In house validated UHPLC protocol for the determination of the total hydroxytyrosol and tyrosol content in virgin olive oil fit for the purpose of the health claim introduced by the EC Regulation 432/2012 for \u201cOlive oil polyphenols\u201d

An ongoing challenge in olive oil analytics is the development of a reliable procedure that can draw the consensus of all interested parties regarding the quantification of concentrations above the required minimum value of 5 mg of bioactive "olive oil polyphenols" per 20 g of the oil, to fulfill the health claim introduced by the European Commission (EC) Regulation 432/2012. An in-house validated ultra-high performance liquid chromatography (UHPLC) protocol fit for this purpose is proposed. It relies on quantification of the total hydroxytyrsol (Htyr) and tyrosol (Tyr) content in the virgin olive oil (VOO) polar fraction (PF) before and after acidic hydrolysis of their bound forms. PF extraction and hydrolysis conditions were as previously reported. The chromatographic run lasts ~1/3 of the time needed under high performance liquid chromatography (HPLC) conditions, this was also examined. Eluent consumption for the same piece of information was 6-fold less. Apart from being cost effective, a larger number of samples can be analyzed daily with less environmental impact. Two external curves, detection at 280 nm and correction factors for molecular weight difference are proposed. The method, which is fit for purpose, is selective, robust with satisfactory precision (percentage relative standard deviation (%RSD) values < 11%) and recoveries higher than 87.6% for the target analytes (Htyr, Tyr). Standard operational procedures are easy to apply in the olive oil sector

Shifting sowing of camelina from spring to autumn enhances the oil quality for bio-based applications in response to temperature and seed carbon stock

Camelina [Camelina sativa (L.)Crantz]is an emerging oilseed crop that is attracting the interest of farmers in relation to its high environmental adaptability and low-input request. Camelina oil is an outstanding feedstock for the bio-based industry, since its unique composition allows multiple applications. Being spring camelina biotypes able to grow as both an autumn and spring crop in mild climates, and sowing date directly influences the temperature occurring during the seed filling stage, which likewise influences the final seed quality in terms of seed weight, oil and fatty acid (FA)content. A detailed study on the response of spring camelina to the effects of autumn and spring sowing is reported herein. The spring variety Midas was sown at six different sowing dates at the experimental farm of Bologna University (Italy)during two consecutive growing seasons (2015-16 and 2016-17). In parallel, three experiments were also carried out in a growth chamber with different ranges of temperatures during the seed filling period. Samplings of immature seeds over time, in both controlled environment and open field trials, allowed identification of a \u201ctime frame\u201d in which the main variations in FA kinetics occurred. A \u201ccritical period\u201d, from 350 to 540 growing degree day after the start of flowering (GDD-AF)was identified as that in which the closest relation between the final camelina FA composition and temperature, during the seed filling stage, occurred. The adoption of this empirical model permitted early evaluation (about 10 d before harvest)of the final camelina oil composition with relevant implications for the bio-based industry. Autumn sowing dates were associated with increased plant aboveground biomass, seed yield, seed oil content, seed weight (TKW), and content of linolenic and eicosenoic acid. Since eicosenoic acid is a valuable feedstock for the bio-based industry, growing spring camelina, as an autumn crop, in the Mediterranean region allows significantly increase the quantity of this infrequent FA

Toward a harmonized and standardized protocol for the determination of total hydroxytyrosol and tyrosol content in virgin olive oil (VOO). The pros of a fit for the purpose ultra high performance liquid chromatography (UHPLC) procedure

\u3a4oward a harmonized and standardized procedure for the determination of total hydroxytyrosol and tyrosol content in virgin olive oil (VOO), the pros of a recently published in house validated ultra high performance liquid chromatography (UHPLC) protocol are discussed comparatively with those of other procedures that determine directly or indirectly the compounds hosted under the health claim on "olive oil polyphenols" (EC regulation 432/2012). Authentic VOOs were analyzed with five different liquid chromatographic separation protocols and 1H-NMR one in five different laboratories with expertise in VOO phenol analysis within three months. Data comparison indicated differences in absolute values. Method comparison using appropriate tools (Passing-Bablok regression and Bland Altman analyses) for all protocols vs. the UHPLC one indicated slight or statistically significant differences. The results were also discussed in terms of cost effectiveness, detection means, standard requirements and ways to calculate the total hydroxytyrosol and tyrosol content. Findings point out that the in-house validated fit for the purpose UHPLC protocol presents certain pros that should be exploited by the interested parties. These are the simplicity of sample preparation, fast elution time that increase the number of samples analyzed per day and integration of well-resolved peaks with the aid of only two commercially available external standards. Importance of correction factors in the calculations is stressed

Influence of open-air rearing on fatty acid composition and sensory properties of rabbit meat

[EN] A study was conducted to evaluate the fatty acid (FA) composition and sensory properties of meat from rabbits housed in the open-air in movable colony cages on pasture during the fattening period. A total of 60 rabbits were reared using conventional husbandry practises and subsequently divided into two groups at a live weight of about 2.0 kg and at 62 days old. The indoor group was kept in conventional bi-cellular cages (2 animals per cage, 0.07 m2 per rabbit), while the open-air group was reared in movable colony cages (6 animals per cage, 0.17 m2 per rabbit) on a polyphyta natural pasture. The grass was cut on the pasture prior to moving the cages so that the rabbits would not be able to eat the grass. Both groups were fed ad libitum a commercial diet for fattening rabbits. The rabbits were slaughtered when 13 weeks old. Fourteen carcasses from each experimental group were randomly collected and hind leg and loin meat were used to determine the intramuscular lipid content, FA composition and sensory attributes. Rabbits housed open-air in movable cages exhibited lower carcass weight (1110 vs 1243 g; P<0.01) and lipid content of the hind leg meat (3.61 vs 5.18%; P<0.01) as well as a higher content of PUFA (36.9 vs 32.5%; P<0.05) and arachidonic acid (5.9 vs 1.9%; P<0.05). However, no differences were found in the n-6/n-3 PUFA ratio. The quantitative descriptive analyses of the meat (Longissimus lumborum muscle) sensory properties did not show any differences between the experimental groups.Research supported by Italian National Research Council.Cavani, C.; Bianchi, M.; Petracci, M.; Toschi, T.; Parpinello, G.; Kuzminsky, G.; Morera, P.... (2004). Influence of open-air rearing on fatty acid composition and sensory properties of rabbit meat. World Rabbit Science. 12(4):247-258. doi:10.4995/wrs.2004.568SWORD24725812

Phenol content related to antioxidant and antimicrobial activities of Passiflora spp. Extracts

Methanolic extracts were prepared from different organs of plants from five Passiflora species obtained by zygotic embryo culture and evaluated for their capacity to quench DPPH and ABTS+ radicals in comparison to that of Trolox, a water soluble vitamin-E analogue. Moreover their antimicrobial activity against E. coli was tested by agar diffusion and turbidity assays. P. nitida, P. foetida, and P. palmeri showed antimicrobial activity. P. nitida and P. palmeri also showed high antioxidant activity. P. tenuifila and P. coriacea demonstrated antioxidant power but not antimicrobial activity. The phenolic content of the different extracts was studied and quantified by spectrophotometric methods, HPLC, and mass spectrometry. High antioxidant activity correlated with high amounts of o-diphenol and catechin. An unknown component, tentatively identified as structural isomer of isoschaftoside, appeared to correlate with antimicrobial activity