Characterisation of peppermint (Mentha piperita L.) essential oil encapsulates.

Aim: The aim was to choose the optimal encapsulation system and to incorporate encapsulates loaded with essential oil into the ice cream as a model food product. Methods: Ca-alginate beads were produced by electrostatic extrusion process. Gelatine/alginate coacervates were processed with coacervation. Carnauba wax microparticles were produced using melt dispersion process. Morphological properties, chemical, and thermal stabilities of encapsulates were tested by SEM, FTIR spectral, and thermogravimetric analysis. Results: Alginate provided sufficient emulsion stability over 1 h. Ca-alginate showed higher encapsulation efficiency (EE) (98.4 ± 4.3%) compared to carnauba wax (94.2 ± 7.8%) and gelatine/alginate coacervates (13.2 ± 1.2%). The presence of essential oil in all three types of encapsulates confirmed with FTIR. The encapsulation process ensured controlled release and thermal stability of the oil. Conclusions: Ca-alginate matrix as the most suitable for peppermint essential oil encapsulation. The sensory analysis showed that ice cream incorporating encapsulates is a promising system for the consumption of health beneficial peppermint essential oil.

Simultaneous extraction of phenolics and essential oil from peppermint by pressurized hot water extraction.

Phenolics and essential oil of peppermint were obtained by pressurized hot water extraction (PHWE). The best extraction conditions were found to be 130 °C for temperature, 10 min for extraction time, and 3 cycles for extraction number. There were no statistically significant differences between 130 and 160 °C in terms of essential oil content. Total phenolic contents (TPC) of the extracts were higher at 160 °C than that of 130 °C. However, further HPLC analysis of the extracts revealed that hydrolysis and/or decomposition of phenolics were observed in the extracts obtained at 160 °C. The main phenolic of peppermint was determined as eriocitrin by HPLC-DAD, while menthol was the dominant component in essential oil fraction of peppermint by GC-FID. The present study demonstrated that PHWE was a suitable technique for simultaneous extraction of phenolics and essential oil from peppermint. The technique might be used as an analytical extraction tool for determination of phenolics and essential oil. Moreover, the extracts of PHWE could directly be evaluated for the enrichment of liquid food formulations or be transformed into solid form by suitable techniques such as spray drying for easy storage and subsequent enrichment of food products.

Analysis of volatile components of cape gooseberry (Physalis peruviana L.) grown in Turkey by HS-SPME and GC-MS.

Volatile components in cape gooseberry fruit at ripe stage were collected using headspace-solid phase microextraction, and analyzed by gas chromatography-mass spectrometry. Three solid phase microextraction fiber coatings (DVB/CAR/PDMS, CAR/PDMS, and PDMS/DVB) were tested for evaluation of volatile compounds. DVB/CAR/PDMS fiber showed a strong extraction capacity for volatile compounds and produced the best result in case of total peak areas. A total of 133 volatile compounds were identified in fruit pulp; among them 1-hexanol (6.86%), eucalyptol (6.66%), ethyl butanoate (6.47%), ethyl octanoate (4.01%), ethyl decanoate (3.39%), 4-terpineol (3.27%), and 2-methyl-1-butanol (3.10%) were the major components in the sample extracts.

Confirmatory method for the determination of volatile congeners and methanol in Turkish raki according to European Union Regulation (EEC) No. 2000R2870: single-laboratory validation.

A method described by European Union Regulation (EEC) No. 2000R2870 was validated and supported by GC/MS analysis for the determination of volatile congeners and methanol in Turkish raki. The method was validated in terms of specificity, accuracy, precision, LOD, LOQ, linearity, and robustness. The specificity of the method was demonstrated, and the method showed excellent accuracy (97.5-100.1%). Linearity was checked in the ranges of 0.200-26.390 mg/100 mL for more volatile compounds and 1.155-48.00 mg/100 mL for less volatile compounds, after concentrations found in Turkish raki were taken into account. The calibration curves of all analytes showed good linearity (R2 > 0.998). The within- and between-day precision (RSD) values of 11 analytes were in the range of 0.18-4.50%. The LOD and LOQ values were in the range of 0.014-0.362 and 0.045-1.085 mg/100 mL, respectively. The method can be used as an absolute quantification method for the determination of volatile congeners and methanol in Turkish raki and for QC.

Changes in volatile compounds and some physicochemical properties of European cranberrybush (Viburnum opulus L.) during ripening through traditional fermentation.

The changes in volatile compounds and some physicochemical properties of European Cranberrybush (Viburnum opulus L.) were investigated during traditional fermentation. Using the principal component analysis (PCA), relations between volatile compounds and fermentation were associated with dynamics of these compounds. In total, 58 volatile compounds were identified, 3-methylbutanoic acid (25.4% to 66.4% of identified volatile compounds) being the major constituent in raw, 2-, 3-, and 4-mo fermented European Cranberrybush fruits, while 2-octanone was dominant in 1-mo fermented sample with a 30% of the total identified volatiles. The amount of total volatile compounds was increased in the 1st month of fermentation and then decreased gradually in the following months. Acids were the dominant volatile compounds in raw and 3- to 4-mo fermented European Cranberrybush. Ketones and alcohols had the highest percentage in total volatile compounds in the 2nd and 3rd months of fermentation, respectively.

Effect of maceration time on free and bound volatiles of red wines from cv. Karaoglan (Vitis vinifera L.) grapes grown in Arapgir, Turkey.

Skin maceration is an essential winemaking technique that affects sensory properties and aroma of red wines. The aim of this study was to investigate aroma profiles of red wines made from cv. Karaoglan, a grape variety grown in Arapgir (Malatya, Turkey) and the effect of maceration time (5, 10, and 15 d) on free and bound aroma compounds and sensory properties. Three maceration times were applied in durations of 5, 10, and 15 d. Free and glycosidically bound aroma compounds were analyzed using gas chromatography-mass spectrometry (GC-MS) in Karaoglan wines, and the effect of different maceration times on aroma composition were evaluated. Results indicate that extended maceration time significantly influenced the aroma composition of wines both qualitatively and quantitatively. A total of 59 free and 22 bound aroma compounds were identified in the final wines. The maximum of free aroma content was achieved with 5 d of maceration, while 15 d of maceration gave the highest amount of glycosidically bound aroma compounds. From sensorial point of view, the wine produced with 10 d of maceration had the best panel score compared to wines with 5 and 15 d of maceration. This is the first study referring to the composition of aroma compounds of red wines made from cv. Karaoglan. It was concluded that this cultivar resulted in a good quality wine in terms of bound and free aroma compounds. This information of vinification practices that influence the chemical properties of wine is useful for grape growers and winemakers.

Effects of fermentation temperature and aeration on production of natural isoamyl acetate by Williopsis saturnus var. saturnus.

Isoamyl acetate is a natural flavour ester, widely used as a source of banana flavour by the food industry. Williopsis saturnus var. saturnus is a yeast which can produce isoamyl acetate by esterification of amyl alcohols with acetyl coenzyme A via fermentation. The evaluation of this kind of production as an alternative way to obtain natural banana flavour could be possible, if the levels produced were high enough to make a commercial product. In this study, the effects of temperature (15°C and 25°C) and aeration (aerobic, semiaerobic, and anaerobic) on the production of isoamyl acetate by Williopsis saturnus var. saturnus from sugar beet molasses were examined. According to the results obtained, isoamyl acetate production rate and specific productivity were higher at 25°C than at 15°C and at semiaerobic condition than aerobic and anaerobic conditions. Williopsis saturnus var. saturnus showed a production rate of 0.703 mg (-1) h(-1) and a specific productivity of 0.0297 mg L(-1) cell(-1) h(-1) isoamyl acetate with semiaerobic condition at 25°C. The maximum amount of isoamyl acetate reached with these conditions was 118 mg/L.

Survival of Lactobacillus acidophilus LA-5 and Bifidobacterium bifidum BB-02 in white-brined cheese.

The viability of probiotic cultures used as adjunct cultures including Bifidobacterium bifidum BB-02 and Lactobacillus acidophilus LA-5 in white-brined cheese was investigated. The microbiological and biochemical properties of cheeses were assessed throughout 90 days of storage. Two inoculum rates for probiotic starters (2.5% and 5.0%, v/v, corresponding to (1.0-1.3)x10(9) cfu/g and (2.0-2.1)x10(9) cfu/g, respectively) were compared with the control cheese. Results obtained showed that a higher inoculum rate resulted in faster proteolysis. The cheese inoculated with 5% probiotic strains had higher water-soluble nitrogen, non-protein nitrogen, proteose-peptone nitrogen and tyrosine values than the other experimental cheeses. At the end of storage, the cheese supplemented with 5% probiotic culture had a ripening coefficient of 28.3%, followed by 2.5% probiotic strains containing the sample being 24.9%, and the control being 23.6%, respectively. It was also found that the colony counts of both probiotic microorganisms declined during storage. After 90 days of storage, the number of probiotic colonies were still around the threshold for a minimum probiotic effect (10(6) cfu/g).