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The aim of this work was to obtain sweet quinoa seeds by a pearling process. Thus, two different pearling degrees (20% and 30%) were tested. Moreover, the effect of pearling process on saponins and phenolic content in quinoa were evaluated. To this end, GC-MS methodology was used to identify and quantify the saponins and reversed phase-high performance liquid chromatography coupled to DAD and mass spectrometer detectors was applied to study the phenolic composition. As expected, whole quinoa had the highest saponins and phenolics contents. An abrasion degree of 30% was necessary to obtain sweet quinoa (with a total saponin content lower than 110 mg/100 g). Obviously, this process caused a decrease of 21.5% and 35.2% of free and bound phenolic compounds, respectively. However, this decrease was lower if compared with other cereals. Thus, pearling process is a promising sustainable method to obtain sweet quinoa with a "green" approach., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The phenolic fraction of virgin olive oil influences both its quality and oxidative stability. One of the principal threats of the quality of olive fruit is the olive fly ( Bactrocera oleae) as it alters the chemical composition. The attack of this olive pest has been studied in order to evaluate its influence on the quality of virgin olive oil (free acidity, peroxide value, fatty acid composition, water content, oxidative stability, phenols, and antioxidant power of phenolic fraction). The study was performed using several virgin olive oils obtained from olives with different degrees of fly infestation. They were acquired in different Italian industrial mills from the Abruzzo region. Qualitative and quantitative analyses of phenolic profiles were performed by capillary electrophoresis-diode array detection, and electrochemical evaluation of the antioxidant power of the phenolic fraction was also carried out. These analyses demonstrated that the degree of fly attack was positively correlated with free acidity ( r = 0.77, p < 0.05) and oxidized products ( r = 0.58, p < 0.05), and negatively related to the oxidative stability index ( r = -0.54, p < 0.05) and phenolic content ( r = -0.50, p < 0.05), mainly with secoiridoid compounds. However, it has been confirmed that the phenolic fraction of olive oil depends on several parameters and that a clear correlation does not exist between the percentages of fly attack and phenolic content.

Among vegetable oils, virgin olive oil (VOO) has nutritional and sensory characteristics that to make it unique and a basic component of the Mediterranean diet. The importance of VOO is mainly attributed both to its high content of oleic acid a balanced contribution quantity of polyunsaturated fatty acids and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of several human diseases. The polar phenolic compounds of VOO belong to different classes: phenolic acids, phenyl ethyl alcohols, hydroxy-isochromans, flavonoids, lignans and secoiridoids. This latter family of compounds is characteristic of Oleaceae plants and secoiridoids are the main compounds of the phenolic fraction. Many agronomical and technological factors can affect the presence of phenols in VOO. Its shelf life is higher than other vegetable oils, mainly due to the presence of phenolic molecules having a catechol group, such as hydroxytyrosol and its secoiridoid derivatives. Several assays have been used to establish the antioxidant activity of these isolated phenolic compounds. Typical sensory gustative properties of VOO, such as bitterness and pungency, have been attributed to secoiridoid molecules. Considering the importance of the phenolic fraction of VOO, high performance analytical methods have been developed to characterize its complex phenolic pattern. The aim of this review is to realize a survey on phenolic compounds of virgin olive oils bearing in mind their chemical-analytical, healthy and sensory aspects. In particular, starting from the basic studies, the results of researches developed in the last ten years will be focused.

A rapid and reliable capillary zone electrophoresis method was used as a tool to obtain both qualitative and quantitative information about simple phenols, lignans, complex phenols (isomeric forms of secoiridoids), phenolic acids, and flavonoids in the solid-phase separation extracts from different Spanish extra-virgin olive oil in a short time (less than 6 min). Peak identification was done by using commercial and HPLC-isolated standards, studying the information of the electropherograms obtained at several wavelengths and also using the information previously reported. For the quantification of lignans and complex phenols (secoiridoid derivatives), we used a reference compound (oleuropein glucoside) at two different wavelengths (200 and 240 nm) and for the quantification of tyrosol and flavonoids, we used their commercially available standards.

Abstract: The aim of this paper was to use the air classification technology to produce barley flours enriched in phenolic compounds and to obtain naturally enriched ingredients for pasta and bakery industry. Phenolic compounds in barley have been described in literature using different methodologies that are not easily comparable. This paper describes a comparative study between different separative and spectrophotometric methods to determine free and bound phenolic compounds in barley flours and their air classified fractions from three different cultivars grown in the same experimental field. To this end, reversed phase-high performance liquid chromatography, micellar electrokinetic chromatography, and spectrophotometric determinations were applied. The barley phenolic compounds analyzed included mainly catechins and proanthocyanidins as free phenols, and hydroxycinnamic acids and their derivatives as bound phenols. The enriched fractions obtained by air classification showed an increase of free flavan-3-ols of 157–173% compared to whole flour. The same fractions also reported larger concentration of bound phenolic compounds (160–236%) with respect to whole flours. Air classification results a good technique to enrich the flours and to utilize the barley co-products. [Copyright &y& Elsevier]

study on the characterization of Tunisian extra-virgin olive oil varieties produced in their place of origin has been carried out. Due to the influence of the genotype and environmental, agronomic and technological factors on the chemical composition of olive oil and its quality, all the olives studied were collected on the same season, and the oil was obtained under the same processing technique. Several analyses were performed to characterize the different olive oils: free acidity, peroxide value, fatty acid composition, radical scavenging activity, Rancimat assay, pigments content and phenolic compounds by HPLC-MS. In order to evaluate all the results obtained (36 parameters for each variety), different statistical analyses were used to discriminate the extra-virgin olive oil varieties: one-way analysis of variance was performed to check significant differences among cultivars ( p ≤ 0.05); PCA was applied to the data showing that variables such as oleic, linoleic, quinic and vanillic acids, apigenin, luteolin, taxifolin, oleuropein aglycon, pinoresinol acetate, elenolic acid and oxidative stability allowed discriminating among the different varieties of extra-virgin olive oil studied. Besides, LDA model was able to classify the samples depending on their geographical origin in Tunisia (North, Centre and South). [ABSTRACT FROM AUTHOR]

Banana passion fruit (Passiflora tripartite L.H. Bailey) is a lesser known species of the genus Passiflora. This fruit typically grows in the Andean region of Ecuador and it is locally known as tumbo, taxo or curuba. The juice of this fruit is highly appreciated in South America. Extracts of banana passion fruit were characterized for their content levels of free and bound phenolic compounds by high performance liquid chromatography coupled to high resolution mass spectrometry detector (HPLC-ESI-TOF-MS). A total of 82 polar compounds classified as phenolic acid derivatives, organic acids, benzophenones, flavan-3-ols, flavonols and flavones were detected in the extracts. The total phenolic content was 2356 mg 100 g−1 dry matter, with the bound phenolic fraction representing 37.7% of total amounts. Flavan-3-ols, such as (epi)catechin, (epi)azfelechin and their derivatives, were the main phenolic compounds in the free phenolic fraction; however, phenolic acids represented the most abundant class of bound phenolic extracts. The antioxidant and hypoglycemic capacities reported for banana passion fruit were higher than for other fruits. To our knowledge, this is the first time that bound phenolic compounds have been described in banana passion fruit pulp. [ABSTRACT FROM AUTHOR]

Abstract: The phenolic compounds present in seven samples of olive fruits were analysed by a rapid and resolutive LC–ESI-TOF MS method. All samples were collected during the normal picking period for olive oil production, in central and south Tunisia, and were obtained from the Oueslati variety cultivated in different olive growing areas. In the Tunisian samples, 22 compounds have been characterised by LC–ESI-TOF MS analysis. Results showed no qualitative differences in the phenolic fractions between virgin olive oils from different geographical region. However, significant quantitative differences were observed in a wide number of phenolic compounds. These results permit to use the phenolic fractions as an indicator of each region. [Copyright &y& Elsevier]

• Addition of polyphenols can mitigate the acrylamide formation in fried potato model. • The added polyphenols are obtained from the olive oil supply chain. • Hydrophobicity and activity of the polyphenols seem to be correlated. • TyAc and HTyAc presented the highest mitigation effects on AA content. • TyAc added to the dough showed around 90 % AA reduction. In order to find innovative protocols to reduce acrylamide (AA), a genotoxin and a probable carcinogen, in foods, several phenolic compounds were considered as additives to a potato derivative. Phenols are obtained from the by-products of the olive production chain. Potato flakes were kneaded with water containing different concentrations of a single phenol: tyrosol (Ty), hydroxytyrosol (HTy), tyrosyl acetate (TyAc), hydroxytyrosyl acetate (HTyAc), caffeic acid and oleuropein. After a cooking step at 175 °C for 4 min, AA was extracted, derivatized with xanthydrol and quantified by GC–MS. The results obtained for Ty, HTy, caffeic acid and oleuropein showed AA reduction ranging from 29 % to 47 %, whereas with TyAc and HTyAc the mitigation effect was noticeably stronger (90 and 75 %). The less polar molecule, TyAc, showed the best inhibition performance. These preliminary results show that phenolic compounds from olive by-products could also be valorized as food starchy additives. [ABSTRACT FROM AUTHOR]