Chemical Characterization of Different Products from the Tunisian Opuntia ficus-indica (L.) Mill.

Various dried (by-)products from the Tunisian O. ficus-indica were elucidated for their proximate composition, fatty acid (FA) composition, inorganic elements, sugars, and polyphenols. Nopal and prickly pear peel and seeds were abundant in fiber (respectively, 28.39, 12.54, and 16.28%). Seeds had also high protein (17.34%) and may be source of an edible oil, due to lipids (9.65%) poor in saturated FAs (14.12%) and rich in linoleic acid (61.11%). Nopal and peel showed the highest levels of Mg (493.57 and 345.19 mg/100 g), K (6949.57 and 1820.83 mg/100 g), Mn (59.73 and 46.86 mg/Kg) and Fe (23.15 and 15.23 mg/Kg), while the fruit pulp predominantly constituted of sugars, glucose and arabinose being predominant (42.57 and 13.56 g/100 g). Total polyphenols widely varied among the Opuntia products (108.36–4785.36 mg GAE/100 g), being mainly represented by hydroxycinnamic and hydroxybenzoic acids, and flavonoids as well. In particular, peel may be revalorized for these valuable bioactives, including 4-hydroxybenzoic acid (484.95 mg/100 g), cinnamic acid (318.95 mg/100 g), rutin (818.94 mg/100 g), quercetin (605.28 mg/100 g), and several isorhamnetin and kaempferol glycosides. Overall, the Tunisian prickly pear cactus could encourage a sustainable production, an effective waste management, and may provide several benefits for human health, in accordance with the model of the Mediterranean diet.

The Effect of Thermal Treatment on Selected Properties and Content of Biologically Active Compounds in Potato Crisps

The aim of this study was to determine the effect of blanching and frying on selected properties of potato crisps of yellow- and purple-fleshed cultivars. The material used was yellow flesh cv. Ismena and purple flesh cv. Provita. Potato slices were blanched (1–5 min at 80–90 °C) and then fried (155–175 °C). The control sample was comprised of crisps that were not blanched. The fat content and color parameters were determined in crisps, while in defatted samples, the following were determined: the content of total polyphenols; antioxidant capacity, measured by the ability to scavenge the ABTS•+ radical cations (TEAC ABTS) and by the FRAP method; and the level of fluorescent intermediary compounds (FICs) and browning index (BI), as indicators of the progress of the Maillard reaction. The content of kynurenic acid (KYNA) was examined in the raw material, in slices, in the water after blanching and in the crisps. Blanching affected the fat absorption, with time being more critical than temperature. The color of crisps from yellow flesh potatoes after blanching lightened, while the color in the purple samples darkened. The content of total polyphenols was higher in purple crisps. Increasing the temperature and shortening the time of blanching increased the polyphenol content and the antioxidant capacity. Blanching decreased the level of FICs, while frying increased FICs. Higher BI values characterized the crisps from cv. Provita. Blanching reduced BI values by 50%, while frying at highest temperature increased these values. The content of KYNA in purple potatoes was almost three times higher than in yellow ones. Blanching and frying decreased the KYNA content in potatoes and fried crisps.

Physicochemical and sensorial characterization of yacon mixed juice with bioactive properties

ABSTRACT: This study developed a palatable, acceptable, and functional mixed juice of pineapple (Ananas comosus var. Comosus), passion fruit (Passiflora edulis flavicarpa degener), and yacon (Smallanthus sonchifolius), with enhanced bioactive and prebiotic compounds. The ideal proportion of fruit and yacon was derived after planning a mixture with six formulations and by evaluating their bioactive compounds and organic acid profile. The best formulation sensory evaluation was performed by the Just-About-Right test (JAR) and global acceptance. The chosen mixed juice (M6 - 30% pineapple, 45% passion fruit, and 30% yacon) presented results that showed elevated levels of antioxidant activity (82.5% DPPH* inhibition), carotenoids (0.97 mg.100g-1), and total polyphenols (70.28 mg.100g-1). Total flavonols (23.95 mg.100g-1), total anthocyanins (1.37 mg.100g-1), gallic acid (3.13 μg.mL-1), quercetin (2.25 μg.mL-1), syringic acid (1.01 μg.mL-1), citric acid (949.30 mg.100g-1), malic acid (140.35 mg.100g-1), and 0.58% of dietary fiber were also reported. Sensorially, consumers perceived high acidity, strong flavor, and a fibrous texture, which might have affected the global acceptance of the juice (6.0). Results indicated the feasibility of obtaining a functional and palatable mixed juice using yacon.

Treatment of Winery Wastewater with a Combination of Adsorption and Thermocatalytic Processes

The release of winery wastewater (WW) into the environment, without proper treatment, can cause severe problems to freshwater quality and natural fauna and flora. Therefore, in this work a treatment process was studied, combining adsorption and thermocatalytic oxidation processes. In a more specific way, it optimized the combination of activated sodium bentonite (Na-Mt) and potassium persulfate (KPS)/sodium percarbonate (SPC) as oxidant agents. With the combination of best operational conditions of adsorption ([Na-Mt] = 5.0 g/L, pH = 3.0, V = 500 mL, agitation 350 rpm, T = 298 K, t = 24 h) and thermocatalytic oxidation processes (/H2O2 ratio = 1:0.25, /H2O2 dosage = 0.1:0.025 (g/g), pH = 7.0, T = 343 K, agitation 350 rpm, t = 2 h), a total organic carbon, chemical oxygen demand and total polyphenols removal of 76.7, 81.4 and >99% was achieved, respectively. Finally, it was evaluated the effect of the treatment processes in the germination index (GI) of different plant seeds. A GI > 80% was achieved, showing a low phytotoxicity effect of the processes applied in the winery wastewater treatment.

Antioxidant Capacity and Nutritional Value of Potato Tubers (Solanum tuberosum L.) as a Dependence of Growing Conditions and Long-Term Storage

The aim of the study was to assess the interactive effect of the use of bio-fertilizer and organic matter brought into the soil, as well as to limit the use of mineral fertilization on the content of bioactive compounds in potato tubers cultivar ‘Satina’. The test results show a positive effect of the applied bio-fertilizer in all tested variants of organic fertilization (straw, fodder pea, manure) on the level of the tested compounds. Comparing the content of crude protein in tubers from plots where half the dose of mineral fertilization was applied, the use of bio-fertilizer increased the content of this component, especially after using straw. After 6 months of storage, organic fertilization had no significant effect on the protein content, while significant differences were found in tubers fertilized with mineral, in favor of the full dose of NPK fertilizers. The storage time increased the content of tyrosine, leucine, lysine, alanine, glutamic acid, and total AA, and also methionine, aspartic acid, and asparagine, while the content of isoleucine and phenyl-alanine decreased. The highest content of total polyphenols was found in tubers where the plots were covered with pea application, a full dose of mineral fertilizer, and the use of bio-fertilizer. Unfortunately, after 6 months of storage, potato tubers from plots fertilized with peas, especially those fertilized with half the dose of mineral fertilization and without the use of biofertilizer, significantly lost the most total polyphenols. Similar relationships were obtained for the level of chlorogenic acid in tubers, which is significantly correlated with the content of polyphenols, but only organic fertilization in the form of peas significantly increased the concentration of chlorogenic acid. On the other hand, the highest post-harvest antioxidant activity was characteristic of tubers from plots fertilized with manure, with a full dose of mineral fertilization and biofertilizer. During the 6-month storage, there was a decrease in the antioxidant capacity, on average 12.4% for the objects. This may indicate the influence of polyphenolic compounds as well as other antioxidants on the assessed trait.

Cryoconcentration by Centrifugation–Filtration: A Simultaneous, Efficient and Innovative Method to Increase Thermosensitive Bioactive Compounds of Aqueous Maqui (Aristotelia chilensis (Mol.) Stuntz) Extract

Maqui (Aristotelia chilensis (Mol.) Stuntz) is a Chilean berry rich in antioxidants, which are mostly found in the pulp and skin of the fruit. The objective was to evaluate the cryoconcentration process by centrifugation–filtration as a simultaneous, efficient, and innovative method to increase the content of thermosensitive bioactive compounds of aqueous maqui extract. Cryoconcentration separated the concentrated solute from the aqueous maqui extract with an efficiency of more than 95%; it increased the content of total polyphenols and total anthocyanins and antioxidant capacity by 280%, 573%, and 226%, respectively. Although the concentrates obtained by evaporation at 50, 70, and 80 °C increased the content of bioactive compounds, they did so in a lower percentage than the cryoconcentrate. Furthermore, cyanidin 3,5-diglucoside was degraded at 70 and 80 °C. In conclusion, cryoconcentration by centrifugation–filtration as a simultaneous process efficiently separates the solutes from the frozen matrix of aqueous maqui extract, and it maintains and increases the contents of polyphenols and anthocyanins and antioxidant capacity. This method is recommended for concentrating natural berry extracts with thermosensitive compounds.

Determination of the quantitative content of some groups of phenolic compounds in tinctures from the raw material of plant families Polygonaceae, Rosaceae, Asteraceae

Aim. To determine the quantitative content of total polyphenols and the amount of hydroxycinnamic acids in the series of tinctures from rhizomes with roots of Rumex confertus Willd., Sanguisorba officinalis L., roots of Rosa majalis Herrm., Rosa canina L., Arctium lappa L., Arctium minus (Hill) Bernh., Arctium tomentosum Mill., and the herb of Bidens tripartita L.Materials and methods. As study objects the tinctures from rhizomes with roots of Rumex confertus, Sanguisorba officinalis, roots of Rosa majalis, Rosa canina, Arctium lappa, Arctium minus, Arctium tomentosum and the herb of Bidens tripartita were used. These tinctures were obtained by the method of maceration at room temperature and the ratio of 1 : 5 of the plant raw material/finished products; the extractant was 50 % ethyl alcohol. The quantitative content of total polyphenols and the amount of hydroxycinnamic acids was determined by spectrophotometry according to the methods of the State Pharmacopoeia of Ukraine.Results and discussion. The limits of the quantitative content of total polyphenols and the amount of hydroxycinnamic acids in the tinctures were determined. They were not less than 0.070 mg mL-1 and 0.002 mg mL-1 for the tincture of rhizomes with roots of Rumex confertus, 0.100 mg mL-1 and 0.005 mg mL-1 for the tincture of rhizomes with roots of Sanguisorba officinalis, 0.070 mg mL-1 and 0.002 mg mL-1 for the tincture of Rosa majalis roots, 0.080 mg mL-1 and 0.001 mg mL-1 for the tincture of Rosa canina roots, 0.01 mg mL-1 and 0.001 mg mL-1 for the tincture of Arctium lappa roots, 0.010 mg mL-1 and 0.002 mg mL-1 for the tincture of Arctium minus roots, 0.001 mg mL-1 and 0.002 mg mL-1 for the tincture of Arctium tomentosum roots, 0.070 mg mL-1 and 0.001 mg mL-1 for the tincture of Bidens tripartita herb, respectively.Conclusions. The quantitative content of total polyphenols and the amount of hydroxycinnamic acids in tinctures from rhizomes with roots of Rumex confertus, Sanguisorba officinalis, roots of Rosa majalis, Rosa canina, Arctium lappa, Arctium minus, Arctium tomentosum and the herb of Bidens tripartita have been determined. The data obtained will be used in further work on the study of tinctures of these types of the plant raw material.

EFFECT OF BIOSTIMULANTS ON SOME BIOACTIVE COMPOUNDS AND NITRATE LEVEL IN LETTUCE (Lactuca sativa L.) GROWN UNDER UNHEATED PLASTIC TUNNEL

Based on the regulation (EU) No 2015/1107 in 8 July 2015, Willow (Salix alba) bark extract is a recent approved basic substance in Europe as a safe and effective environmentally friendly fungicide to be used in plant protection. Because of having indole butyric acid content, it is also used as a growth hormone to promote rooting in cutting propagation of wooden part in horticultural plants. This research aimed to evaluate the effect of willow extract and Ferbanat L (Bistep) on lettuce leaves. Bistep is an organic solution of nano fertilizer which is produced in Hungary and allowed as „Bistep plant conditioner”. Furthermore, the experiment evaluated their interaction on some bioactive compounds in different lettuce varieties, too. Three different lettuce varieties (King of May, Kobak and Great Lakes) were evaluated for total polyphenols, vitamin C and nitrate content in fresh leaves. The results indicate that the contents were significantly affected by the used biostimulants rather than varieties. Significantly difference of the total polyphenols was recorded in the plants treated with Willow + Bistep (80.64 mg GAE / 100g) in comparison to the control (55.85 mg GAE / 100g) in the mean of varieties. Similar result was recorded for the vitamin C. However, plants treated with Willow extract resulted in the highest level of nitrate content (692.00 mg/100g), while the lowest amount was measured in the control (488.00 mg/100g). According to our results, Willow bark extract can be a beneficial source of natural growth regulator or fungicide; however, when it is used alone for vegetables, the nutrient content (mainly nitrate level) must be checked before consuming and delivering to the market.