CR9: oil transformation; CR10: ripening). CR7 was the key period of sugar metabolism since it had the highest amount of soluble sugar, sucrose, and glucose with a high expression of genes related to sugar transport (four sucrose transporters (SUTs) or and one SWEET-like gene, also known as a sugar, will eventually be exported transporters) and metabolism. The significant positive correlation between their expression and sucrose content suggests that they may be the key genes responsible for sucrose transport and content maintenance. Significantly differentially expressed genes enriched in the starch and sucrose metabolism pathway were observed in the CR6 versus CR10 stages according to KEGG annotation. The 26 enriched candidate genes related to sucrose metabolism provide a molecular basis for further sugar metabolism studies in C. oleifera fruit.

Evaluation of physicochemical, sensory, and antimicrobial properties of small-scale produced fruit vinegars

Hungarian fruit vinegars were characterised in terms of physicochemical attributes (total polyphenol content, antioxidant characteristics/FRAP, CUPRAC, ABTS/, ascorbic acid content, pH, total soluble solids), sensory profiles, and antimicrobial properties. Both compositional and sensory profiles showed distinct patterns depending on the type of vinegar (Tokaj wine, balsamic or apple) and the additional fruit used. Balsamic vinegars maturated on rosehip, sea buckthorn, and raspberry showed outstanding antioxidant performances. Rosehip, raspberry, and quince vinegars, as well as vinegars produced from Tokaji aszú and balsamic apple obtained high scores for fruity and sweet notes. Antimicrobial activities were tested on Gram-negative and Gram-positive organisms, including probiotic bacteria. Generally, only weak activities were obtained, which was attributed to the natural sugar content of the samples, depending on the type of the vinegar and the fruit. Similar results, but more pronounced bacterial growth inhibitions were obtained for probiotic strains, however, some probiotic strains were resistant to at least two of the vinegars. Based on these, balsamic apple, raspberry, rosehip, quince, and sea buckthorn may qualify as potential functional components of probiotic preparations containing some of the strains tested.

Increase in Fermentable Sugars of Olive Tree Pruning Biomass for Bioethanol Production: Application of an Experimental Design for Optimization of Alkaline Pretreatment

Olive Tree Pruning (OTP) biomass can be considered a suitable source of fermentable sugars for the production of second-generation bioethanol. The present study proposes a remarkable alternative for the valorization of olive tree pruning residues. OTP biomass was processed using a sequential calcium hydroxide pretreatment/enzymatic hydrolysis. A 24–1 half fractional factorial design was adopted for the screening of process variables and a central composite design was used for the optimization stage. Temperature and lime loading resulted statistically significant. The following optimal conditions were obtained: 0.01 g of Ca(OH)2/g of dry material, 20 g of H2O/g of dry material at 160 °C for 2 h. The mathematical model that governs this alkaline pretreatment was obtained with a 76% adjusted determination coefficient, which means that it is a good representation of the process. Under optimal operating conditions, 13% of the cellulose and 88% of the hemicellulose was solubilized. Moreover, the fermentable sugar content increased 1800% compared with the initial conditions, obtaining 240 g of glucose per kg of OTP residue. The fermentable sugars obtained after the calcium hydroxide pretreatment and enzymatic hydrolysis of OTP biomass yielded 2.8 g of ethanol/100 g of raw material.

Apple Fruit Growth and Quality Depend on the Position in Tree Canopy

Modern apple orchard systems should guarantee homogeneity of fruit internal and external qualities and fruit maturity parameters. However, when orchards reach productive age, a variation of these parameters takes place and mostly it is related to uneven light distribution within the tree canopy. The aim of the study was to evaluate the canopy position’s effect on fruit internal and external quality parameters. This is the first study where all the main fruit quality and maturation parameters were evaluated on the same trees and were related to the light conditions and photosynthetic parameters. Four fruit positions were tested: top of the apple tree, lower inside part of the canopy, and east and west sides of the apple tree. Fruit quality variability was significant for fruit size, blush, colour indices, total sugar content, dry matter concentration, accumulation of secondary metabolites and radical scavenging activity. Fruit position in the canopy did not affect flesh firmness and fruit maturity parameters such as the starch index, Streif index and respiration rate. At the Lithuanian geographical location (55°60’ N), significantly, the highest fruit quality was achieved at the top of the apple tree. The tendency was established that apple fruits from the west side of the canopy have better fruit quality than from the east side and it could be related to better light conditions at the west side of the tree. Inside the canopy, fruits were distinguished only by the higher accumulation of triterpenic compounds and higher content of malic acid. Light is a main factor of fruit quality variation, thus all orchard management practices, including narrow two-dimensional tree canopies and reflecting ground covers which improve light penetration through the tree canopy, should be applied.

Xylella fastidiosa and Drought Stress in Olive Trees: A Complex Relationship Mediated by Soluble Sugars

Xylella fastidiosa (Xf) subsp. pauca “De Donno” is the etiological agent of “Olive Quick Decline Syndrome” (OQDS) on olive trees (Olea europaea L.); the presence of the bacterium causes xylem vessel occlusions inducing a drought stress and the development of leaf scorch symptoms, which may be worsened by water shortage in summer. In order to evaluate how the two stress factors overlap each other, the carbohydrate content and the expression patterns of genes related to carbohydrate metabolism have been evaluated in two olive cvs trees (Cellina di Nardò, susceptible to Xf, and Leccino, resistant to Xf) reporting transcriptional dynamics elicited by Xf infection, drought, or combined stress (drought/Xf). In the Xf-susceptible Cellina di Nardò plants, Xf and its combination with drought significantly decrease total sugars compared to control (−27.0% and −25.7%, respectively). In contrast, the Xf-resistant Leccino plants show a more limited reduction in sugar content in Xf-positive conditions (−20.1%) and combined stresses (−11.1%). Furthermore, while the amount of glucose decreases significantly in stressed Cellina di Nardò plants (≈18%), an increase was observed in Leccino plants under drought/Xf combined stresses (+11.2%). An opposite behavior among cvs was also observed for sucrose, as an accumulation of the disaccharide was recorded in stressed Leccino plants (≈37%). The different response to combined stress by Xf-resistant plants was confirmed considering genes coding for the sucrose or monosaccharide transporter (OeSUT1, OeMST2), the cell wall or vacuolar invertase (OeINV-CW, OeINV-V), the granule-bound starch synthase I (OeGBSSI) and sucrose synthase (OeSUSY), with a higher expression than at least one single stress (e.g., ≈1-fold higher or more than Xf for OeMST2, OeINV-CW, OeINV-V, OeGBSSI). It is probable that the pathways involved in drought stress response induce positive effects useful for pathogen resistance in cv Leccino, confirming the importance of investigating the mechanisms of cross-talk of biotic and abiotic responses.

Conversion of Food Waste into 2,3-Butanediol via Thermophilic Fermentation: Effects of Carbohydrate Content and Nutrient Supplementation

Fermentation of food waste into 2,3-butanediol (2,3-BDO), a high-value chemical, is environmentally sustainable and an inexpensive method to recycle waste. Compared to traditional mesophilic fermentation, thermophilic fermentation can inhibit the growth of contaminant bacteria, thereby improving the success of food waste fermentation. However, the effects of sugar and nutrient concentrations in thermophilic food waste fermentations are currently unclear. Here, we investigated the effects of sugar and nutrients (yeast extract (YE) and peptone) concentrations on 2,3-BDO production from fermenting glucose and food waste media using the newly isolated thermophilic Bacillus licheniformis YNP5-TSU. When glucose media was used, fermentation was greatly affected by sugar and nutrient concentrations: excessive glucose (>70 g/L) slowed down the fermentation and low nutrients (2 g/L YE and 1 g/L peptone) caused fermentation failure. However, when food waste media were used with low nutrient addition, the bacteria consumed all 57.8 g/L sugars within 24 h and produced 24.2 g/L 2,3-BDO, equivalent to a fermentation yield of 0.42 g/g. An increase in initial sugar content (72.9 g/L) led to a higher 2,3-BDO titer of 36.7 g/L with a nearly theoretical yield of 0.47 g/g. These findings may provide fundamental knowledge for designing cost-effective food waste fermentation to produce 2,3-BDO.

NUTRITIONAL VALUE OF GRAIN VARIETIES OF SPRING BARLEY OF TATAR RESEARCH INSTITUTE SELECTION

Four varieties and 3 promising lines of spring barley breeding by Tatar Research Institute of Agriculture were studied for grain nutrition to identify the most promising ones. The work was conducted in 2015-2017 in Predkamye Republic of Tatarstan. Grey forest soil, humus content 3.35-3.52 % (GOST 26213-91), alkaline-hydrolyzable nitrogen 85.0...94.0 mg/kg (by A.H. Kornfield), mobile phosphorus 251...287 and exchangeable potassium 149...167 mg/kg (by Kirsanov; GOST 26207-91). The predecessor is winter rye, the repetition is fourfold, the standard grade is Raushan. It was found that line k-295-12, on average over 3 years, significantly exceeded the standard by 27.77 g in crude protein content; by 20.0 g in digestible protein content and by 7.35 g in digestible protein content per feeding unit. The variability of sugar content in varieties was 30.67 ... 47.0 g, significantly exceeded the standard by 13.33 g variety Tevkech (47.0 g) and by 13.0 g line k-23-13 (46.67 g). The fat content was formed in the standard 19.03 g, varieties Kamashevsky, Endan and lines k-23-23, k-561-13 and k-295-12 exceeded it by 7.47; 5.77; 11.47; 9.84 and 5.67 g, respectively. The exchange energy content in grain ranged from 14.42 MJ of the variety Raushan, to 14.72 MJ of the line k-295-12, with no significant differences between genotypes. In the dry year of 2015, the crude and digestible protein content was 148.0...165.0 and 110.74...118.8 g, respectively, and in 2016 it was 129.00...164.4 and 92.88...118.37 g, respectively. In favorable 2017, the content of crude and digestible protein were lower, the varieties Raushan and Tevkech were characterized by the greatest decrease in crude and digestible protein (65.7 and 67.4 % to the level of 2015). On average over 3 years, the best line was k-295-12 for the set of indicators of grain nutrition