Proso Millet (Panicum miliaceum L.) as Alternative Source of Starch and Phenolic Compounds: A Study on Twenty-Five Worldwide Accessions.

Proso millet has been proposed as an effective anti-diabetic food thanks to the combined action of polyphenols and starch. This study aimed to characterize the chemical composition of twenty-five accessions, in order to enhance this cereal as an alternative to available starch for food applications or to propose new food ingredients with health benefits. Proso millet contained a high percentage of starch, reaching values of 58.51%. The amylose content showed high variability, with values ranging from 1.36 to 42.70%, and significantly higher values were recorded for the white accessions than for the colored ones. High-resistant starch content (13.41-26.07%) was also found. The HPLC-MS analysis showed the same phenolic pattern in all the samples. Cinnamic acids are the most abundant compounds and significant differences in their total content were found (0.69 to 1.35 mg/g DW), while flavonoids were only detected in trace amounts. Statistical results showed significantly higher antiradical activity in the colored accessions than in the white ones.

Within-Plant Variation in Rosmarinus officinalis L. Terpenes and Phenols and Their Antimicrobial Activity against the Rosemary Phytopathogens Alternaria alternata and Pseudomonas viridiflava.

This study investigated within-plant variability of the main bioactive compounds in rosemary (Rosmarinus officinalis L.). Volatile terpenes, including the enantiomeric distribution of monoterpenes, and phenols were analyzed in young and mature foliar, cortical and xylem tissues. In addition, antimicrobial activity of rosmarinic acid and selected terpenes was evaluated against two rosemary pathogens, Alternaria alternata and Pseudomonas viridiflava. Data showed that total concentration and relative contents of terpenes changed in relation to tissue source and age. Their highest total concentration was observed in the young leaves, followed by mature leaves, cortical and xylem tissues. Rosmarinic acid and carnosic acid contents did not show significant differences between leaf tissues of different ages, while young and mature samples showed variations in the content of four flavonoids. These results are useful for a more targeted harvesting of rosemary plants, in order to produce high-quality essential oils and phenolic extracts. Microbial tests showed that several terpenes and rosmarinic acid significantly inhibited the growth of typical rosemary pathogens. Overall, results on antimicrobial activity suggest the potential application of these natural compounds as biochemical markers in breeding programs aimed to select new chemotypes less susceptible to pathogen attacks, and as eco-friendly chemical alternatives to synthetic pesticides.

Formulation of a Phenol-Rich Extract from Unripe Olives (Olea europaea L.) in Microemulsion to Improve Its Solubility and Intestinal Permeability.

The beneficial properties of phenolic compounds from Olea europaea L. are well-known. An olive extract (OE) was prepared from unripe olives (Moraiolo cultivar). The study aimed to formulate OE into a microemulsion (ME) in oral dosage form. OE was extracted from olives with EtOH:H2O (80:20) and characterized by HPLC-DAD. ME composition was stated by a solubility and pseudo-ternary diagram. The ME was chemically and physically characterized, and its stability at 4 °C was analyzed for three months. The ability of the formulation to ameliorate the solubility and the intestinal permeability of OE was evaluated by a Parallel Artificial Membrane Permeability Assay (PAMPA) assay and Caco-2 cells. The total phenolic content of the extract was 39% w/w. The main constituent was oleuropein (31.0%), together with ligstroside (3.1%) and verbascoside (2.4%). The ME was prepared using Capryol 90 as the oily phase, and Cremophor EL and Transcutol (2:1) as surfactant and co-surfactant, respectively. ME droplet size was 14.03 ± 1.36 nm, PdI 0.20 ± 0.08, ζ-potential -1.16 ± 0.48. Stability of ME was confirmed for at least three months. The formulation was loaded with 35 mg/mL of OE, increasing the solubility of the extract by about four times. The enhanced permeability of OE was evaluated by PAMPA, as demonstrated by the Pe value (1.44 ± 0.83 × 10-6 cm/s for OE hydroalcoholic solution, 3.74 ± 0.34 × 10-6 cm/s for OE-ME). Caco-2 cell transport studies confirmed the same results: Papp was 16.14 ± 0.05 × 10-6 cm/s for OE solution and 26.99 ± 0.45 × 10-6 cm/s for OE-ME. ME proved to be a suitable formulation for oral delivery.

A Study on the Biodiversity of Pigmented Andean Potatoes: Nutritional Profile and Phenolic Composition.

The characterization of six varieties of native Andean potatoes with a wide biodiversity in tuber shape, flesh, and skin color was performed, through the determination of their proximate composition, mineral content, and phenolic profile. Minerals concentration revealed significant genotypic variation. Potassium was the most abundant element in all varieties, ranging from 7272.9 to 13,059.9 µg/g and from 12,418 to 17,388.6 µg/g dried weight for the flesh and skin samples, respectively. Iron content was relevant, ranging from 20.5 to 39.9 µg/g and from 112.2 to 288.8 µg/g dried weight in flesh and skin samples, respectively. Phenolic compounds were consistently higher in the skin than in the flesh. The total content varied greatly from 19.5 to 2015.3 µg/g and from 1592.3 to 14807.3 µg/g dried weight for flesh and skin tissues, respectively. 5-caffeoylquinic acid was 74% of the total phenolic acids. Different pattern of anthocyanins was found, depending on the color of the variety; the red genotypes contained predominantly pelargonidin derivatives, while the purple samples had petunidin as a major anthocyanidin. This study increases the knowledge of the composition of the local Andean varieties (which are only scarcely studied so far), helping to enhance these genotypes and the conservation of biodiversity.

The EFSA Health Claim on Olive Oil Polyphenols: Acid Hydrolysis Validation and Total Hydroxytyrosol and Tyrosol Determination in Italian Virgin Olive Oils.

The health claims of olive oil represent an important marketing lever in raising the willingness to pay for a product, but world producers of extra virgin olive oil (EVOO) do not take advantage of it because there are still obstacles to their use. Among these, one issue is the lack of an official method for determination of all free and linked forms derived from secoiridoidic structures of hydroxytyrosol and tyrosol. In this study, different acidic hydrolytic procedures for analyzing the linked forms were tested. The best method was validated and then applied to more than 100 EVOOs. The content of oleuropein and ligstroside derivatives in EVOOs was indirectly evaluated comparing the amount of phenols before and after hydrolysis. After acidic hydrolysis, a high content of total tyrosol was found in most of the EVOOs. The use of a suitable corrective factor for the evaluation of hydroxytyrosol allows an accurate determination only using pure tyrosol as a standard. Further knowledge on the concentration of total hydroxytyrosol will assist in forecasting the resistance of oils against aging, its antioxidant potential and to better control its quality over time.

Study on a Fermented Whole Wheat: Phenolic Content, Activity on PTP1B Enzyme and In Vitro Prebiotic Properties.

Fermented cereals, staple foods in Asia and Africa, are recently receiving a growing interest in Western countries. The object of this work is the characterization of a fermented wheat used as a food ingredient and dietary supplement. To this aim, the phenolic composition, the activity on protein tyrosine phosphatase 1B (PTP1B), an enzyme overexpressed in type-II diabetes, the in vitro prebiotic properties on Lactobacillus reuteri and the microbial composition were investigated. Basic and acidic hydrolysis were tested for an exhaustive recovery of bound phenols: the acidic hydrolysis gave best yields. Methyl ferulate and neocarlinoside were identified for the first time in wheat. The inhibitory power of the extracts of several batches were investigated on PTP1B enzyme. The product was not able to inhibit the enzyme, otherwise, for the first time, a complete inhibition was observed for schaftoside, a major C-flavonoid of wheat. The microbial composition was assessed identifying Lactobacillus, Enterococcus, and Pediococcus as the main bacterial species. The fermented wheat was a suitable substrate for the grown of L. reuteri, recognized for its health properties in the human gut. The proposed method for phenols is easier compared to those based on strong basic hydrolysis; our results assessed the bound phenols as the major fraction, differently from that suggested by the literature for fermented cereals.

Effects of Olive and Pomegranate By-Products on Human Microbiota: A Study Using the SHIME® in Vitro Simulator.

Two by-products containing phenols and polysaccharides, a "pâté" (OP) from the extra virgin olive oil milling process and a decoction of pomegranate mesocarp (PM), were investigated for their effects on human microbiota using the SHIME® system. The ability of these products to modulate the microbial community was studied simulating a daily intake for nine days. Microbial functionality, investigated in terms of short chain fatty acids (SCFA) and NH4+, was stable during the treatment. A significant increase in Lactobacillaceae and Bifidobacteriaceae at nine days was induced by OP mainly in the proximal tract. Polyphenol metabolism indicated the formation of tyrosol from OP mainly in the distal tract, while urolithins C and A were produced from PM, identifying the human donor as a metabotype A. The results confirm the SHIME® system as a suitable in vitro tool to preliminarily investigate interactions between complex botanicals and human microbiota before undertaking more challenging human studies.

Characterization and comparison of cold brew and cold drip coffee extraction methods.

BACKGROUND: Each region of the world has its own methods, protocols, instruments and procedures regarding how to brew coffee. The final result in the cup is strongly affected by the extraction method, and many studies have focused on this subject. However, few studies have investigated slow, cold extraction methods, despite their popularity among baristas. Therefore, the present study aimed to characterize and compare two cold extraction methods: cold brew and cold drip. RESULTS: Physical and chemical analyses were used to describe coffee beverages in terms of pH, total solids, refractive index, density and viscosity. Caffeine and cinnamic acids were quantified using high-performance liquid chromatography (HPLC)/diode array detector and HPLC/mass spectrometry. A sensory evaluation included aroma, flavor and textural attributes. CONCLUSIONS: Significant differences were found in the chemical and physical parameters, both between and within the two methods, as a function of the extraction temperature and contact time. Similarly, the sensory evaluation found differences in flavor profiles, as measured in terms of bitterness, sweetness, sourness and global intensity. © 2018 Society of Chemical Industry.

Recovery and stability over time of phenolic fractions by an industrial filtration system of olive mill wastewaters: a three-year study.

BACKGROUND: The recovery of phenolic compounds from olive milling is recognized as strategic for producers. The aim of this work was to evaluate the quality and stability of retentates obtained from olive mill wastewaters treated with a membrane filtration system constituted by a micro-, ultra- and nanofiltration, followed by a final reverse osmosis, over three crop seasons. Efficiency was evaluated in terms of phenolic amount in the retentates and of organic load in the final discarded waters. Phenolic compounds were quantified using tyrosol as external standard. RESULTS: Our study highlighted a reproducibility of the process over years and a low organic load in permeates from reverse osmosis. Hydroxytyrosol was very stable in the liquid products at 18-28 °C over 24 months of storage. The retentates from reverse osmosis showed the highest phenolic content (78.6 mg g-1 dry matter in 2015), associated with a potassium content of 22 g kg-1 . CONCLUSIONS: The liquid concentrated retentates showed an unexpected stability over time of their bioactive phenolic compounds, particularly of hydroxytyrosol. These samples recovered from olive mill wastewaters can be good sources of natural antioxidants and potassium to guarantee the correct intake and to formulate new food ingredients or food products. © 2017 Society of Chemical Industry.

Anti-Dermatophyte and Anti-Malassezia Activity of Extracts Rich in Polymeric Flavan-3-ols Obtained from Vitis vinifera Seeds.

Several human skin diseases are associated with fungi as dermatophytes and Malassezia. Skin mycoses are increasing and new alternatives to conventional treatments with improved efficacy and/or safety profiles are desirable. For the first time, the anti-dermatophytes and the anti-Malassezia activities of Vitis vinifera seed extracts obtained from different table and wine cultivars have been evaluated. Geometric minimal inhibitory concentration ranged from 20 to 97 µg/mL for dermatophytes and from 32 to 161 µg/mL for Malassezia furfur. Dried grape seed extracts analyzed by HPLC/DAD/ESI/MS showed different quali-quantitative compositions in terms of monomeric and polymeric flavan-3-ols. The minimal inhibitory concentrations for Trichophyton mentagrophytes and for M. furfur were inversely correlated with the amount of the polymeric fraction (r = -0.7639 and r = -0.7228, respectively). Differently, the antifungal activity against T. mentagrophytes was not correlated to the content of flavan-3-ol monomers (r = 0.2920) and only weakly correlated for M. furfur (r = -0.53604). These results suggest that extracts rich in polymeric flavan-3-ols, recovered from V. vinifera seeds, could be used for the treatment of skin fungal infections. Copyright © 2016 John Wiley & Sons, Ltd.

Rosmarinic acid prevents lipid peroxidation and increase in acetylcholinesterase activity in brain of streptozotocin-induced diabetic rats.

We investigated the efficacy of rosmarinic acid (RA) in preventing lipid peroxidation and increased activity of acetylcholinesterase (AChE) in the brain of streptozotocin-induced diabetic rats. The animals were divided into six groups (n = 8): control, ethanol, RA 10 mg/kg, diabetic, diabetic/ethanol and diabetic/RA 10 mg/kg. After 21 days of treatment with RA, the cerebral structures (striatum, cortex and hippocampus) were removed for experimental assays. The results demonstrated that the treatment with RA (10 mg/kg) significantly reduced the level of lipid peroxidation in hippocampus (28%), cortex (38%) and striatum (47%) of diabetic rats when compared with the control. In addition, it was found that hyperglycaemia caused significant increased in the activity of AChE in hippocampus (58%), cortex (46%) and striatum (30%) in comparison with the control. On the other hand, the treatment with RA reversed this effect to the level of control after 3 weeks. In conclusion, the present findings showed that treatment with RA prevents the lipid peroxidation and consequently the increase in AChE activity in diabetic rats, demonstrating that this compound can modulate cholinergic neurotransmission and prevent damage oxidative in brain in the diabetic state. Thus, we can suggest that RA could be a promising compound in the complementary therapy in diabetes.

Phenolic distribution in liquid preparations of Vaccinium myrtillus L. and Vaccinium vitis idaea L.

INTRODUCTION: Liquid preparations such as tinctures and 'bud extracts' of bilberry and lingonberry are typical products used in some European countries but they have not been widely studied to date. OBJECTIVE: Our aim was to define a phytochemical profile in terms of phenolic compounds for liquid preparations of Vaccinium myrtillus L. (bilberry) and Vaccinium vitis idaea L. (lingonberry) foliar tissues, and evaluate their stability. METHODS: Up to 17 extracts of lingonberry, and bilberry have been analysed by HPLC equipped with a diode-array detector (DAD) in combination with MS. Some of these samples were freshly prepared (laboratory extracts). RESULTS: Phenolic profiles of the bud extracts and tinctures of bilberry and lingonberry were obtained at 330 nm, typical of the cinnamoyl compounds and suitable to distinguish these two species. Analogously, the profiles at 280 nm were used to detect the arbutin derivatives recognised as the typical markers of lingonberry leaves only. Among the cinnamoyl derivatives, chlorogenic acid was the main compound found in bilberry samples, while caffeoyl arbutin was the principal marker in lingonberry samples. In quantitative terms, the hydroxycinnamic acids were the main class in bilberry bud extracts ranging between 4.67 and 6.81 mg/L (from 52 to 84% of the total phenols). The young sprouts of this species, independently from the extraction mixture, show a higher phenolic content than adult leaves of the same plant. CONCLUSIONS: The analytical method allowed to define fingerprints of bilberry and lingonberry liquid preparations. Moreover, without applying accelerated ageing protocols, the stability over time of 11 samples was evaluated up to 6 months, demonstrating negligible variations.

Industrial drying for agrifood by-products re-use: Cases studies on pomegranate peel (Punica granatum L.) and stoned olive pomace (pâtè, Olea europaea L.).

The effect of industrial drying processes on phenols and polysaccharides of olive pomace (pâté) and pomegranate peel was studied, with the aim to re-use pomegranate and olive oil by-products. Pomegranate peel (Wonderful and G1 varieties) was oven-dried at different temperatures, taking into account peel thickness and size. Pâté was freeze-dried and oven dried at 50-110 °C, at lab scale; then, an industrial drying system (150 °C) was compared to freeze-drying. All dried samples were analyzed in terms of phenolic and polysaccharides compounds. Drying at room temperature of small pieces of pomegranate peel guaranteed the highest humidity removal and recovery of phenols. Sugar analysis, DLS and 1H NMR confirmed that polysaccharide fractions were not significantly affected by the highest drying temperatures (42 °C for pomegranate, 150 °C for pâté). The two drying procedures at large scale were suitable for avoiding degradation of phenols, maintaining the same profiles of the corresponding freeze-dried samples.

Study of Mono and Di-O-caffeoylquinic Acid Isomers in Acmella oleracea Extracts by HPLC-MS/MS and Application of Linear Equation of Deconvolution Analysis Algorithm for Their Characterization.

Chlorogenic acids, the esters of caffeic and quinic acids, are the main phenolic acids detected in Acmella oleracea extracts and have gained increasing interest in recent years due to their important biological activities. Given their structural similarity and instability, the correct analysis and identification of these compounds in plants is challenging. This study aimed to propose a simple and rapid determination of the A. oleracea caffeoylquinic isomers, applying an HPLC-MS/MS method supported by a mathematical algorithm (Linear Equation of Deconvolution Analysis (LEDA)). The three mono- and the three di-caffeoylquinic acids in roots of Acmella plants were studied by an ion trap MS analyzer. A separation by a conventional chromatographic method was firstly performed and an MS/MS characterization by energetic dimension of collision-induced dissociation mechanism was carried out. The analyses were then replicated using a short HPLC column and a fast elution gradient (ten minutes). Each acquired MS/MS data were processed by LEDA algorithm which allowed to assign a relative abundance in the reference ion signal to each isomer present. Quantitative results showed no significant differences between the two chromatographic systems proposed, proving that the use of LEDA algorithm allowed the distinction of the six isomers in a quarter of the time.

AGS Gastric Cells: Antioxidant Activity and Metabolic Effects of Phenolic Extracts from Different Monocultivar Virgin Olive Oils.

The effects of the phenolic compounds of extra virgin olive oil (EVOO) on AGS cells have never been studied so far, which is the aim of this study. The profiles of the main phenolic components in EVOOs, mainly secoiridoid compounds derived from the transformation of oleuropein during the olive milling process, were evaluated and compared. Oils of different origins were evaluated aiming at verifying whether chemical differences in the phenolic composition of the dry extracts played a role in the metabolism and in maintaining the cellular redox state of AGS cells. The following key enzymes of some metabolic pathways were studied: lactate dehydrogenase, enolase, pyruvate kinase, glucose 6-phosphate dehydrogenase, citrate synthase, 3-Hydroxyacyl-CoA dehydrogenase and hexokinase. As confirmed through PCA analysis, pretreatments with the dry extracts of EVOOs at different concentrations appeared to be able to counteract the enzymatic activity alterations due to oxidative stress induced by H2O2 1 mM and 2 mM. The studied phytocomplexes showed the ability to protect AGS cells from oxidative damage and the secoiridoid derivatives from both oleuropein and ligstroside contributed to the observed effects. The results suggested that EVOOs with medium to high concentrations of phenols can exert this protection.

Millet Fermented by Different Combinations of Yeasts and Lactobacilli: Effects on Phenolic Composition, Starch, Mineral Content and Prebiotic Activity.

Millet is the sixth-highest yielding grain in the world and a staple crop for millions of people. Fermentation was applied in this study to improve the nutritional properties of pearl millet. Three microorganism combinations were tested: Saccharomyces boulardii (FPM1), Saccharomyces cerevisiae plus Campanilactobacillus paralimentarius (FPM2) and Hanseniaspora uvarum plus Fructilactobacillus sanfranciscensis (FPM3). All the fermentation processes led to an increase in minerals. An increase was observed for calcium: 254 ppm in FPM1, 282 ppm in FPM2 and 156 ppm in the unfermented sample. Iron increased in FPM2 and FPM3 (approx. 100 ppm) with respect the unfermented sample (71 ppm). FPM2 and FPM3 resulted in richer total phenols (up to 2.74 mg/g) compared to the unfermented sample (2.24 mg/g). Depending on the microorganisms, it was possible to obtain different oligopeptides with a mass cut off ≤10 kDalton that was not detected in the unfermented sample. FPM2 showed the highest resistant starch content (9.83 g/100 g) and a prebiotic activity on Bifidobacterium breve B632, showing a significant growth at 48 h and 72 h compared to glucose (p < 0.05). Millet fermented with Saccharomyces cerevisiae plus Campanilactobacillus paralimentarius can be proposed as a new food with improved nutritional properties to increase the quality of the diet of people who already use millet as a staple food.

Composition of discarded Sicilian fruits of Opuntia ficus indica L.: Phenolic content, mineral profile and antioxidant activity in peel, seeds and whole fruit.

Sicily (Italy) is the second producer of Opuntia ficus-indica (OFI) fruits after Mexico. To date, huge quantities of fruit are discarded during the selection for the fresh market, generating a large amount of by-product to be valorized. This study aimed to investigate on the composition of OFI discarded fruits from the main Sicilian productive areas, over two harvesting periods. Peel, seeds and whole fruit samples were characterized in terms of minerals and phenolic compounds through ICP-OES and HPLC-DAD-MS. Potassium, calcium and magnesium were the most abundant elements and peel samples showed the highest values. Seventeen phenolic compounds were detected in peel and whole fruit, including flavonoids, phenylpyruvic and hydroxycinnamic acids, while only phenolic acids were found in the seeds. A multivariate chemometric approach highlighted a correlation between the mineral and phenolic content and the different parts of the fruit as well as a significant influence of productive area.

Acmella oleracea (L.) R.K. Jansen: Alkylamides and phenolic compounds in aerial parts and roots of in vitro seedlings.

Acmella oleracea L. is an edible and medicinal plant commonly known for its local anaesthetic effect induced by the alkylamide spilanthol. It is also rich of secondary metabolites of biological interest, mainly phenolic acids and glycosylated flavonoids. This study evaluated for the first time alkylamides and phenolic compounds in aerial parts and roots of seedlings grown in vitro and produced from single seed and from regenerating lines. The extracts obtained showed similar chemical profiles and the caffeic acid derivatives were the most abundant phenolic compounds. Spilanthol was prevalent in the aerial parts, especially in samples of seedlings obtained from regenerating lines, in which reached maximum value of 1.72 mg/g dried matter (DM). The roots contained a lower content of alkylamides, while showing twice as much total phenols (11.19 mg/g DM) as the aerial parts. A hexane fractionation step allowed to recover spilanthol and its derivatives in a concentrated extract, which reached a value of 63.4 mg/g dried extract in the aerial parts from seedlings from regenerating lines. Hydroalcoholic dried extracts showed high yields (30-45 % on dried matter) and those obtained from aerial parts contained up to 5.69 mg/g of spilanthol.

Phenolic compounds and polysaccharides in the date fruit (Phoenix dactylifera L.): Comparative study on five widely consumed Arabian varieties.

The study analysed polysaccharides and phenolic compounds in widely consumed but little studied date fruits varieties such as Sukkari, Ajwa, Segae, Barrny and Khalas harvested at Tamr stage. The total phenols were in similar amount in the five varieties and ranged from 20 to 50 mg/100 g DW. The decoction and successive centrifugation made it possible to collect two main polysaccharide fractions for all the selected fruits. For each variety the first fraction was more abundant, with a lower swelling capacity and a higher amount of galacturonic acid (28.3% to 40.1%). The second fraction was only soluble in alkaline solution, with an average galacturonic acid content of only 17%. The different structure of the two polysaccharide fractions was also confirmed by the composition in neutral sugars and the degrees of methylation and acetylation. The proposed extraction procedure could be applied for larger scale extraction of the date fruit polysaccharides.

Steryl ferulates composition in twenty-two millet samples: Do "microwave popping" and fermentation affect their content?

Climate change has led to rediscovery of minor drought tolerant grains such as millet. Among its bioactive molecules, steryl ferulates have been poorly explored. Steryl ferulates composition of was investigated by high performance liquid chromatography-diode array detector-tandem mass spectrometry and high resolution tandem mass spectrometry in twenty-two millet samples and also in some fermented and microwave heated samples. Six compounds were found in Panicum, Pennisetum, Eleusine and Setaria genera, with a prevalence of campestanyl and sitostanyl ferulate. The lowest steryl ferulates content was found in Panicum, with values ranging from 2.98 ± 0.04 µg/g to 8.72 ± 0.41 µg/g. Foxtail millet and finger millet showed the highest amount with 46.07 ± 5.20 µg/g and 85.29 ± 4.30 µg/g, respectively. As for pearl millet, microwave heating and fermentation increased steryl ferulates by two (33.77 ± 0.88 µg/g) and five (75.83 ± 1.25 µg/g) times, with respect to the untreated sample. Microwave heating and fermentation could be used to increase steryl ferulates in millet.