The employment of strontium to activate mouse oocytes: effects on spermatid-injection outcome

The present research investigated the effects of various strontium concentrations, in combination with different incubation periods, on mouse parthenogentic oocyte activation and blastocyst development. The results for blastocyst development showed a trend indicating that 10 mM strontium for 3 h was the optimal strontium protocol. Ethanol, an agent that incites oocyte activation via a monotonic rise in calcium, was employed as a control. The outcome of blastocyst formation arising from parthenogenic ethanol activation was significantly less (P < 0.001) than that achieved by the optimal strontium protocol. To assess the impact of strontium oocyte activation on embryo viability following fertilization with immature germ cells, the protocol of 10 mM strontium for 3 h was applied to oocytes injected with round spermatids and then compared with other protocols. The results indicate that following round-spermatid injection the benefits derived from strontium artificial oocyte activation are evident during both pre- and post-implantation development. However, in order to adjust the protocol to the most effective round-spermatid injection in relation to the oocyte cell cycle, injection was done 1.5 h after strontium activation followed by another 1.5 h activation in strontium. The implementation of round-spermatid injection in combination with this oocyte-activation protocol led to live-birth outcomes not significantly different to those outcomes obtained by mature spermatozoa.     

In vitro antifungal activity and chemical composition of Warionia saharae essential oil against 3 apple phytopathogenic fungi

Essential oil of aerial parts of Warionia saharae was obtained by hydrodistillation and analyzed by GC and GC-MS. Thirty-nine compounds were identified, accounting for 93.2% of the total oil. β-Eudesmol (34.9%), nerolidol-E (23%), and linalool (15.2%) were the most abundant components. The antifungal activity of the W. saharae oil was tested by poisoned food (PF) technique and the volatile activity (VA) assay against 3 phytopathogenic causing the deterioration for apple. The results indicated that the W. saharae oil inhibited significantly the mycelial growth of all strains tested (p<0.05). The minimum inhibitory concentration against Alternaria sp. was 2 μL/mL air in VA assay, whereas >2 μL/mL in PF technique for all strains. Fungal spore production was completely inhibited at 1 μL/mL air for Alternaria sp. and at 2 μL/mL air for Penicillium expansum and Rhizopus stolonifer.     

Antibacterial activity of peptides extracted from tryptic hydrolyzate of whey protein by nanofiltration

Ultrafiltration permeate of whey protein tryptic hydrolyzate was processed by nanofiltration (NF) to obtain retentate (NFR) and permeate (NFP) that were then tested as inhibitors of Listeria, Staphylococcus aureus and Escherichia coli. NFR at 20 mg mL^?1 was most effective as an inhibitor (P < 0.001); whereas E. coli was relatively resistant, the effect on Listeria and S. aureus was greater at 20 mg mL^?1 than at 10 mg mL^?1 (P < 0.01). Peptide analysis revealed that NFR was rich in anionic peptides over eight amino acid residues in length. The antibacterial activity of two anionic peptides (84–91 and 125–135) and a cationic peptide (36–42) derived from β-lactoglobulin was tested. Peptide 125–135 was more inhibitory (P < 0.05) than peptide 84–91 against Listeria monocytogenes and S. aureus; peptide 36–42 was not inhibitory. NFR appears to have potential as a natural bio-preservative.     

Stability of phytochemicals as sources of anti-inflammatory nutraceuticals in beverages — A review

Recently phytochemical constituents have attracted a lot of interest as sources of functional ingredients in food product formulations. However, before being incorporated into foods or beverages the stability of these bioactive constituents during post-harvest preservation procedures, in food matrices and during processing and storage must be considered. This review will focus on the stability of phytochemical constituents of herbs with anti-inflammatory properties, including chamomile, meadowsweet, feverfew and willow. These herbs contain a relatively high content of phenolic compounds in comparison to common fruits and vegetables. They have been traditionally used to make teas or infusions that are consumed as a remedy for pain and inflammation. Effects of preservation and extraction conditions on the level of bioactive constituents will be reviewed. The storage conditions (temperature) and thermal processing at pH levels encountered in food products will also be examined.     

Stability of citral in protein- and gum arabic-stabilized oil-in-water emulsions

Citral is a major flavor component of citrus oils that can undergo chemical degradation leading to loss of aroma and formation of off-flavors. Engineering the interface of emulsion droplets with emulsifiers that inhibit chemical reactions could provide a novel technique to stabilize citral. The objective of this study was to determine if citral was more stable in emulsions stabilized with whey protein isolate (WPI) than gum arabic (GA). Degradation of citral was equal to or less in GA- than WPI-stabilized emulsion at pH 3.0 and 7.0. However, formation of the citral oxidation product, p-cymene was greater in the GA- than WPI-stabilized emulsion at pH 3.0 and 7.0. Emulsions stabilized by WPI had a better creaming stability than those stabilized by GA because the protein emulsifier was able to produce smaller lipid droplets during homogenization. These data suggest that WPI was able to inhibit the oxidative deterioration of citral in oil-in-water emulsions. The ability of WPI to decrease oxidative reactions could be due to the formation of a cationic emulsion droplet interface at pH 3.0 which can repel prooxidative metals and/or the ability of amino acids in WPI to scavenge free radical and chelate prooxidative metals.     

Cover Image,Volume 98, Issue 11

The cover image, by Ciara Duffy et al., is based on the Research Article In vitro evaluation of chitosan copper chelate gels as a multimicronutrient feed additive for cattle, DOI: 10.1002/jsfa.8939 .

     

A novel method for elimination of aflatoxin M1 in milk using Lactobacillus rhamnosus GG biofilm

This study aimed to develop a new method for detoxification of milk from aflatoxin M1 (AFM1) by using Lactobacillus rhamnosus GG biofilm. After inoculation of milk contaminated with AFM1 into L. rhamnosus GG biofilm, the unbound AFM1 was extracted and quantified by HPLC. The stability of the formed AFM1/biofilm complex using different AFM1 contamination levels of milk was also studied. We found that the percentages of bound AFM1 by L. rhamnosus GG biofilm reached up to 60.74%. While no significant difference in milk proteins content was observed after AFM1 binding, some changes in total dry matter and fat content were noticed.     

Evaluation of the effect of processing on cocoa polyphenols: antiradical activity,anthocyanins and procyanidins profiling from raw beans to chocolate

The content and composition of anthocyanins and procyanidins in fermented cocoa beans (from different geographic origins: Ecuador, Cameroon, Ivory Coast, Ghana and Nigeria), roasted nibs, cocoa mass and chocolate were determined, beside the determination of the total antiradical capacity. Concerning geographic origin, cocoa beans and processed products from Ecuador showed the highest levels of anthocyanins, followed by Nigeria and Cameroon. Generally, as cocoa beans were further processed, the levels of anthocyanins and flavan‐3‐ols decreased. The largest observed losses of phenolics occurred during roasting. A progressive decreasing trend in polyphenol concentration was observed in the other processed samples as well. Despite the original content of polyphenols in raw cocoa beans, technological processes imply a significant impact on cocoa quality, confirming the need of specific optimisation to obtain high value chocolate.     

Effect of the cultivation mode on red pigments production from Monascus ruber

In submerged cultures performed in chemically defined fermentation medium containing glucose and glutamate, the growth and production of water‐soluble red pigments and citrinin by the filamentous fungus Monascus ruber were studied under various carbon/nitrogen (C/N) ratios. The specific production of the red pigments was optimal at a glucose/glutamate ratio of about 10 and then steadily decreased at higher C/N ratio. In contrast, the production of the mycotoxin increased with increased C/N with an optimum in the range of 30–45. In a fed‐batch mode, it was also found that the production of pigments was not favoured in fed‐batch mode by feeding the medium with glucose while keeping the C/N ratio lower than 10. This low production likely resulted from concurrent high accumulation of L‐malic acid that was reported to inhibit this production. In contrast, this mode of cultivation was rather favourable for the production of the mycotoxin.