Predictive Evaluation of Microbiological Stability of Soft Drinks with Lycium barbarum L. Stored at Temperature Shifts.

Lycium barbarum L., used in Chinese traditional medicine for centuries, has gained popularity in Europe in the last decade because of its health-promoting properties assigned to phenolic compounds and antioxidant activity. Goji fruits and extracts are often used as ingredients in popular homemade milk cocktails. Within this study, the microbiological stability of the milkshake, with the addition of berries from NingXia Province and their extract, was evaluated using the ComBase® prognostic model. The extraction of dry berries in water at 70 °C for 72 h produced an extract showing radical inhibition of 64.9% and a total phenol content of 63.6 mg g-1. The phenolic compounds with the highest concentrations were in turn: 3-hydroxybenzoic acid, gallic acid, procyanidin B2, and catechin. The milkshake inoculated with the reference B. subtilis was a model for the study of its microbiological stability. Using ComBase®, a microbiological response to the delayed cooling of goji berry extract and the milkshake with the addition of goji berries was predicted and the model's accuracy assessed. The best-performing models were constructed for extract (Bias factor Bf 1.33, Accuracy factor Af 3.43) and milkshake (Bf 1.29, Af 1.65) in a profile simulating delayed refrigeration (22.5 °C-9 °C-23 °C). Despite discrepancies between predicted and observed bacterial growth due to the antimicrobial effect of the derivatives of goji berries, the models were validated as "overpredict", i.e., "fail safe", and may be used to prognose the stability of these products in the given temperature profile.

Microfluidic preparation of antimicrobial microparticles composed of l-lactide/1,3-dioxolane (co)polymers loaded with quercetin.

The resistance of microorganisms against commonly used antibiotics is becoming an increasingly important problem in the food and pharmaceutical industries. Therefore, the development of novel bactericidal agents, as well as the design of drug delivery systems based on materials composed of biocompatible and biodegradable building blocks, has attracted increasing attention. To address this challenge, microparticles composed of l-lactide homopolymer and l-lactide/1,3-dioxolane (co)polymers loaded with quercetin (Q) were fabricated by using a microfluidic technique. This method enables the preparation of homogeneous particles with sizes ranging from 60 to 80 µm, composed of degradable semicrystalline or amorphous (co)polyesters. The microencapsulation of Q in a (co)polymeric matrix enables prolonged release of the antimicrobial agent. The antibacterial properties of the obtained biocompatible microparticles are confirmed by the agar diffusion plate method for various bacterial strains. Therefore, Q-loaded microparticles can have important applications in food preservation as a novel antimicrobial system.

Chemical and Biological Characteristics of Oxytropis pseudoglandulosa Plant of Mongolian Origin.

Oxytropis pseudoglandulosa is used in Mongolian traditional medicine due to its numerous reported health-promoting effects. To date, there are very few scientific reports that describe this species. In this article, its volatile oil composition, lipid extract composition, total phenolic and flavonoid content, antibacterial and allergenic properties are elucidated for the first time. Hexadecanoic acid, fokienol and tricosane were determined as the most notable components of the volatile oil, at 13.13, 11.46 and 5.55%, respectively. Methyl benzoate was shown to be the most abundant component of lipid extract at 40.69, followed by (E)-prop-2-enoic acid, 3-phenyl- and benzenepropanoic acid, at 18.55 and 9.97%. With a TPC of 6.620 mg GAE g-1 and TFC of 10.316 mg QE g-1, the plant extract of O. pseudoglandulosa indicated good antioxidant activity measured by IC50 at 18.761 µg mL-1. Of the 12 tested microorganisms, B. subtilis and S. cerevisiae were the shown to be most susceptible to the plant extract, with MIC at 2.081 and 0.260% (v/v), respectively. Bet v 1-a major birch pollen allergen found in plant-based foods-was determined to be at 192.02 ng g-1 with ELISA. Such a wide spectrum of biological activity indicated by O. pseudoglandulosa lends credence for its application in food industry. Its exerted antioxidant and antimicrobial effects could improve preservation of low-processed food dedicated for consumers afflicted with allergies. Hexadecanoic acid supplemented in foods with dietary plant extracts could add to the potential anti-inflammatory impact. The analysis of lipid makeup suggests O. pseudoglandulosa extract could also be considered as natural pesticide in organic farming.

Chemical and Biological Profile and Allergenicity of Thymus baicalensis Plant of Mongolian Origin.

Thymus baicalensis is a medicinal plant recognized as a traditional Mongolian therapeutic and health-promoting food supplement. The aim of the study was to check the suitability of the tested plant for supporting the treatment of certain diseases. The following study is the first one to showcase the versatile scope of characteristics of T. baicalensis, including its volatile oil composition, polyphenolic composition, lipid composition, phenolic and flavonoid contents, antioxidant activity, antimicrobial properties and ingestive allergenicity. Myrcene, at 26.15%, was shown to be the most abundant component of the volatile oil. Compounds known as inherent components of the Thymus genus: thymol and carvacrol made up only about 0.24% of the extracted oil. As much as 10.11 g kg-1 of polyphenol compounds were identified as derivatives of luteolin-7-O-glucuronide. The lipid extract was found to be rich in palmitic acid (31.05%), while unsaturated fatty acids were not reported. Spectrophotometric determination of the phenols and flavonoids indicated 7.541 mg of gallic acid g-1 and 4.345 mg of quercitin g-1, respectively. The free radical scavenging activity was determined by the 2,2-difenylo-1-pikrylohydrazyl method at IC50 = 206.97 µg mL-1. The extracts also had a strong inhibitory effect on M. flavus and P. fluorescenes bacteria, as well as S. cerevisiae yeasts. The Bet v 1 and profilin allergens in T. baicalensis were reported at 175.17 ng g-1 and 1.66 ng g-1, respectively.

Olive Oil with Ozone-Modified Properties and Its Application.

Olive oil application in the cosmetic industry may be extended by its ozonation, bringing about new oil properties and increased stability. Olive oil treated with 0.04 mole O3 or 0.10 mole O3 per 100 g oil was subjected to chemical parameters evaluation and composition scrutinizing by gas chromatography-mass spectrometry (GC-MS) and headspace solid-phase microextraction (HS-SPME) GC-MS analysis. The biological activity of refined and ozonated oil included their antimicrobial properties by the agar diffusion method and cytotoxicity by the MTT assay towards two normal (LLC-PK1, HaCaT) and two cancerous (Caco-2, HeLa) cell lines. The oils served as the basis in cosmetic emulsions. The chosen organoleptic features, preservative efficacy in a challenge test, and persistency during six months of these formulations were assessed. However, the ozonation of the olive oil resulted in a decrease in unsaturated acids; several additional compounds were detected in the ozonated oil, which positively affect the physicochemical, sensory, and functional properties of cosmetic emulsions. Emulsions based on the ozonated olive oil retain their properties longer compared to emulsions based on the refined olive oil. Ozonated oil treated with 0.10 mole O3/100 g oil allowed increasing the shelf life of the non-preserved formulation up to six months. A weak inhibitory effect against Candida albicans and Aspergillus brasiliensis was also demonstrated for this emulsion in the challenge test. Moreover, an interesting aroma, slightly enhanced antimicrobial activity against Escherichia coli, Staphylococcus aureus, C. albicans, A. brasiliensis, and a lack of cytotoxicity at concentrations 625 µg mL-1 make the ozonated olive oil a promising raw material for the cosmetics and pharmaceutical industries.

Clove Oil (Syzygium aromaticum L.) Activity against Alicyclobacillus acidoterrestris Biofilm on Technical Surfaces.

Acidotermophilic bacteria Alicyclobacillus acidoterrestris is one of the main contaminants in the fruit industry forming biofilms which are difficult to remove from the production line by conventional methods. An alternative approach aims for the use of essential oils to prevent Alicyclobacillus biofilm development. The effect of clove essential oil on A. acidoterrestris biofilms on glass and polyvinyl chloride surfaces under static and agitated culture conditions was investigated by atomic force microscopy and the plate count method. The medium-flow and the type of technical surface significantly influenced A. acidoterrestris biofilm. The PVC was colonized in a greater extent comparing to glass. Clove essential oil in 0.05% (v/v) caused 25.1-65.0% reduction of biofilms on the technical surfaces along with substantial changes in their morphology by a decrease in the biofilm: height, surface roughness, and surface area difference. The oil also induced alteration in individual bacterial cells length and visible increase of their roughness. Clove essential oil seems to release EPS from biofilm and thus induce detachment of bacteria from the surface. Due to anti-A. acidoterrestris biofilm activity, the clove oil may be used in the juice industry to hinder a development of A. acidoterrestris biofilms on production surfaces.