Potential of Turkish Kabuli type chickpea and green and red lentil cultivars as source of soy and animal origin functional protein alternatives

In this study, functional properties of proteins from Turkish Kabuli type chickpea (CPEs) and green and red lentil cultivars (LPEs) were characterized and compared with those of soy and animal proteins. The LPEs and whey protein isolate (WPI) showed higher soluble and total protein content than the other proteins. CPEs showed the highest oil absorption capacity (10.9-14.59 g/g), followed by LPEs (6.90 -10.44 g/g), soy protein extract (8.23 g/g), and egg white proteins (6.37 g/g). The highest water absorption capacities were obtained for bovine gelatin (BGEL) (8.84 g/g), CPEs (4.90-7.94 g/g) and soy protein isolate (7.94 g/g). The foaming capacities of BGEL and fish gelatin (FGEL), and emulsifying capacity of WPI were slightly higher than those of CPEs and LPEs, but most stable emulsions and foams were formed by chickpea and lentil proteins. The least gelling concentration of CPEs (5-7 g/100 g) came second after BGEL (3 g/100 g). The 2-D electrophoresis revealed the detailed isoelectric point (between 4.5 and 5.9) and molecular weight patterns of chickpea and lentil proteins. This study clearly showed that the functional properties of Kabuli chickpea proteins are superior than those of lentil proteins and most of the studied soy and animal proteins.Research Foundation of Izmir Institute of Technolog

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

Degradation of various fruit juice anthocyanins by hydrogen peroxide

Degradation kinetics of anthocyanins was studied in sour cherry nectar, pomegranate and strawberry juices at high hydrogen peroxide (H2O 2) concentrations (9.31-27.92 mmol l-1) at 10-30°C and in only sour cherry nectar at low H2O2 concentrations (0.23-2.33 mmol l-1) at 20°C. Degradation of anthocyanins followed the first-order reaction kinetics. Sour cherry anthocyanins were the most resistant to H2O2, followed by pomegranate and strawberry anthocyanins. Degradation of anthocyanins was also studied in sour cherry nectar and pomegranate juice in the presence of ascorbic acid at 60 and 80 mg l-1 concentrations at 20°C. At 80 mg level, ascorbic acid significantly accelerated the degradation of anthocyanins in sour cherry nectar at 4.65, 6.98 and 9.31 mmol l-1 H2O2 concentrations. In contrast, ascorbic acid at both 60 and 80 mg levels protected the anthocyanins from degradation by H2O2 in pomegranate juice.Ankara University Research Funds (Grant # 98.11.12.01

Development of antioxidant food packaging materials with controlled release properties

In this study, cellulose acetate (CA) films with different morphological features were prepared in order to control the release rates of low molecular weight natural antioxidants, L-ascorbic acid and L-tyrosine. Increasing CA content in the casting solution decreased the average pore size and porosity of the films, thus, reduced the diffusion rates of both antioxidants through the films. Although both antioxidants have similar molecular weights, L-tyrosine released into water much more slowly than L-ascorbic acid. The highest antioxidant activity in release test solutions was observed with highly porous L-tyrosine containing films. However, when the porosity of the films reduced, the antioxidant activity of L-ascorbic acid released into solution was found to be higher due to trapping of significant amount of L-tyrosine in dense films. The use of different antioxidants caused different changes in morphological and mechanical properties of the CA films. Varying the structural features of the films with the preparation conditions or using different surfaces of the films allowed the controlled release of each antioxidant. © 2009 Elsevier Ltd. All rights reserved

Fizikalno-kemijska svojstva i aktivnost kompozitnih jestivih gelova od želatine obogaćene lizozimom i polifenolima iz zelenog čaja

Research background. The use of gel-based systems as a novel method for the delivery of natural antimicrobial, antioxidant and bioactive compounds is a developing innovative solution for the food industry. This research aims to develop multifunctional active edible gels based on gelatine and its composites with improved mechanical properties. Experimental approach. Antilisterial and bioactive composite gels showing different physical and active properties from classical gelatine gel were developed by loading lysozyme and green tea extract into gelatine/starch and gelatine/wax composite gels. Mechanical properties, swelling profiles, colour, release profiles, and antimicrobial and bioactive properties of the gels were characterised. Results and conclusions. Gelatine/wax gels showed 1.3- to 2.1-fold higher firmness and cutting strength than gelatine and gelatine/starch composite gels that had similar firmness and cutting strengths. Work to shear of both composite gels was 1.4- to 1.9-fold higher than that of gelatine gel. The gelatine/starch gel showed the highest water absorption capacity. Green tea extract reduced soluble lysozyme in all gels, but composite gels contained higher amount of soluble lysozyme than gelatine gel. All the gels with lysozyme inhibited Listeria innocua growth in the broth media, while green tea extract showed antilisterial activity only in gelatine/wax gels. Gels with green tea extract showed antioxidant, antidiabetic (α-glucosidase and α-amylase inhibition), antihypertensive (angiotensin-converting enzyme inhibition) and antiproliferative activities (on Caco-2 human colon carcinoma cells). However, gelatine and gelatine/wax gels showed the highest antioxidant and antidiabetic activity. The gelatine/wax gels prevented phenolic browning, while green tea extract in other gels showed moderate or extensive browning. Novelty and scientific contribution. This work clearly showed the possibility of improving mechanical properties and modifying water absorption and controlled release profiles of gelatine gels using gelatine/starch and gelatine/wax composites. The novel composite gels reduced browning of incorporated polyphenols and showed antilisterial and bioactive properties.Pozadina istraživanja. Gelovi se sve više primjenjuju u prehrambenoj industriji kao inovativno rješenje za obogaćivanje hrane prirodnim antimikrobnim, antioksidacijskim i bioaktivnim spojevima. Svrha je ovoga rada bila razviti aktivne višenamjenske jestive gelove od želatine i njezinih kompozita s poboljšanim mehaničkim svojstvima. Eksperimentalni pristup. U radu je razvijen kompozitni gel s antilisterijskim i bioaktivnim sastojcima, čija su se fizikalna svojstva i aktivnost razlikovali od gela izrađenog od obične želatine. Gel je proizveden dodavanjem lizozima i ekstrakta zelenog čaja kompozitnim gelovima od želatine i škroba ili želatine i voska. Opisani su: mehanička svojstva, bubrenje, boja, način oslobađanja aktivnih sastojaka te antimikrobna i bioaktivna svojstva gelova. Rezultati i zaključci. Kompozitni gelovi od želatine i voska bili su od 1,3 do 2,1 puta čvršći i imali veće vrijednosti snage rezanja od same želatine i kompozitnog gela od želatine i škroba, koji su imali međusobno slična svojstva. Smično naprezanje oba kompozitna gela bilo je od 1,4 do 1,9 puta veće od one želatinoznog gela. Gel od želatine i škroba najbolje je upijao vodu. Ekstrakt zelenog čaja smanjio je topljivost lizozima u gelu, ali su kompozitni gelovi imali više topljivog lizozima od želatinoznog gela. Svi gelovi s lizozimom inhibirali su rast bakterije Listeria innocua u podlozi, dok je ekstrakt zelenog čaja imao antilisterijska svojstva samo u gelu od želatine i voska. Gelovi koji su sadržavali ekstrakt zelenog čaja imali su antioksidacijski, antidijabetički (inhibicija α-glukozidaze i α-amilaze), antihipertenzivni (inhibicija angiotenzin konvertirajućeg enzima) i antiproliferativni učinak (na Caco-2 stanice karcinoma debelog crijeva). Međutim, želatinozni te kompozitni gel od želatine i voska pokazali su najveću antioksidacijsku i antidijabetičku aktivnost. U gelovima od želatine i voska nakon dodatka ekstrakta zelenog čaja nije došlo do posmeđivanja uslijed oksidacije fenolnih spojeva, dok je ekstrakt zelenog čaja u ostalim gelovima prouzročio blago do intenzivno posmeđivanje. Novina i znanstveni doprinos. U ovom je radu prikazana mogućnost poboljšanja mehaničkih svojstava te modificiranja apsorpcije vode i kontroliranog otpuštanja aktivnih tvari iz gelova od želatine i škroba ili želatine i voska. U novim kompozitnim gelovima smanjilo se posmeđivanje dodanih polifenola, a gelovi su imali antilisterijska i bioaktivna svojstva

Bioactive, functional and edible film-forming properties of isolated hazelnut (Corylus avellana L.) meal proteins

This study aimed characterization of bioactive, functional and edible film making properties of isolated proteins from untreated (HPI), hot extracted (HPI-H), acetone washed (HPI-AW), and acetone washed and hot extracted (HPC-AW-H) hazelnut meals. The most bioactive protein extract was HPC-AW-H, followed by HPI-AW, HPI-H and HPI, based on antioxidant activity (TEAC and ORAC: 158-461mmolTrolox/kg), iron chelation (60.7-126.7mmolEDTA/kg), angiotensin-converting enzyme inhibition (IC50: 0.57-1.0mg/mL) and antiproliferative activity on colon cancer cells (IC50: 3.0-4.6mg/ml). Protein contents of HPI, HPI-H and HPI-AW (93.3-94.5%) were higher than that of HPC-AW-H (86.0%), but HPC-AW-H showed the best pH-solubility profile. The extracts showed good oil absorption (7.4-9.4g/g) and foaming, but limited water holding and gelling capacities, and emulsion stability. The protein extracts gave transparent, yellowish to brownish and reddish colored and water soluble edible films. The HPI gave the lightest colored films with acceptable mechanical properties (elongation up to 144% and tensile strength up to 4.9MPa). 1-D and 2-D electrophoresis clearly showed the molecular and isoelectric profiles of hazelnut proteins. The overall results of this study showed that the bioactive, solubility and gelation properties of hazelnut proteins could be improved by simple processes like acetone washing and/or heat treatment. The hazelnut proteins are valuable as multipurpose food ingredients.Foundation of Izmir Institute of Technology (IZTECH

Water-soluble antioxidant potential of Turkish pepper cultivars

In this work, 29 pepper cultivars that represent the diversity of types and varieties grown in Turkey were analyzed for water-soluble antioxidant capacity and phenolic and vitamin C contents. In addition, 14 non-Turkish cultivars were tested for comparison. Significant diversity was observed in the different cultivars with the most variation (7.4-fold) seen for total antioxidant capacity, which ranged from 2.57 to 18.96 mmol Trolox/kg. Vitamin C content for the peppers ranged from 522 to 1631 mg·kg-1, a 3.1-fold difference, whereas total phenolic content for the pepper cultivars ranged from 607 to 2724 mg·kg-1, a 4.5-fold difference. When cultivars were grouped by morphology/ use, it was found that some types had significantly more variation and higher antioxidant activities than other types. Thus, for water-soluble antioxidant capacity, most variation was seen in long, blunt-ended Çarliston types, whereas long, pointed Sivri peppers had the highest mean capacity. Bell-shaped Dolmalik and Sivri peppers had the most variation for phenolic content, but fancy Süs and Sivri types had the highest means for this trait. Dolmalik types showed the most variation for vitamin C content, whereas Süs and Sivri peppers had the highest means for this character. All three parameters were significantly and positively correlated with the strongest correlation between total antioxidant capacity and phenolic content (r = 0.71). The presence of significant variation for antioxidant content in Turkish germplasm indicates that this material can be used for improvement and genetic mapping of nutritional content in pepper

Salt tolerance in Solanum pennellii: antioxidant response and related QTL

<p>Abstract</p> <p>Background</p> <p>Excessive soil salinity is an important problem for agriculture, however, salt tolerance is a complex trait that is not easily bred into plants. Exposure of cultivated tomato to salt stress has been reported to result in increased antioxidant content and activity. Salt tolerance of the related wild species, <it>Solanum pennellii</it>, has also been associated with similar changes in antioxidants. In this work, <it>S. lycopersicum </it>M82, <it>S. pennellii </it>LA716 and a <it>S. pennellii </it>introgression line (IL) population were evaluated for growth and their levels of antioxidant activity (total water-soluble antioxidant activity), major antioxidant compounds (phenolic and flavonoid contents) and antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase) under both control and salt stress (150 mM NaCl) conditions. These data were then used to identify quantitative trait loci (QTL) responsible for controlling the antioxidant parameters under both stress and nonstress conditions.</p> <p>Results</p> <p>Under control conditions, cultivated tomato had higher levels of all antioxidants (except superoxide dismutase) than <it>S. pennellii</it>. However, under salt stress, the wild species showed greater induction of all antioxidants except peroxidase. The ILs showed diverse responses to salinity and proved very useful for the identification of QTL. Thus, 125 loci for antioxidant content under control and salt conditions were detected. Eleven of the total antioxidant activity and phenolic content QTL matched loci identified in an independent study using the same population, thereby reinforcing the validity of the loci. In addition, the growth responses of the ILs were evaluated to identify lines with favorable growth and antioxidant profiles.</p> <p>Conclusions</p> <p>Plants have a complex antioxidant response when placed under salt stress. Some loci control antioxidant content under all conditions while others are responsible for antioxidant content only under saline or nonsaline conditions. The localization of QTL for these traits and the identification of lines with specific antioxidant and growth responses may be useful for breeding potentially salt tolerant tomato cultivars having higher antioxidant levels under nonstress and salt stress conditions.</p

Zein and its composites and blends with natural active compounds: Development of antimicrobial films for food packaging

In this chapter the current developments in using biopolymer zein for active edible film-making are discussed with particular emphasis on antimicrobial packaging. Recent studies have showed the possibility of developing effective antimicrobial edible packaging materials through the incorporation of different natural antimicrobial compounds, including antimicrobial enzymes, peptides, and phenolic compounds, into zein films. The zein-based films that contain antimicrobial enzyme lysozyme and bacteriocin nisin have great potential as antilisterial edible packaging materials. Additionally, zein-based films that contain natural phenolic compounds might be suitable for antimicrobial, antioxidant, and/or bioactive packaging. The use of composites of zein with waxes and blends of zein with fatty acids enables researchers to obtain antimicrobial zein-based films with controlled release properties

Control of polyphenol oxidase in whole potatoes by low temperature blanching

Russet Burbank potatoes can be blanched up to 60 min at 50 °C without any loss in firmness and without appearance of browning on their peels, eyes or infected areas. Low temperature blanching (LTB) for 45 min did not cause a significant reduction in crude polyphenol oxidase (PPO) activity (12%). However, when heating time was extended to 60 min, the activity and specific activity of the enzyme were reduced by 27-45% and 22-43% respectively. The remaining enzyme extracted from heated potatoes was partially purified 3.3-3.75-fold by 0-95% ammonium sulphate precipitation and dialysis, and its kinetic parameters were determined. The comparison of the kinetic parameters of PPO in control (Km=10.3 mM and Vmax/Km=0.15) and in 60 min heated potatoes (Km=13 mM and Vmax/Km=0.054) indicated the reduced affinity of the remaining enzyme to its substrate. Thus, LTB at 50 °C for 60 min not only inactivated part of the PPO activity but also reduced the kinetic capacity of remaining enzyme. Extending heating time to 75 min caused the appearance of slight browning on the peels and eyes of potatoes and reduced their firmness. The observed browning was due to the sharp drop in the Km that caused the activation of the PPO. Heating at 50 °C did not affect lipoxygenase activity, but the Km of the enzyme dropped from 0.4 to 0.15 mM and the enzyme became kinetically more reactive at low substrate concentrations. Covalently bound pectin methylesterase considerably activated (38%) by heating and this caused the drop of pH in potato tissues