Phenolic,alpha-tocopherol,beta-carotene and fatty acid composition of four promising jujube (Ziziphus jujuba Miller) selections

The phenolic, alpha-tocopherol, beta-carotene and fatty acid composition of four jujube selections were investigated in this study. Phenolic compounds, alpha-tocopherol and beta-carotene were analyzed with an HPLC device equipped with a diode array detector, and the fatty acid methyl esters were analyzed with QP 5050 GC/MS equipped with a CP-Wax 52 CB column. Among the jujube selections, considerable differences in phenolic and fatty acid contents were found. Catechin, caffeic acid, p-coumaric acid, ferulic acid, rutin, apigenin-7-glucoside, eriodictyol, quercetin, p-hydroxybenzoic acid, chlorogenic acid and syringic acid were isolated from leaves. Rutin content was very high in the leaves of all the jujube selections, ranging from 269.0 to 367.90 mg/100 g, followed by apigenin-7-glucoside (22.90–49.38 mg/100 g) and eriodictyol (5.06–6.27 mg/100 g). Seven phenolic compounds, catechin, caffeic acid, epicatechin, ferulic acid, rutin, p-hydroxybenzoic acid and chlorogenic acid, were isolated from fruits of jujube selections. Catechin level ranged from 2.46 to 3.74 mg/100 g, and rutin level ranged from 0.88 to 3.60 mg/100 g for fruits. Predominant phenolics were rutin and apigenin-7-glucoside for leaves, and catechin and rutin for fruits. Jujube leaves contained higher amounts of phenolic compounds than jujube fruits. Alpha-tocopherol was only detected in fruits of selections 20-Ç-22 and 20-Ç-52 (0.04 and 0.07 mg/100 g, respectively). Beta-carotene was significantly higher in 20-Ç-22 (35.0 μg/100 g) than in the other selections. Lipid content of the fresh fruits ranged from 0.06% to 0.10% among the four jujube selections. The predominant fatty acids in all jujube selections were oleic acid, linoleic acid, palmitic acid and palmitoleic acid. Unsaturated fatty acids comprised 68.54–72.44% of the total fat in jujube fruit.     

Total phenolic compounds and antioxidant potential of Hedychium spicatum Buch. Ham. ex D. Don in west Himalaya,India

Total phenolic compounds and antioxidant potential of Hedychium spicatum were analyzed for 16 different natural populations located in Uttarakhand (west Himalaya) for promotion as health or medicinal food. Total phenolic compounds varied among populations from 4.70 mg gallic acid equivalent (GAE) to 2.84 mg GAE/g dry weight. Three in vitro antioxidant assays, i.e. azinobisethylbenzothiazoline-6-sulphonic acid radical scavenging (ABTS) assay, diphenyl-2-picrylhydrazyl (DPPH) assay and ferric reducing antioxidant power (FRAP) assay, showed significant (p < 0.05) differences across populations. ABTS assay showed highest values of antioxidant potential ranging from 2.581 mM ascorbic acid equivalent (AAE) per 100 g to 1.91 mM AAE per 100 g dry weight, followed by FRAP assay (1.921–0.6635 mM AAE per 100 g). Lowest values were observed for DPPH assay, which varied from 0.549 to 1.059 mM AAE per 100 g dry weight. All assays (ABTS, DPPH and FRAP) showed significant (p < 0.05) correlation with total phenolic compounds. Total phenolic compounds showed a significant relationship (p < 0.05) to altitude.     

Antioxidant activity and phenolic content of fresh and dry nuts with or without the seed coat

Total antioxidant activities based on ABTS free radical scavenging activity and phenolic content of fresh or dry hazelnuts, walnuts and pistachios assayed with their seed coats changed between 3063 and 11,076 μmol trolox equivalents/100 g d.w. and 256 and 755 mg gallic acid equivalents/100 g d.w., respectively. The walnuts used in this study showed the highest antioxidant activity, followed by pistachios and hazelnuts. The removal of seed coat reduced the total antioxidant activity of hazelnuts, walnuts and pistachios almost 36, 90 and 55%, respectively. The total antioxidant activities of investigated fresh and dry nuts are not considerably different. However, phenolic content and antioxidant activity in hydrophilic and ethanolic fractions obtained by successive extraction of nuts showed some variation. The antioxidant activity in 1-serving portion of fresh or dry walnuts is equivalent to that in almost 2-serving portions of black tea, and 1.2–1.7-serving portions of green and Earl Grey tea. One-serving portions of dry hazelnuts and fresh or dry pistachios contained antioxidant activity equivalent to that in 0.7–1-serving portions of black tea. The antioxidant activity measurements correlated with phenolic content (r² = 0.70). This study showed the potential of using fresh or dry nuts to develop functional foods with high antioxidant activity.     

Seasonal variations in antioxidant components of cherry tomatoes (Lycopersicon esculentum cv. Naomi F1)

To evaluate seasonal variations in antioxidant components of greenhouse cherry tomatoes, the compositional profile of fruits (“Pomodoro di Pachino”, cv. Naomi F1) harvested at six different times of the year was compared. Among tomato antioxidants, phenolic compounds (naringenin content ranged from 1.84 to 9.04 mg/100 g, rutin from 1.79 to 6.61 mg/100 g) and α-tocopherol (40–1160 μg/100 g) showed the greatest variability. Ascorbic acid (31–71 mg/100 g), carotenoids (8350–15119 μg/100 g), phenolics and α-tocopherol concentration did not show definite seasonal trends, nor correlation with solar radiation or average temperature. Nevertheless, tomatoes harvested in mid-summer were characterized by lowered lycopene levels. Greenhouse growing conditions induced the accumulation of relatively high level of antioxidants for most of the year: one serving of raw tomatoes (100 g) could provide from 50% to 120% of the recommended daily intake of vitamin C, from 13% to 27% of that of vitamin A, from 0.4% to 12% of that of vitamin E, and from 15% to 35% of the flavonoid daily intake estimated for an Italian diet.     

Gas chromatography–mass spectrometry analysis of phenolic compounds from Carica papaya L. leaf

Phenolic compounds are important components in vegetable foods, infusions and teas for their beneficial effects on human health. The presence of such compounds, evidenced for the first time in Carica papaya leaves, could partially explain the pharmacological properties of this plant and demonstrates its importance in alimentation and daily intake. C. papaya leaves were extracted with methanol in a Soxhlet apparatus and later with a liquid–liquid extraction (LLE) with the aim of identifying and quantifying secondary metabolites from this plant, using gas chromatography–mass spectrometry (GC–MS) in the selected ion-monitoring (SIM) mode. Derivatization procedure of the extract was necessary to analyze the polar compounds in GC–MS. 5,7-Dimethoxycoumarin and polar molecules such as protocatechuic acid, p-coumaric acid, caffeic acid, chlorogenic acid, kaempferol and quercetin were detected and identified in qualitative analysis. The quantitative analysis has shown the presence of phenolic acids as the main compound, while chlorogenic acid was found in trace amounts, compared to the flavonoids and coumarin compounds. The quantities detected were 0.25 mg/g (dry leaf) for caffeic acid, 0.33 mg/g for p-coumaric acid and 0.11 mg/g for protocatechuic acid. Kaempferol and quercetin were 0.03 and 0.04 mg/g, respectively, while that for 5,7-dimethoxycoumarin was 0.14 mg/g.     

Sweet cherry phytochemicals: Identification and characterization by HPLC-DAD/ESI-MS in six sweet-cherry cultivars grown in Valle del Jerte (Spain)

Individual anthocyanin pigments and phenolic compounds were isolated, identified and quantified in six different sweet-cherry cultivars (Prunus avium L.) grown in Valle del Jerte area (Spain). An extractive-chromatographic method has been optimized for one-step extraction and simultaneous determination of all the studied components by HPLC/DAD-MS. The highest levels of phytochemicals were found in the autochthonous sweet-cherry cultivars that belong to the Protected Designation of Origin (POD) Cereza del Jerte. Van cultivar showed the lowest level of anthocyanin pigments and phenolic compounds. The most abundant anthocyanin pigment in all the studied cultivars was cyanidin-3-rutinoside (105 mg/100 g fresh weight (fwt) in Pico Negro sweet-cherry cultivar). The most abundant phenolic compound was the flavanol p-coumaroylquinic acid (130 mg/100 g fwt in Pico Negro sweet-cherry cultivar). In addition, chemical attributes (antioxidant activity, soluble solid content and pH) were also evaluated.     

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.     

Dietary fiber,phytochemical composition and antioxidant activity of Mexican commercial varieties of cactus pear

Cactus pear is one of the most important fruit in Mexican culture; however the phytochemical characterization of the whole cactus pear (pulp, peel and seeds) has not been studied. Therefore, the goal of this research was to evaluate the dietary fiber, vitamin C, total phenolic (TP), flavonoid and betalain concentrations and antioxidant activity (AOX) in the pulp, juice, peel and seeds of four Mexican commercial varieties of cactus pear. Rojo Cenizo and Rojo San Martín pulps presented concentrations of total dietary fiber, vitamin C, TP, betalains, and AOX of 145–166 g, 3–7 g ascorbic acid, 3–6 g gallic acid equivalents (GAE), 500–3444 mg betanin equivalents and 1044–5954 mg indicaxanthin equivalents, and 46–67 mm Trolox equivalents (TE) per kg, respectively. Rojo San Martín peel presented TP content over two times greater than the pulp, whereas AOX levels of Rojo San Martín and Verde Villanueva peels were 4–9 higher than their respective pulp. Cactus pear peel was the most important source of phytochemical compounds and AOX of the fruit, because of that it has to be considered in future applications for the formulation of new health-promoting ingredients and/or foods.     

Phenolic composition and radical scavenging activity of commercial Greek white wines from Vitis vinifera L. cv. Malagousia

Seven commercial white wine samples of the Malagousia cultivar were investigated for the first time with regard to their phenolic composition and radical scavenging activity. Total phenol content, corrected for ascorbic acid contribution (0–47 mg gallic acid equivalents/L of wine), ranged between 241 and 336 mg gallic acid equivalents/L of wine. On the other hand, the range for total hydroxycinnamates was 51.5–122.4 mg chlorogenic acid equivalents/L of wine and that for total flavanols 19.6–68.8 mg catechin equivalents/L wine. Fifteen phenolic compounds were identified and quantified by gas chromatography/mass spectrometry in the selective ion monitoring and high-performance liquid chromatography coupled with diode array detector. Tyrosol, caftaric, caffeic and 2-S-glutathionyl caffeoyl tartaric (GRP) acids were the major phenolics in all samples with mean concentrations of 12.32, 10.71, 10.17 and 4.79 mg/L wine, respectively. Catechin (3.75 mg/L) and p-coumaric acid (3.04 mg/L) followed in abundance. Variations in the values of GRP/caftaric (0.1–4.6) and caffeic/caftaric (0.4–4.2) acid concentrations, suggested differences in the degree of oxidation on one hand and hydrolytic processes during production and bottling on the other. Despite these variations, the radical scavenging activity of samples examined with DPPH and ABTS⁺ assays (mean value 0.85 and 3.45 mmol Trolox equivalents/L of wine) indicated a high efficiency in comparison to literature data on native and foreign white wines. The present findings can be useful for both technological and nutritional purposes.     

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.     

Characterization of phenolics,betacyanins and antioxidant activities of the seed,leaf, sprout,flower and stalk extracts of three Amaranthus species

Hydrophilic extracts from different parts including leaves, stalks, seeds, flowers and sprouts of 3 Amaranthus species (Amaranthus hypochondriacus, Amaranthus caudatus and Amaranthus cruentus) were characterized for their phytochemical profiles including the phenolics and betacyanins by UHPLC and LC–ESI–MS, and their antioxidant activities by FRAP and ORAC assays. The main betacyanins in Amaranthus samples were identified to be amaranthine and isoamaranthine. Eleven phenolic compounds (gallic acid, protocatechuic acid, chlorogenic acid, gentistic acid, 2,4-dihydroxybenzoic acid, ferulic acid, salicylic acid, rutin, ellagic acid, kaempferol-3-rutinoside and quercetin) were identified in the extracts of different parts of Amaranthus. The total phenolic content (TPC) ranged from 1.04 to 14.94 mg GAE/g DW; the total flavonoid content (TFC) ranged from 0.27 to 11.40 mg CAE/g DW; while the total betalain content (TBC) ranged from 0.07 to 20.93 mg/100 g DW. FRAP values ranged from 0.63 to 62.21 μmol AAE/g DW and ORAC ranged from 30.67 to 451.37 μmol TE/g DW. The leaves of Amaranthus showed the highest TPC, TFC, TBC, FRAP and ORAC values; while the seeds and stalks the lowest. There was a strong correlation between TPC, TBC, TFC and the antioxidant activity. The result suggests that all parts of the Amaranthus plant can be a good source of antioxidants.     

Radical scavenging,antioxidant and metal chelating activities of Annona cherimola Mill. (cherimoya) peel and pulp in relation to their total phenolic and total flavonoid contents

This study aimed to evaluate the total phenolic and flavonoid content, radical scavenging activity (by DPPH and ABTS tests) and antioxidant capacity (by β-carotene bleaching test) of Annona cherimola (cherimoya) fruits cultivated in Italy for human consumption. The metal chelating activity and ferric reducing power were also determined. A. cherimola peel and pulp were characterized by a total phenolic content of 14.6 and 12.6 mg chlorogenic acid equivalents/100 g fresh weight, respectively. A similar trend was observed with flavonoid content. Both extracts exhibited high antioxidant activity through different mechanisms of action. In particular, peel extract demonstrated the strongest free radical scavenging activity with an IC₅₀ value of 57.7 μg/mL. The same extract was more effective in preventing β-carotene oxidation (IC₅₀ value of 63.5 μg/mL after 60 min) and showed higher chelating ability (IC₅₀ value of 79.6 μg/mL) than pulp extract. This work demonstrated the high quality of cherimoya fruits cultivated in Italy, and recommends the peel of this fruit product that may be of interest from a functional point of view as a major source of natural antioxidants.     

Mangiferin and hesperidin metabolites are absorbed from the gastrointestinal tract of pigs after oral ingestion of a Cyclopia genistoides (honeybush tea) extract

Health-promoting properties such as antioxidative, anticarcinogenic, and cholesterol-lowering effects are described for mangiferin and hesperidin, the major phenolic compounds present in Cyclopia genistoides (honeybush). However, knowledge of their metabolic fate and their absorption from the gastrointestinal tract is very limited. The aim of this study was to determine the concentrations of mangiferin, hesperidin, and their metabolites in plasma, urine, and feces samples from pigs consuming an extract of Cyclopia genistoides. Pigs were administered up to 74 mg mangiferin per kilogram of body weight and 1 mg hesperidin per kilogram of body weight per day for 11 days. Plasma samples were collected at various time points on days 9 and 11 of the study and days 1 and 2 after termination of extract administration. Urine and feces were collected in fractions for 24 hours. In the plasma samples, the aglycone of mangiferin (norathyriol) was detected. Mean plasma concentrations ranged from 7.8 to 11.8 μmol/L. Six metabolites of mangiferin and hesperidin were detected in the urine, including methyl mangiferin, norathyriol, its monoglucuronide, hesperetin, hesperetin monoglucuronide, and eriodictyol monoglucuronide. Between 26.0% and 30.8% of the administered dose of hesperidin and only between 1.4% and 1.6% of mangiferin could be detected in the urine on days 9 and 11 of the study. Approximately 8.2% of the administered dose of mangiferin was determined in the feces. The main metabolite was norathyriol. Neither hesperidin nor metabolites ascribed to hesperidin intake were detected. The results suggest that formation of norathyriol from mangiferin occurs in vivo, and specific metabolites were identified in blood and excretion products in urine and feces. This study will aid in investigating the physiological functions of the parent compounds in vivo.     

Mineral and phenolic concentrations of mungbean [Vigna radiata (L.) R. Wilczek var. radiata] grown in semi-arid tropical India

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important pulse crop grown in south, east and southeast Asia. Mungbean seed samples harvested from field trials conducted in two environments in Hyderabad, India were utilized to determine genetic variation in the concentrations of minerals Fe, Ca, Mg, Zn, Cu, Mn, Se, Na, K and P and to determine the concentrations of phytic acid (PA) and phenolic compounds. Significant variations in Fe (35–87 mg/kg), Ca (1190–1580 mg/kg), Mg (970–1700 mg/kg), Zn (21–62 mg/kg), Cu (7.5–11.9 mg/kg), Mn (9.8–19.6 mg/kg), Se (0.21–0.91 mg/kg), K (8670–14,100 mg/kg) and P (2760–5170 mg/kg) were recorded in mungbean lines commonly grown in South Asia. The effect of the environment on the concentration of minerals in mungbean lines was observed. The Fe concentration of lines CN 9-5 and Harsha doubled when grown in soil with increased availability of Fe. The low PA concentration (2.6–3.8 g/kg) and the presence of phenolic compounds such as ferulic acid (1540–3400 μg/g) in mungbean may lead to increased bioavailability of micronutrients. Nutrient-rich mungbean should be included in diets to combat micronutrient malnutrition.     

Nutritional value of six multi-ingredient sauces from Burkina Faso

Multi-ingredient sauces (n=36), which are traditionally consumed with dishes containing starch (millet-based-tô, rice), were collected in rural Burkina Faso and analysed for their dry matter (DM), macronutrient (lipids, proteins) and micronutrient (iron, zinc, carotenoids and retinol) contents. DM content varied from 7.8% to 21.8% depending on the sauce. Groundnut sauces had the highest DM content. Protein contents were similar (22.2–32.3 g/100 g DM). The highest lipid contents were found in groundnut sauces (∼45 g/100 g DM). Sauces made from green-leafy vegetables formed a homogeneous group with a high content of retinol activity equivalents (RAE) (p<0.0001) and, to a lesser extent, of iron (p<0.05) compared to the dried okra or groundnut sauces. An isomer of β-carotene was detected in sauces made from green-leafy vegetables. The content of this isomer was strongly correlated with β-carotene content and not with cooking time.     

The concentrations of iron,calcium, zinc and phytate in cereals and legumes habitually consumed by infants living in East Lombok,Indonesia

There is a paucity of analysed data on contents of minerals and phytate in Asian complementary foods. Thus, cereals and legumes (n=27) consumed by Indonesian infants were analysed for iron, zinc and calcium using flame Atomic Absorption Spectrophotometry and for phytate using high performance liquid chromatography (HPLC). Results (per 100 g dry weight) showed unfortified cereals had lower concentrations of zinc (1.5–3.2 mg/100 g vs. 3.2–5.8 mg/100 g), iron (0.3–5.4 mg/100 g vs. 2.9–17.4 mg/100 g), calcium (5–48 mg/100 g vs. 41–926 mg/100 g) and phytate (hexa- and penta-inositol phosphates; 70–246 mg/100 g vs. 177–1042 mg/100 g) than legumes and lower phytate: mineral molar ratios. Tempe had the lowest concentration of phytate (236–366 mg/100 g vs. 763–1042 mg/100 g), and the lowest molar ratios of phytate: zinc (6.3–12.6 vs. 14.3–21.1) and phytate: iron (1.6–4.0 vs. 5.0–11.3) compared to other soybean products. Milling increased concentrations of iron and calcium in rice (1.2 vs. 0.4 mg/100 g, p=0.002; and 8.1 vs. 5.1 mg/100 g, p=0.029, respectively); but reduced zinc (1.6 vs. 1.7 mg/100 g, p=0.013). Boiling increased calcium concentrations in rice and rice flour (5.1–16.7 mg/100 g, p=0.004; and 8.1–31.4 mg/100 g, p<0.001, respectively); whereas frying decreased iron concentrations in tempe (13.3–6.1 mg/100 g, p=0.038). When expressed per infant portions, fortified cereals and tempe were the best sources of zinc, iron, and calcium, because of their relatively high mineral and low phytate contents.     

Antioxidant activity of methanolic extract of emblica fruit (Phyllanthus emblica L.) from six regions in China

The phenolic contents of methanolic extracts of emblica (Phyllanthus emblica L.) fruit from six regions in China were measured in this work. The antioxidant activities of these extracts were also evaluated. Total phenolic content was ranged from 81.5 to 120.9 mg gallic acid equivalents (GAE)/g and the flavonoid content was varied from 20.3 to 38.7 mg quecetin equivalents (QE)/g, while proanthocyanidin content was ranged from 3.7 to 18.7 mg catechin equivalents (CE)/g. Among all the methanolic extracts analyzed, the Huizhou sample exhibited a significantly higher phenolic content than other samples (P<0.05). The antioxidant activities were evaluated by in vitro experiments using scavenging assays of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, hydroxyl radicals, and superoxide anion radicals, chelating ability of ferrous ion, reducing power, and inhibition capability of Fe (II)-induced lipid peroxidation, respectively. The Huizhou sample was found to have the strongest antioxidant activities in scavenging DPPH radicals, superoxide anion radicals, and had the highest reducing power, while the Chuxiong sample showed the best performance in chelating iron and inhibiting lipid peroxidation. Furthermore, the Chuxiong sample exhibited a stronger inhibition activity of the hydroxyl radicals compared with other samples. The high correlation coefficient was existed between the phenolic content and superoxide anion radical scavenging activity, but no significant correlation was found between the former and hydroxyl radical scavenging activity. Methanolic extracts of emblica fruit from some selected regions exhibited stronger antioxidant activities compared to those of the commercial compounds (quercetin and BHA). It might be considered as a potential plant source of antioxidants.     

Simultaneous determination of epicatechin,syringic acid,quercetin-3-O-galactoside and quercitrin in the leaves of Rhododendron species by using a validated HPTLC method

A rapid and sensitive reverse phase high-performance thin-layer chromatographic (RP-HPTLC) method has been developed for the simultaneous determination of four bioactive phenolics, viz. epicatechin (1), syringic acid (2), quercetin-3-O-galactoside (3) and quercitrin (4) in the leaves of Rhododendron arboreum, Rhododendron campanulatum and Rhododendron anthopogon. HPTLC was performed on pre-coated RP-18 F_254S TLC plates. For achieving good separation, the mobile phase of methanol–5% formic acid in water, 50:50 (v/v) was used and densitometric determination of compounds was carried out at 290 nm in reflection/absorption mode. The method was validated in terms of linearity, precision, accuracy, and sensitivity. The calibration curves were linear in the range of 200–1200 ng for compounds 1, 3 and 4 and 400–2400 ng for compound 2. Lower limits of detection obtained for compounds 1–4 were 20, 40, 25 and 25 ng respectively, while the limit of quantification obtained were 50, 115, 75 and 70 ng respectively. The method was found to be reproducible and convenient for quantitative analysis of these compounds in Rhododendron species.     

Preliminary study of the chemical composition of rice milling fractions stabilized by microwave heating

The present paper presents a preliminary study of the chemical composition of local stabilized rice bran. The four rice-bran milling fractions, after stabilization by microwave heating on site at the rice mill, were analyzed for their chemical composition. The content of all fractions tested (in g/100 g) consisted of 8.7–18.9 fat, 8.8–15.2 protein, 8.5–12.6 moisture, 4.2–7.7 ash, 22.2–44.8 total carbohydrates (by difference) and 18.3–30.5 total dietary fibre. It is encouraging to note that total phenolic compounds of all fractions were detected at 257–488 mg ferulic acid equivalent per 100 kg, while carotenoid contents were found to be in the range of 58.7–216 μg/100 g. The amino acid composition varied within wide limits with proline, histidine and threonine as the amino acids. Higher concentrations of amino acids found (in decreasing order) were arginine, glutamic acid, aspartic acid and serine. Phosphorus and potassium were among the major mineral constituents of rice bran, with values up to 1633 mg/100 g. The first rice bran fraction was found to be highest in energy, fat and minerals and could be a very good source of dietary fiber and other nutrients.     

Ascorbic acid,vitamin A,and mineral composition of banana (Musa sp.) and papaya (Carica papaya) cultivars grown in Hawaii

Banana (Musa sp.) and papaya (Carica papaya) cultivars were harvested from different locations throughout Hawaii and analyzed for vitamin C (ascorbic acid), provitamin A (β-carotene, α-carotene, β-cryptoxanthin), and mineral composition. Dwarf Brazilian (“apple”) bananas had almost three times more vitamin C (12.7 mg/100 g fresh weight) than Williams fruit (4.5 mg/100 g). Also, Dwarf Brazilian bananas had 96.9 μg β-carotene and 104.9 μg α-carotene/100 g, whereas Williams fruit averaged 55.7 μg β-carotene and 84.0 μg α-carotene/100 g. Bananas contained higher concentrations of lutein than of the provitamin A pigments, α- and β-carotene. Papaya vitamin C content was 51.2 mg/100 g, with no differences among cultivars. Papaya provitamin A carotenoids averaged 232.3 μg β-carotene and 594.3 μg β-cryptoxanthin/100 g, and vitamin A ranged from 18.7 to 74.0 μg RAE/100 g. Lycopene was not detected in the yellow-fleshed cultivars, Kapoho, Laie Gold, and Rainbow, but the red-fleshed Sunrise and SunUp fruit contained 1350–3674 μg lycopene/100 g. Dwarf Brazilian bananas had higher P, Ca, Mg, Mn, and Zn contents than Williams fruit. The average K content for Hawaii's bananas was 330.6 mg/100 g. Papayas (100 g) contained 9% of the dietary reference intake (DRI) for Cu, 6–8% of the DRI for Mg, but less than 3% of the DRI for other minerals.