Iridoids and anthocyanins in cornelian cherry (Cornus mas L.) cultivars

The qualitative and quantitative characteristics of iridoids and anthocyanins of cornelian cherry (Cornus mas L.) ripe fruits were investigated. The characteristics of these compounds were determined using HPLC-DAD, LC–ESI-MS, and NMR methods. Two iridoids (loganic acid and cornuside) and five anthocyanins (delphinidin, cyanidin, and pelargonidin glycosides) were identified in cornelian cherry fruits. The MS fragmentation pathways of the two iridoids were studied. A total of 26 different cultivars and 2 ecotypes, harvested from five locations in the years 2007–2011 were analyzed. The content of total iridoids in cornelian cherry fruits covered a wide range, i.e. from 86.91 to 493.69 mg/100 g fw. Loganic acid was the most dominant iridoid compound identified in cornelian cherry fruits and amounted to 88–96% of total iridoids. The total content of anthocyanins in red cultivars of cornelian cherry fruits was in a wide range from 5.59 to 134.57 and 341.18 mg/100 g fw. In most cornelian cherry fruits, pelargonidin 3-galactopyranoside was dominant.     

Phenolic acids,flavonols and anthocyanins in Corema album (L.) D. Don berries

Phenolic compounds of Corema album (Ericaceae) wild edible berries were determined by LC–DAD–MS/MS. Fifteen compounds were identified and quantified, including phenolic acids (2268.1 ± 229.2 mg/kg of dried weight, DW) such as chlorogenic and neochlorogenic acids, flavonols (638.3 ± 80.1 mg/kg DW) including quercetin 3-O-hexoside and rutin, and the anthocyanins (19. 6 ± 2.4 mg/kg DW) cyanidin 3-O-glucoside, cyanidin 3-O-pentoside and delphinidin 3-O-hexoside. Phenolic acids, the main phenolic compounds in this fruit, were fractionated into their free and bound forms, and analysed by GC–MS after hydrolysis. Eleven compounds (benzoic, salicylic, t-cinnamic, p-hydroxybenzoic, vanillic, gentisic, syringic, p-coumaric, gallic, ferulic and caffeic acids) were identified on the basis of GC retention times and simultaneously recorded mass spectra, namely caffeic, benzoic, ferulic and vanillic acids as the major phenolic acids in Corema album berries.     

Identification and quantification of flavonoids in traditional cultivars of red and white onions at harvest

Onions are rich in different types of phenolics, mainly flavonols, and in red varieties anthocyanins are also present. This is significant because these classes of phenolics are antioxidants and hence may impart important functional properties to onions. The aim of the present work was to simultaneously determine flavonol and anthocyanin concentrations in different onion varieties, two white (Branca da Póvoa and the hybrid SK409) and three red (landrace Vermelha da Póvoa, a selected line of Vermelha da Póvoa and Red Creole). Flavonols (quercetin 7,4-diglucoside, quercetin 3,4-diglucoside, isorhamnetin 3,4-diglucoside, quercetin 3-glucoside, quercetin 4-glucoside and isorhamnetin 4-glucoside) were the predominant polyphenolic compounds. White cultivars had the lowest total flavonol content, with values of 89.3 ± 38.5 and 101.0 ± 18.9 mg quercetin/kg fresh weight for Branca da Póvoa and the hybrid SK409, respectively. The red onions had the highest levels of flavonols, especially the selected population of Vermelha da Póvoa and Red Creole, with values of 280.2 ± 41.5 and 304.3 ± 81.2 mg quercetin/kg fresh weight, respectively. Red onions are not only richer in flavonols, but also contain anthocyanins. Four anthocyanins (cyanidin 3-glucoside, cyanidin 3-laminaribioside, cyanidin 3-(6″-malonylglucoside), and cyanidin 3-malonylaminaribioside) were quantified in all red onions, with Red Creole presenting the highest concentration (28.6 ± 8 mg cyanidin/kg fresh weight). Red onions may be recommended for their major potential functional properties. A distinct gradient in total flavonoid content was found between the outer, central and inner edible scales and along the longitudinal axis of the bulb. Differences in flavonol levels between small- and large-sized onions were also found. All of these factors are of paramount importance for sampling and characterizing onions with regard to flavonoids.     

Variations in the carotenoid and anthocyanin contents of Korean cultural varieties and home-processed sweet potatoes

The sweet potato is an important industrial crop and a source of food that contains useful dietary fiber and vitamins. Recently, orange- and purple-fleshed varieties have come under the spotlight due to their healthful components, carotenoids and anthocyanins, respectively. In this study, an HPLC-DAD method was applied to determine the carotenoid composition and content in nine Korean cultural varieties of sweet potato. Changes in carotenoid contents and composition were also observed during home-processing of an orange-fleshed cultivar with high carotenoid content (530 ± 60 μg/g of dry weight, DW as all-trans-β-carotene). A loss of the carotenoids was observed for all of the home-processing methods examined; the baked or boiled or steamed sweet potatoes had higher amounts of all-trans-β-carotene (246 ± 34, 253 ± 29 and 240 ± 21 μg/g DW, respectively) than pressure-cooked, sautéed and fried ones (194 ± 21, 201 ± 28 and 111 ± 19 μg/g DW, respectively). Interestingly, cis-isomer of the all-trans-β-carotene, 13Z-β-carotene was found in elevated amounts in all of the processed samples, particularly in baked, pressure-cooked and steamed sweet potatoes compared to control. Variations in anthocyanin content in the nine cultural varieties and home-processed sweet potatoes were also determined by an HPLC-DAD method.     

Cold storage of blueberry (Vaccinium spp.) fruits and juice: Anthocyanin stability and antioxidant activity

Blueberries (Vaccinium spp.) may be considered one of the best potential sources of antioxidants in the diet. This characteristic results from the presence of flavonoids (especially anthocyanins), tannins and phenolic acids in the fruits. The objective of this work was to analyze the anthocyanin stability and antioxidant activity of refrigerated whole blueberry juice stored at 4 °C for 10 d, and of fruits stored frozen (−18 °C) for 6 months, in order to determine the changes occurring during storage. The frozen fruits showed a significant increase (p < 0.05) in antioxidant activity during the 3rd month of frozen storage, followed by a decrease up to the end of the 6-month period. The juice was analyzed every other day, and the antioxidant activity changed on the 8th d of refrigerated storage, remaining stable up to the 10th d. There were significant losses of anthocyanins both in the frozen fruits (59%) and refrigerated juice (83%). The antioxidant capacity was shown to be stable during cold storage both in the case of the fruits and whole juice, whereas the anthocyanins were degraded, possibly due to oxidations and/or condensation reactions with other phenolic compounds. More studies are required to optimize the storage time and temperature of these products with respect to nutrient stability.     

Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits

The present study sought to determine the nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits from different districts in Malaysia, namely Kanowit, Sarikei, Kapit and Song in Sarawak. Two varieties of the fruits were investigated. Lipid (21.16 ± 4.71 to 25.76 ± 3.03 g/100 g FW) was the major macronutrient in dabai fruits, while the predominant minerals were calcium, sodium and potassium. The fruit protein was rich in aspartic and glutamic acids which accounted for 45–49% of total amino acids. Purple dabai fruits from Kapit were found to contain the highest total phenolic levels, flavonoids and anthocyanin contents (p < 0.01) and to exhibit the most significant antioxidant activities (p < 0.01), using trolox equivalent antioxidant capacity (TEAC) and ferric reducing ability (FRAP) assays. Antioxidant activities were highly correlated with total phenolic and flavonoid contents of dabai fruits.     

Determination of anthocyanins from black carrots by UHPLC-PDA after ultrasound-assisted extraction

Anthocyanins from black carrots (Daucus carota ssp. sativus var. atrorubens Alef.) are widely applied to impart bright red hues to foods such as beverages, fruit preparations, and confectionary. Highly efficient methods for their analyses may be instrumental for manufacturers of coloring foodstuff and for plant breeders to select highly pigmented black carrot varieties. For this purpose, a rapid and exhaustive ultrasound-assisted extraction procedure for anthocyanins was developed and validated. Thereby, deteriorative enzymes like polyphenol oxidase and peroxidase were inactivated. Extraction required only 60 s, yielding coefficients of variation (CVs) for intra-day and inter-day repeatability of ≤4.4 and 4.7%, respectively. For post-extractive quantitation of black carrot anthocyanins, a rapid UHPLC-PDA method was developed and validated. Compared to HPLC separation on a core-shell-column, UHPLC separation time (4.5 min) was 8.2 times faster and solvent consumption 92% less. Limits of detection and quantitation were fully satisfactory. Moreover, stability of non-acylated pigments used as reference compounds was acceptable for 24 h at room temperature, and within 4.5 months of storage time at −20 °C and −80 °C, pigment concentration remained unchanged. Two black carrot varieties were analyzed applying the proposed method, and the results were compared to previously published data.     

Phenolic compounds and antioxidant activity of Spanish commercial grape juices

Evaluation of the antioxidant activity of components of the diet is important in order to establish healthy consumption patterns. Data are reported here on the antioxidant activity (FRAP and ABTS), of 20 commercial grape juices and 10 typical Spanish wines and on their content of total phenolic compounds, anthocyanins, flavonoids and 10 individual phenolic compounds (flavanols, benzoic acids and cinnamic acids, measured by HPLC-UV). Red grape juices had a significantly higher (p < 0.05) concentration of total phenols (1177 vs. 744 mg gallic acid/L), flavonoids (98 vs. 63 mg catechin/L) and a higher antioxidant activity (9.16 vs. 2.83 meq Trolox/L) in comparison to white grape juices. In comparison to the white wines, white grape juices contained more total phenols (744 vs. 286 mg gallic acid/L) and flavonoids (63 vs. 29 mg catechin/L) and evidenced higher antioxidant activity (p < 0.05). In comparison to the red wines, a lower content of total phenols (286 vs. 2358 mg gallic acid/L) and flavonoids (228 vs. 29 mg catechin/L) and an absence of anthocyanins were observed in the white wines, which are therefore less antioxidant. Although a two-fold higher concentration of antioxidant compounds was found in red wines than in red grape juices, the latter may be a good option for all age groups because of the absence of alcohol and the potentially beneficial health effects of their phenolic composition and elevated antioxidant activity.     

The study of antioxidant capacity of varieties of nalewka,a traditional Polish fruit liqueur,using EPR,NMR and UV–vis spectroscopy

The antioxidant properties of various kinds of the traditional Polish alcoholic beverage nalewka were investigated using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and ultraviolet–visible (UV–vis) spectroscopy. The antioxidant capacity was measured by EPR spectroscopy in μmol Trolox (TE) in a 100 mL nalewka sample. The total phenolic content was measured by Folin–Ciocalteu (FC) assays while aromatic proton content (H_ar) was determined by NMR spectroscopy; subsequently the correlation among these values was explored. All of the investigated nalewkas exhibited antioxidant properties. The values of Trolox equivalent antioxidant capacity (TEAC_DPPH) were in the range 45–1045 μmol TE/100 mL. It was found that the value of the TEAC_DPPH corresponded to the TP (r = 0.96) and H_ar (r = 0.95). Moreover, the TEAC_DPPH values depended on the kinds of fruits used for nalewkas’ preparation.     

Identification and quantification of phenolic compounds responsible for the antioxidant activity of sweet potatoes with different flesh colours using high performance thin layer chromatography (HPTLC)

The objectives of the present study were to develop a simple high performance thin layer chromatography (HPTLC)-based protocol: (i) to allow high-throughput profiling of phenolic compounds of microwaved roots from 295 sweet potato varieties and breeding lines, (ii) to quantify the content of anthocyanins and caffeoylquinic acid (CQA) derivatives, and (iii) to determine their respective contributions to the antioxidant activity of sweet potato methanolic extracts using the DPPH test. Analysed accessions were separated into three groups: white-fleshed (n = 100), orange-fleshed (n = 64) and purple-fleshed (n = 131). Purple-fleshed accessions presented the highest mean CQA content. After DPPH treatment and transmittance scanning of the plate at 517 nm, the most active free radical scavengers were found to be the four CQAs (CGA, 3,4-, 4,5- and 3,5-diCQA) while the anthocyanins were found to be less active. The total antioxidant capacity of the sweet potato methanolic extracts was mostly linked to total CQAs content. This method can now be used for fast routine analysis and selection of sweet potato breeding clones.     

Assessment of hydroxymethylfurfural and furfural in commercial bakery products

A survey was conducted on the presence of hydroxymethylfurfural (HMF) and furfural in bread and bakery products; for this purpose a reliable extraction procedure followed by high performance liquid chromatography (HPLC) was applied. The performance of the method was evaluated in terms of linearity (r always > 0.99); detection limits (0.001 mg L⁻¹ for furfural and 0.006 mg L⁻¹ for HMF); recovery percentages (98.5–100.5% for HMF and 94.9–98.9% for furfural); intraday precision (<4.65%) and interday precision (<7.51%). Two batches of a wide variety of products commercially available were analysed (a total of 88 samples). HMF and furfural levels presented high variability between products and batches of the same product. Cake/pastry samples showed the lowest HMF content (3.0 mg kg⁻¹ fw) while biscuits showed the highest content (7.8 mg kg⁻¹ fw) (p < 0.05). Regarding furfural, bread samples presented the highest furfural content (5.3 mg kg⁻¹ fw) (p < 0.05), cake/pastry and biscuits showed the lowest content (1.9 and 3.0 mg kg⁻¹ fw, respectively). Chocolate containing samples presented higher amounts of furfural (>20 mg kg⁻¹). These results indicate that special attention should be given to furfural content of bread (due to its daily high consumption) and re-evaluation of dietary exposure.     

Anthocyanins from the fruits of Rubus croceacanthus and Rubus sieboldii,wild berry plants from Okinawa,Japan

Anthocyanins from the fruits of Rubus croceacanthus and Rubus sieboldii, wild berries from Okinawa, Japan, were extracted using 80% methanol containing 0.5% acetic acid, and the extracts were separated by a DIAION HP-20 column. The major anthocyanins were purified by preparative HPLC and their structures were determined by NMR and MS spectrometry. Cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside were identified from R. croceacanthus, and their contents were 81.44 ± 1.01 mg and 170.02 ± 4.36 mg/100 g fresh weight, respectively. Pelargonidin-3-O-glucoside and pelargonidin-3-O-rutinoside were identified from R. sieboldii, and their contents were 10.04 ± 0.34 mg and 15.08 ± 0.48 mg/100 g fresh weight, respectively. An ORAC assay indicated that the two Okinawan wild berries, especially R. croceacanthus, had potent antioxidant activity compared to raspberry (Rubus idaeus).     

The effect of frying on anthocyanin stability and antioxidant activity of crisps from red- and purple-fleshed potatoes (Solanum tuberosum L.)

Red- and purple-fleshed potatoes (Solanum tuberosum L.) are a good source of polyphenols, mainly anthocyanins as one of the most important components. The chemical composition with reducing sugars and the total polyphenol contents were analyzed in four purple potato varieties (Salad Blue, Vitelotte, Valfi, Blue Congo) and three red-fleshed potato varieties (Rosalinde, Herbie 26, Highland Burgundy Red). The anthocyanin composition of raw potato and potato crisps was characterized by high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) method. Moreover, the antioxidant activity was measured with the radical scavenging assays using 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as well as ferric reducing ability of plasma assay (FRAP). In addition, colour parameters in prepared potato crisps were evaluated. Both red and purple-fleshed potato varieties contained high levels of total polyphenols (227–845 mg 100 g⁻¹ dry weight) and anthocyanins (21–109 mg 100 g⁻¹ dry weight). The process of frying caused degradation of anthocyanin compounds (38–70%). The HPLC–MS/MS analysis showed that pelargonidin and malvidin derivates were more stable during frying than petunidin derivatives. Although frying process affected the anthocyanin and polyphenol levels, obtained potato crisps exhibited bright intensive colour and good antioxidant activity.     

Nutritional value of tomatoes (Solanum lycopersicum L.) grown in greenhouse by different agronomic techniques

The relevance of agronomic practices on the nutritional quality greenhouse-grown tomatoes has been recognized. We investigated the influence of (1) cultivar: two local (Pera-Girona and Montserrat) and one commercial (Caramba) varieties; (2) nitrogen dose in nutrient solution (low vs. standard N dose); (3) treatment for plant disease control (sulfur vs. Milsana^®) and (4) ripeness (orange vs. full-red color) on levels of carotenoids, phenolic compounds, ascorbic acid and minerals of fruits. Carotenoids and ascorbate were mainly influenced by variety and ripening stage, while N dose slightly affected minerals in fruits; treatments against plant diseases exerted only negligible effects on measured compounds. Local tomato varieties appear more promising as food source of carotenoids, mainly lycopene, and of hydroxycinnamates, such as 5-caffeoylquinic acid and caffeoylquinic derivatives, than commercial variety (total carotenoids: 67.43 mg kg⁻¹ fw vs. 56.34 mg kg⁻¹ fw of Pera-Girona vs. Caramba and total hydroxycinnamates: 90.87 mg kg⁻¹ fw vs. 37.90 mg kg⁻¹ fw of Montserrat vs. Caramba, at full-red color). Tomato variety and harvest maturity of fruit were the main factors affecting nutritional value of tomatoes, while Milsana^® treatment did not result in evident nutritional benefits. However, the use of this elicitor might be appropriate considering the increasing environmentally friendly attitudes of consumers.     

Chemical composition,antioxidant activities and total phenolic content of Arbutus andrachne L. (Fam. Ericaceae) (the Greek strawberry tree) fruits from Turkey

Arbutus andrachne L. and A. unedo L. are two members of the Ericaceae family. The species are distributed in coastal parts of Anatolia and have edible fruits. We determined several characteristics of eight A. andrachne accessions collected from different parts of the Mediterranean regions of Anatolia. A. unedo is also represented with a sample. Notable differences were found among A. andrachne accessions. On average, the fruit width and length were 12.3 and 10.8 mm, respectively. All of the element concentrations that were tested varied considerably. The average of the total organic acids was 0.47 g/100 g fruit. Among the organic acids measured, malic acid had the highest content (0.34 g/100 g fruit) followed by ascorbic (0.10 g/100 g fruit) and citric acids (0.03 g/100 g fruit). The average for total sugars of the A. andrachne accessions was 16.38 g/100 g fruit. Fructose was the main sugar (average of 9.75 g/100 g fruit) followed by glucose (5.33 g/100 g fruit) and sucrose (1.19 g/100 g fruit). Among the A. andrachne accessions tested, the total phenolics ranged from 2422 to 4102 μg gallic acid/g fresh weight (fw) with an average of 3343 μg gallic acid equiv. g/fw. Antioxidant activities, determined by TEAC (Trolox equivalent antioxidant capacity) and FRAP (Ferric reducing ability of plasma), reached up to 36.1 and 29.5 μmol Trolox equiv. (TE) g/fresh weight, respectively. It can thus be concluded that A. andrachne is a good source of phenols and antioxidants.     

The content of selected minerals and vitamin C for potatoes (Solanum tuberosum L.) from the high Tiber Valley area,southeast Tuscany

Potatoes (Solanum tuberosum L.) from the high Tiber valley area (TVA; Tuscany, Italy), have been sampled and analyzed for selected mineral content (Na, Mg, K, Ca, and Mn, Fe, Cu and Zn) and vitamin C, the year 2012; some samples from 2011 and 2013 crops were also collected and analyzed. The varieties were Daytona (DAY), Kennebec (KEN), Sifra (SIF) and Volare (VOL). Control samples consisted of mixed commercial varieties from the local market, namely C1, C2 and C3. The low content of sodium, especially for KEN (46 ± 3 mg/kg FD (freeze dry), year 2012) and SIF (47 ± 3) (VOL (55 ± 3) and DAY (61 ± 3) have a little higher values) is worth of note and in agreement with the scarce concentration of Na in the soil (291 ± 12 mg/kg DM). Magnesium was abundant in KEN (1434 ± 75 mg/kg FD, year 2012) and VOL (1334 ± 70). The content of K for DAY and KEN (13,147 ± 900 and 13,185 ± 900 mg/kg FD) was higher than for VOL and SIF; whereas Ca was in the range 340 ± 16–490 ± 28 mg/kg FD. The contents of Cu and Zn were higher in KEN (8.1 ± 0.3 and 25 ± 1 mg/kg FD) when compared to the other varieties and controls. The content of vitamin C is high for KEN and SIF and decreased significantly upon cooking (50% for KEN).     

Measurement of the total choline content in 48 commercial dairy products or dairy alternatives

In this work, the total choline and choline-containing moieties (free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine, lysophosphatidylcholine and sphingomyelin) of 48 dairy products or dairy alternatives available in Canada were determined by hydrophilic interaction liquid chromatography-tandem mass spectrometry (LC–MS/MS). The average total choline content for one serving of fluid milk and alternative (i.e. 250 mL as defined by Canada's Food Guide) was 32.9 ± 2.4 mg for cow's milk, 24.9 ± 0.1 mg for goat's milk and 31.2 ± 4.2 mg for soy beverage. The average total choline content for one serving of yogurt (175 g) was 25.6 ± 3.2 mg. One serving of cheese (50 g) provided 7.1 ± 1.1 mg of total choline on average. Our data show that for dairy products there is a negative correlation between the total choline content on a dry weight basis and the fat content (r = −0.734, P < 0.001). Overall, we determined the choline content of a variety of dairy products which can supplement the data in the existing United States Department of Agriculture (USDA) choline database and be used in accurately estimating dietary choline intake in epidemiological studies. Hence, dairy products are a good source of choline with low fat products generally being a better source of choline than high fat dairy products.     

Antioxidant components and antioxidant/antiradical activities of desert truffle (Tirmania nivea) from various Middle Eastern origins

Dried desert truffles from Bahraini, Iranian, Moroccan and Saudi origins were examined for their antioxidant and antiradical activities using four analytical methods: ferric reducing ability (FRAP), DPPH, deoxyribose, and nitric oxide (NO). Chemical constituents contributing towards these activities were also investigated. Generally, these truffles possessed varying concentration of antioxidant chemicals averaging 9.6 ± 0.15, 12.0 ± 8.34, 1860 ± 361, 1328 ± 167 and 293 ± 32 mg/100 g dw, for ascorbic, anthocyanins, total esterified phenolics, total free phenolics and total flavonoids, respectively; total carotenoids averaged 681 ± 245 g/100 g dw. Dried truffles also varied with regard to their antioxidant and antiradical activities. The FRAP value averaged 15.41 ± 3.51 mmol/100 g dw. Antiradical activity measured as percent inhibition of DPPH quenching averaged 30.6 ± 12.97% and EC₅₀ of 0.55 ± 0.38 mg. The average EC₅₀ of NO scavenging activity was 159.4 ± 69.3 μg, whereas the average percent inhibition of deoxyribose degradation was 55.9 ± 30.1%. The Iranian truffles yielded the highest in several variables, whereas the Moroccan truffles possessed the lowest values of many variables among the four tested samples. Significant correlation was established between total and free phenolics and FRAP values, and between flavonoids and percent radical inhibition using DPPH, NO and deoxyribose assays.     

The effect of black tea on risk factors of cardiovascular disease in a normal population

ObjectivesA prospective randomized controlled clinical trial determined the effect of Mauritian black tea consumption on fasting blood plasma levels of glucose, lipid profiles and antioxidant status in a normal population.MethodsThe study group (71%) consumed 3 x 200 ml of black tea infusate/day for 12 weeks without additives followed by a 3 week wash-out. The control group (29%) consumed equivalent volume of hot water for same intervention period.ResultsThe tea used had high levels of gallic acid derivatives (50 ± 0.4 mg/L), flavan-3-ols (42 ± 2 mg/L), flavonols (32 ± 1 mg/L) and theaflavins (90 ± 1 mg/L). Daily 9 g supplementation of black tea infusate induced, in a normal population, a highly significant decrease of fasting serum glucose (18.4%; p < 0.001) and triglyceride levels (35.8%; p < 0.01), a significant decrease in LDL/HDL plasma cholesterol ratio (16.6%; p < 0.05) and a non significant increase in HDL plasma cholesterol levels (20.3%), while a highly significant rise in plasma antioxidant propensity (FRAP: 418%; p < 0.001) was noted .ConclusionBlack tea consumed within a normal diet contributes to a decrease of independent cardiovascular risk factors and improves the overall antioxidant status in humans.     

Phenolic and mineral profiles of four Balkan indigenous apple cultivars monitored at two different maturity stages

Some primary and secondary metabolites, as well as mineral nutrients in pulp, peel and juice obtained from four Serbian indigenous apple cultivars (Kožara, Kolačara, Budimka and Šumatovka) collected at two different developmental stages were studied. With advanced maturation soluble solids content, total and reducing sugars increased, while l-ascorbic acid content and titratable acidity decreased. Thirteen phenolic compounds were quantified using LC–MS/MS. The total phenolic content (TPC) ranged from 9.37 to 1440 mg/100 g fw, and 0.83 to 7.84 mg/100 g fw in peel and pulp samples, respectively. Quercetin derivatives were the major detected polyphenolic group. Majority of determined phenolic compounds were influenced by cultivar and the best sources were cultivars Kolačara and Budimka. The content of flavonols (with the exception of quercitrin) varied significantly depending on maturity at harvest. With regard to mineral analysis, K was the most abundant ranging from 104 to 158 mg/100 g fw in peel, 74.4 to 93.3 mg/100 g fw in pulp, and 77.1 to 91.5 mg/100 g fw in juice samples. Obtained results provide detailed information on nutritional potential and chemical composition of tested apple cultivars and thereby could encourage their wider cultivation and consumption.