Content of flavonols and selected phenolic acids in strawberries and Vaccinium species: influence of cultivar,cultivation site and technique

The amounts of flavonols (quercetin, myricetin and kaempferol) and phenolic acids (ellagic, p-coumaric, caffeic and ferulic acids) were analysed in six strawberry cultivars and in the berries of genus Vaccinium (four blueberry cultivars, wild bilberry, wild bog whortleberry). Differences between strawberries from organic vs. conventional cultivation were investigated and the influence of geographical origin on phenolic compounds of strawberries and blueberries was studied. Three different extraction and hydrolysis procedures together with two HPLC methods with diode-array UV/vis detection were used. The varietal differences in the total content of the phenolics analysed were larger among the cultivated blueberries (from 4.4 to 9.2 mg/100 g, fresh weight) than among the strawberry cultivars (from 42.1 to 54.4 mg/100 g). Some regional differences were observed in the phenolic contents in blueberries and strawberries. Compared to conventional cultivation techniques, organic cultivation had no consistent effect on the levels of phenolic compounds in strawberries.     

Composition of flavonoids in fresh herbs and calculation of flavonoid intake by use of herbs in traditional Danish dishes

Many herbs are known as excellent sources of natural antioxidants, and consumption of fresh herbs in the diet may therefore contribute to the daily antioxidant intake. The present study was performed in order to quantify flavonoids in commonly eaten fresh herbs. Fifteen fresh herbs (basil, chives, coriander, cress, dill, lemon balm, lovage, oregano, parsley, rosemary, sage, spearmint, tarragon, thyme, and watercress) were analysed by HPLC and mass spectrometry. Five major flavonoid aglycones were detected and quantified by HPLC after acid hydrolysis: apigenin, isorhamnetin, kaempferol, luteolin, and quercetin. The highest levels of flavonoids were found in parsley (510–630 mg apigenin /100 g), lovage (170 mg quercetin/100g), mint (18–100 mg apigenin/100 g), and dill (48–110 mg quercetin/100 g). Mass spectrometric detection, using atmospheric pressure chemical ionisation (APCI), was used to verify the presence of flavonoids in the hydrolysed extracts of herbs. Some traditional Danish dishes contain herbs, particularly parsley, dill, cress and chives, and the contribution to the flavonoid intake by consumption of these dishes was calculated.     

Effect of semi-drying on the antioxidant components of tomatoes

Three tomato cultivars (Excell, Tradiro, and Flavourine) grown under hydroponic conditions in a commercial greenhouse in New Zealand were semi-dried at 42 °C. The semi-dried tomatoes contained low levels of 5-hydroxymethyl-2-furfural and were significantly (p < 0.05) darker (lower CIELAB L* values) and had a higher mean a*/b* value (1.6) than the fresh tomatoes (1.2). The mean total phenolics in the semi-dried samples of tomatoes (300 mg gallic acid equivalents, GAE/100 g dry matter (DM)) was significantly lower than that of fresh tomatoes (404 mg GAE/100 g DM). The mean total flavonoid, and lycopene contents in the fresh samples (206 mg rutin equivalents/100 g DM, 63 mg/100 g DM, respectively) also showed a significant decrease after semi-drying (179 mg rutin equivalents/100 g, 54 mg/100 g DM, respectively). Ascorbic acid content in fresh tomatoes (284 mg/100 g DM) decreased to 223 mg/100 g DM after drying. The total antioxidant activity of the semi-dried tomatoes (1783 μmole trolox equivalents antioxidant capacity (TEAC)/100 g DM) was significantly (p < 0.05) lower than that of the fresh samples (2730 μmole TEAC/100 g DM).     

Se improves indole glucosinolate hydrolysis products content, Se-methylselenocysteine content, antioxidant capacity and potential anti-inflammatory properties of sauerkraut

Selenium (Se) has a well-known role in prevention of chronic diseases associated with oxidative stress and inflammation. The objective was to produce Se-enriched sauerkraut and to study the effect of selenite addition on indole glucosinolate hydrolysis products, vitamin C, Se biotransformation and microbial quality. The antioxidant activity of sauerkraut and its ability to inhibit NO production in LPS-induced macrophages were also examined. White cabbage was naturally fermented with 0.3 mg of Na₂SeO₃/kg fresh cabbage (NFSe) or without Se addition (NF). Total Se content reached up to 1.29 μg/g d.m. (0.11 μg/g f.m.). Selenomethylselenocysteine was the major Se form found in NFSe cabbage. Se addition caused a slight reduction of ascorbigen (6%) and vitamin C (5%) contents in sauerkraut (P ? 0.05); however, lactic acid bacteria increased (3%), and the formations of indole-3-carbinol and indole-3-acetonitrile were markedly enhanced (74% and 13%, respectively). NFSe cabbage extracts showed higher (P ? 0.05) antioxidant activity (163 μmol trolox/g d.m.) and inhibition of NO production in LPS-induced macrophages (IC₅₀ = 44.0 μg/ml) than did NF cabbage extracts. Consequently, Se-enriched sauerkraut can be considered as a health-promoting food.     

干酪乳杆菌HDS-01发酵对酸菜品质和细菌群落结构的影响

添加分离自酸菜发酵液的干酪乳杆菌（Lactobacillus casei）HDS-01构建酸菜发酵微生物生态体系,利用高效液相色谱法、酸碱滴定法、高通量测序和实时定量PCR技术结合传统酶学分析方法等,研究酸菜发酵过程中理化因子和微生物群落的动态变化,评价L. casei HDS-01对酸菜品质及安全性的影响。结果表明,添加L. casei HDS-01发酵酸菜的pH在第3 d就下降至3.15±0.08,发酵初期乳酸菌数为（7.63±0.19）lg CFU/mL。在发酵酸菜各时期,乳酸代谢途径关键酶活力均显著高于自然发酵酸菜（P<0.05）。在发酵末期,乳酸、总酸和V_C含量分别为（7.88±0.38）、（8.45±0.38） g/L和（445.02±10.53）mg/kg,亚硝酸盐含量为（1.55±0.86）mg/kg。对酸菜样品进行感官评价发现,L. casei HDS-01发酵酸菜从发酵液清澈度、酸菜的色泽、香气、口味以及脆度等方面均优于自然发酵酸菜。此外,L. casei HDS-01发酵酸菜中乳杆菌属（Lactobacillus）始终保持优势地位（63.36%~95.79%）,降低了肠杆菌属（Enterobacter）（0.04%~2.26%）和假单胞菌属（Pseudomonas）（0.28%~25.84%）等致病菌丰度,调控了菌群多样性,缩短了发酵进程。本研究对发酵用菌种资源和功能菌的开发具有重要的实践意义。     

Fatty acid composition and CLA content in goat milk and cheese samples from Umbrian market

Goat dairy products are considered as a suitable alternative to cow milk products for some special categories of consumers (infants, old, and convalescent people). In the present research, a study on the lipid fraction of commercial goat milk and cheese samples purchased from Umbrian market was carried out. Particular attention has been paid to evaluating conjugated linoleic acid (CLA) content and determining some interesting nutritional indexes. The results of goat milk samples showed that saturated, monounsaturated and polyunsaturated fatty acid contents were on average 71.2, 23.4, and 3.8 %, respectively. CLA content (cis-9, trans-11 isomer) was on average 11.5 mg/100 g in milk. Considerable variability was observed for n6/n3 ratio that varied from 2.7 to 10.6 in the considered goat milk samples. With regard to goat cheese samples CLA concentration was on average 118.8 mg/100 g in fresh cheese and 217.7 mg/100 g in semi-hard cheese, and the difference was not significant. Interestingly, α-linolenic acid content was higher and n6/n3 ratio was lower in semi-hard with respect to fresh cheese samples (p < 0.05).     

Chemical modifications of casein occurring during industrial manufacturing of milk protein powders

The effect of milk acidification at different pH levels applied during the processing of various types of milk protein powders was first evaluated in the experimental samples of caseins, caseinates and milk protein concentrates. The absence of inorganic colloidal phosphorus was detected when milk was acidified to pH 4.60, whereas low levels (0.36–0.72 g/100 g of protein) were detected when mild milk acidification occurred. The extent of protein glycation and the occurrence of protein cross-linking were assessed in the same samples by measuring their furosine (5.7–427 mg/100 g of protein) and lysinoalanine (0.4–35.2 mg/100 g of protein) levels, respectively. In addition to heat treatments, the contents of these markers strictly depend on the presence of lactose and consequently on the effectiveness of the washing step applied during processing before drying to remove non-protein soluble components. The determination of these chemical markers in the samples permitted the identification of different technological conditions applied in the manufacturing of commercial milk protein powders with the same class.     

Antioxidant Activity,Total Phenolic Content and Selected Physicochemical Properties of White Mulberry (Morus Alba L.) Fruits

In this study, total phenolic content, antioxidant activity, mineral content and selected physicochemical properties of three white mulberry phenotypes (Morus alba L.) grown in Turkey were measured. Moisture, total soluble solids, total sugar, sucrose, reducing sugar, protein, ash, pH, titratable acidity, color (L, a, b), vitamin C, total phenolic, antioxidant activity of fruits were determined between 72.85–79.75 g/100 g fresh fruit, 21.25–28.50 g/100 g fresh fruit, 12.18–17.02 g/100 g fresh fruit, 1.57–4.36 g/100 g fresh fruit, 9.42–15.46 g/100 g fresh fruit, 0.82–0.89 g/100 g fresh fruit, 2.20–2.65 g/100 g fresh fruit, 5.70–5.86, 0.25–0.28 g/100 g fresh fruit, 31.24–68.69, ?2.46 to 15.68, 4.58–21.74, 10.15–21.50 mg/100 g fresh fruit, 18.16–19.24 μg gallic acid equivalent/mg of sample, and 33.96–38.96%, of sample respectively. Fruits were generally found high in P and low in Ca.     

Taurine content of raw and processed fish fillets/portions

The health benefits of seafood are well recognised and fish and fish products are increasingly being advocated as functional foods. Taurine is also well recognised as beneficial to cardiovascular health, and seafood is a good source of this compound. This study investigated the taurine content of different fish species and also the use of vacuum tumbling and injection procedures for introducing additional taurine into fish. The taurine content of fish purchased in supermarkets was in the order plaice (146), cod (108), mackerel (78) and farmed salmon (60 mg/100 g fresh weight). Spot-sample tests on 14 other fish species showed a wide range (6–176 mg/100 g fresh weight) in taurine contents. Vacuum tumbling and injection in/with a taurine/sodium tripolyphosphate solution were used successfully to enrich tuna cubes (800 mg/100 g fresh weight) and salmon sides (891 mg/100 g fresh weight), respectively, with taurine thus making them (potentially) functional foods. The added taurine was well retained in processed tuna cubes and did not adversely affect the sensory acceptability of the samples. Taurine retention in cooked taurine-enriched tuna cubes was best for grilling followed by microwave heating and steaming.     

Effect of blanching on the antioxidant properties of some tropical green leafy vegetables

Eight popularly consumed green leafy vegetables in Nigeria namely: Structium sparejanophora, Amarantus cruentus, Telfairia occidentalis, Baselia alba, Solanum macrocarpon, Corchorus olitorus, Vernonia amygdalina, and Ocimum gratissimum were blanched in hot water for 5 mins. The antioxidant properties of the fresh and blanched green leafy vegetables were subsequently determined. The total phenol, ascorbic acid and the antioxidant potentials as typified by reducing property and free radical scavenging activity was also determined. The results of the study revealed that blanching cause a significant (P<0.05) increase in the total phenol [fresh (0.1–0.3 g/100 g), blanched (0.2–0.6 g/100 g)] content of the green leafy vegetables except in Amarantus cruentus and Vernonia amygdalina where there was no change. Conversely, there was a significant (P<0.05) decrease in the vitamin C [fresh (43.5–148.0 mg/100 g), blanched (15.8–27.3 mg/100 g)], reducing property [fresh (0.5–1.5 absorbance), blanched (0.1–0.6 absorbance)] and free radical scavenging ability [fresh (20.0–51.4%), blanched (16.4–47.1%)] of the blanched green leafy vegetables except in Structium sparejanophora, where there was no change in the reducing property (0.6 absorbance) and free radical scavenging ability (59.8%) of the blanched vegetable. In view of this it could be concluded that blanching of vegetables though makes green leafy vegetables more palatable and less toxic, however it reduces their antioxidant properties drastically.     

Alpha-Chaconine and Alpha-Solanine Content of Potato Peels and Potato Peel Products

Twelve samples of raw and cooked potato peels from commercial potato varieties were analyzed for their α-chaconine and α-solanine content by high-performance liquid chromatography (HPLC). Raw peels contained 1.30–56.67 mg/100g peel (wet weight) α-chaconine and 0.5–50.16 mg/100g peel (wet weight) α-solanine. Raw flesh from the same potatoes contained 0.02–2.32 mg/100g flesh (wet weight) α-chaconine and 0.01–2.18 mg/100g flesh (wet weight) of α-solanine. Peels were cooked by baking, frying and baking-frying. The two types of fried peels contained more α-chaconine (2.18–92.82 mg/100g cooked peel) and α-solanine (1.09–72.09 mg/100g cooked peel). Four commercial potato peel products – wedges, slices, fried peels and baked-fried peels – contained 3.60–13.71 mg α-chaconine/100g cooked product and 1.60–10.48 mg α-solanine/100g cooked product.     

High-pressure liquid chromatographic determination of ascorbic acid in cooked sausages

The purpose of this paper was to study and optimize both extraction and high-pressure liquid chromatography (HPLC)-UV detection procedures to develop a proper method for the determination of ascorbic acid content in cooked sausages. A simple and sensitive reversed-phase HPLC method for the NH2-bonded phase has been described for the determination of ascorbic acid content in cooked sausages. Various extracting agents were tested to solubilize the vitamin, with 5% (wt/vol) metaphosphoric acid giving the best results. Samples were chromatographed with UV detection at 248 nm on a 25-cm Spherisorb NH2 cartridge with a 0.4-cm inside diameter with a mixture of 0.02 M potassium phosphate buffer solution (pH 3.6) and acetonitrile (40:60, vol/vol) for the mobile phase. The method's precision within a day was 1.2%, and its precision between days was 3.8%. The detection limit was 1.6 mg/100 g. Recovery ranged from 91.4 to 96.2% for ascorbic acid added to meat samples. Twenty samples of six different products were analyzed in duplicate. For the samples analyzed, the mean value for ascorbic acid ranged between 21.555 and 24.899 mg/100 g of fresh weight.     

Screening of macro- and bioactive microconstituents of commercial finfish and sea urchin eggs

Crude and lipid composition, tocopherols, carotenoids, sterols and squalene content, together with fatty acids profiles of commercial marine egg products are reported, namely (a) canned eggs of lumpfish (Cyclopteris lumpus), Atlantic salmon (Salmo salar), trout (Oncorhynchus mykiss), smoked herring (Clupea harengus), and sea urchin (Paracentrotus lividus), (b) fresh sea urchin (P. lividus) eggs, and (c) beeswax covered, dried and salted mullet (Mugil cephalus) skeins -Greek “Avgotaracho”. The protein content of marine eggs ranged from 8.7 to 33.7 g/100 g on a fresh weight (fw) basis. Among neutral lipids triacylglycerols predominated, except for mullet roe where wax and steryl esters comprised 75% of neutral lipids. Phosphatidylcholine was the major phospholipid, followed by phosphatidylethanolamine. Marine eggs contained 0.18–2.39 g/100 g fw long chain ω3 polyunsaturated fatty acids (PUFA), mainly docosahexaenoic acid (DHA) in finfish eggs and eicosapentaenoic acid (EPA) in urchin eggs. They also contained 86.2–342.0 mg cholesterol/100 g fw, low amounts of squalene and other sterols and significant amounts of tocopherols (0.45–4.4 mg/100 g) and carotenoids (0.31–11.4 mg/100 g). The commercial finfish and urchin eggs are food of high nutritive value providing significant amounts of protein, ω3 PUFA, phosphatidylcholine, carotenoids, and tocopherols, with fatty acids profiles that exhibit low atherogenic and thrombogenic potential.     

Identification and quantification of phenolic compounds from sunflower (Helianthus annuus L.) kernels and shells by HPLC-DAD/ESI-MS

Phenolic compounds were extracted from defatted sunflower (Helianthus annuus L.) kernels and shells and characterised by HPLC with diode array and electrospray ionisation (ESI) mass spectrometric detection in the negative mode. Quantification of individual compounds was carried out by external calibration. Among the eleven compounds analysed 5-O-caffeoylquinic acid was predominant amounting up to 59.1 mg/100 g in the shells and 3050.5 mg/100 g in the kernels. The specific fragmentation patterns of mono- and dihydroxycinnamoylquinic acids allowed the unambiguous distinction of several stereoisomers which have not been described for sunflower seeds and seed shells so far. The total phenolic content of about 4200 mg/100 g on a dry matter basis revealed defatted sunflower meal to be a promising source of phenolic compounds that might be recovered and used as natural antioxidants. Furthermore, the press residues originating from sunflower oil extraction were shown to be still rich in phenolic antioxidants, thus, providing the opportunity to valorize these by-products in terms of sustainable agricultural production.     

The effective parameters for subcritical water extraction of SDG lignan from flaxseed (Linum usitatissimum L.) using accelerated solvent extractor

The aim of this study was to investigate the effective parameters for subcritical water extraction of secoisolariciresinol diglucoside (SDG) lignan from flaxseed using accelerated solvent extractor. For this aim, the influence of extraction parameters such as material shape (flaxseed, ground flaxseed meal and flaxseed meal sticks), temperature (120, 140, 160 and 180 °C), extraction time (15, 30, 60 and 90 min), pressure (1.500 and 2.000 psi), fresh water (5, 40 and 100 %) and sample amount (5 and 10 g) was studied. SDG lignan analysis has been carried out by LC–MS/MS. It was shown that material shape, temperature, extraction time and sample amount had significant effect on SDG lignan content in water extracts (p < 0.05). The highest amount (12.94 mg/g) and extraction yield (72.57 %) were obtained at 180 °C for 15 min, 1.500 psi and 40 % fresh water using 5 g of flaxseed meal sticks.     

Lactic acid fermentation of onions

Lactic acid fermentation was conducted on sweet, white, and yellow storage onions to produce souronion. The onions were sliced to 0.3 cm thick, salt was added at 1.5, 2.0, and 2.5 g/100 g without or with sugar at 1.0 and 2.0 g/100 g, and the fermentation temperature was 18°C. Since onions do not have the necessary lactic acid bacteria for the anaerobic fermentation, onions were inoculated using either brine from sauerkraut or slices of cabbage. The fermentation produced souronion with pH between 3.25–3.35 and 1.2–1.5 g lactic acid/100 ml, which is in the range as that of sauerkraut. Sensory evaluation showed that the yellow storage souronion was a favorable product with respect to color, texture and flavor. The souronion had a tart acidic taste, characteristic of sauerkraut, with onion flavor but without the pungency of raw onions.     

Effect of domestic processes and water hardness on soluble sugars content of chickpeas (Cicer arietinum L.)

An HPLC method for sugar analysis on legumes has been applied to three different Spanish cultivars of chickpeas, to evaluate changes on the soluble sugar fraction (with special attention to α-galactosides) during domestic processing (soaking and cooking) using two types of water with different hardness. Processing liquids were also analysed. Ciceritol, was the main sugar in all the samples. Raffinose and stachyose concentrations were from 1.312 to 1.947 g/100 g in raw samples. Soaking liquids extracted less than 4.86% of the α-galactosides of raw seeds with no considerable amounts of flatogenic sugars. Decreases of raffinose + stachyose after processing were between 24.7 and 42.6%. Cooking liquid contents of α-galactosides ranged from 0.282 to 0.565 g/100 ml, (0.119–0.302 g/100 ml of flatogenic sugars). Statistical tests (ANOVA) showed that water hardness has no significant effect (p⩽0.05) on flatogenic sugar contents of final processed chickpeas.     

APPLICATION AND ADVANTAGES OF THE ENZYMATIC METHOD FOR THE ASSAY OF ASCORBIC AND DEHYDROASCORBIC ACIDS AND REDUCTONES Determination in Fresh and Canned Spinach

A new enzymatic method based on the reaction ascorbic acid +½O₂→ dehydroascorbic acid + H₂O permits assaying for ascorbic and dehydroascorbic acids in vegetable extracts. The method is carried out using a Clark's electrode which determines the oxygen uptake during the above reaction. The method applied to both fresh and canned spinach is specific and reproducible. Some interfering substances may reduce the specificity and precision of the method, but the addition of chelating agents or acetaldehyde eliminates these interferences. On adding boric acid, only the interfering reductic acid is assayed. The ascorbic and dehydroascorbic acid values for fresh spinach range between 528–919 mg/100g for ascorbic acid and from 21–81 mg/100g for dehydroascorbic acid. For canned spinach the ascorbic acid values ranged from 119–202 mg/100g and the dehydroascorbic acid values from 25–110 mg/100g. The method is easy and rapid and can be utilized advantageously for routine analyses.     

Chemical compounds and sensory assessment of kiwifruit (Actinidia chinensis (Planch.) var. chinensis): electrochemical and multivariate analyses

This study reports the analytical and sensory analyses made on selected kiwifruit genotypes (Actinidia chinensis (Planch.) var. chinensis) produced from seeds of fruit gathered in the Guangxi region of the People’s Republic of China. The analytical measurements of some soluble sugars, such as glucose and fructose, and non-volatile acids, such as malic and ascorbic acid, were carried out using innovative analytical procedures based on fast and selective devices that require very little or no sample treatment. The multivariate techniques, Principal Component Analysis and Cluster Analysis, useful when many variables are involved, allowed the classification of kiwifruit genotypes according to sugar and non-volatile acid contents and sensory properties. Citric acid, the major organic acid, ranged from 0.8 to 1.8 g per 100 g of fresh weight and malic acid content was 0.1–0.5 g per 100 g of fresh weight. The levels of fructose and glucose (present in approximately equal amounts in most of the genotypes analysed), were higher than that of sucrose in almost all the genotypes. Ascorbic acid content in kiwifruit samples from genotypes of Actinidia chinensis (Planch.) var. chinensis was higher than the typical mean content in Actinidia chinensis var. deliciosa (A Chev) cv Hayward. Sensory assessment showed that total fruit aroma and flavour were the best discriminating attributes and were highly correlated with overall quality. No consistent correlation was found between overall quality and the sensory attributes of sweetness, juiciness and firmness.     

Natural Antioxidants in Edible Flours of Selected Small Millets

Investigations were carried out on the natural antioxidants in edible flours of small millets. Total carotenoids content varied from 78–366 μg/100 g in the millet varieties with an average of 199 + 77, 78 + 19, 173 + 25, and 366 + 104 μg/100 g in finger, little, foxtail, and proso millets respectively. Analysis of carotenoids by HPLC for the presence of β-carotene showed its absence in the millets. HPLC analysis of vitamin E indicated a higher proportion of γ?and α-tocopherols; however, it showed lower levels of tocotrienols in the millets. Total tocopherol content in finger and proso millet varieties were higher (3.6–4.0 mg/100 g) than in foxtail and little millet varieties (～1.3 mg/100 g). Total antioxidant capacity in finger, little, foxtail and proso millets were 15.3 + 3.5, 4.7 + 1.8, 5.0 + 0.09, and 5.1 + 1.0 mM TE/g, respectively. From these studies it could be concluded that edible flours of small millets are good source of endogenous antioxidants.