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This paper reports on the extraction of Moringa oleifera (MO) oil by using aqueous enzymatic extraction (AEE) method. The effect of different process parameters on the oil recovery was discovered by using statistical optimization, besides the effect of selected parameters on the formation of its oil-in-water cream emulsions. Within the pre-determined ranges, the use of pH 4.5, moisture/kernel ratio of 8:1 (w/w), and 300 stroke/min shaking speed at 40 °C for 1 h incubation time resulted in highest oil recovery of approximately 70% (g oil/g solvent-extracted oil). These optimized parameters also result in a very thin emulsion layer, indicating minute amount of emulsion formed. Zero oil recovery with thick emulsion were observed when the used aqueous phase was re-utilized for another AEE process. The findings suggest that the critical selection of AEE parameters is key to high oil recovery with minimum emulsion formation thereby lowering the load on the de-emulsification step. [ABSTRACT FROM AUTHOR]

Tiger nut ( Cyperus esculentus ) tuber contains oil that is high in monounsaturated fatty acids, and this oil makes up about 23% of the tuber. The study aimed at evaluating the impact of several factors and enzymatic pre-treatment on the recovery of pressed tiger nut oil. Smaller particles were more favourable for pressing. High pressure pre-treatment did not increase oil recovery but enzymatic treatment did. The highest yield obtained by enzymatic treatment prior to mechanical extraction was 33% on a dry defatted basis, which represents a recovery of 90% of the oil. Tiger nut oil consists mainly of oleic acid; its acid and peroxide values reflect the high stability of the oil. [ABSTRACT FROM AUTHOR]

Highlights: [•] Anthocyanins bind to human serum albumin. [•] Binding constants for anthocyanins ranged from 1.08×105 to 13.16×105 M−1. [•] The effect of anthocyanin structure on the strength of binding to HSA was pH dependent. [Copyright &y& Elsevier]

Abstract: Extracts from mango (Mangifera indica Linn.) cultivar Chok–Anan seed kernels were studied as active substances, since they are known as a good source of phenolic antioxidants with metal chelating and tyrosinase inhibitory activities. Response surface methodology (RSM) was used to investigate the effect of a combination of polysaccharides selected from gum arabic, maltodextrin and alginate on droplet size distribution, encapsulation efficiency (EE), stability and viscosity of W/O/W emulsions. In addition, the effects of stored emulsion on the properties of the encapsulated powder were studied. The results showed that there were interactions between polysaccharides which affected droplet size distribution, stability, viscosity and EE of multiple emulsions. The RSM showed a good fit to the proposed model with R 2 >0.83, 0.79 and 0.69 for viscosity, stability and EE, respectively, with significant correlations (p <0.05). The formulation which gave an optimal coating material was also a suitable coating mixture for preparation of encapsulated mango seed kernel extract powder. Moreover, if the polysaccharide combination is not appropriate for coating, the storage after emulsion preparation will have a greater effect on the properties of the encapsulated emulsion and powder. [Copyright &y& Elsevier]

Abstract: The antioxidant properties of caffeic acid and bovine serum albumin in oil-in-water and water-in-oil emulsions were studied. Caffeic acid (5mmol/kg emulsion) showed good antioxidant properties in both 30% sunflower oil-in-water (OW) and 20% water-in-sunflower oil emulsions (WO), pH 5.4, during storage at 50°C. Although bovine serum albumin (BSA) (0.2%) had a slight antioxidant effect, the combination of caffeic acid and BSA showed a synergistic reduction in the rate of development of rancidity, with significant reductions in concentration of total volatiles, peroxide value (PV) and p-anisidine value (PA) for both emulsion types. The synergistic increase in stability of the OW and WO emulsions containing BSA and caffeic acid was 102.9% and 50.4% respectively based on total oxidation (TOTOX) values, which are calculated as 2PV+PA, with greater synergy calculated if based on formation of headspace volatiles. The OW emulsion was more susceptible to the development of headspace volatiles by oxidation than the WO emulsion, even though the degree of oxidation assessed by the TOTOX value was similar. [Copyright &y& Elsevier]

Abstract: The flavour characteristics of fresh and processed pennywort juices treated by pasteurisation, sterilisation and high pressure processing (HPP) were investigated by using solid-phase micro-extraction combined with gas chromatography–mass spectrometry. Sesquiterpene hydrocarbons comprise the major class of volatile components present and the juices had a characteristic smell due to the presence of volatile compounds including β-caryophyllene, humulene, E-β-farnesene, α-copaene, alloaromadendrene and β-elemene. All processing operations caused a reduction in the total volatile concentration, but HPP caused more volatile acyclic alcohols, aldehydes and oxygenated monoterpenoids to be retained than pasteurisation and sterilisation. Ketones were not present in fresh pennywort juice, but 2-butanone and 3-nonen-2-one were generated in all processed juices, and 2-nonanone and 2-hexanone were present in pasteurised and sterilised juices. Other chemical changes including isomerisation were also reduced by HPP compared to pasteurisation and sterilisation. [Copyright &y& Elsevier]

Abstract: The antioxidant and tyrosinase inhibitory properties of extracts of mango seed kernel (Mangifera indica L.), which is normally discarded when the fruit is processed, were studied. Extracts contained phenolic components by a high antioxidant activity, which was assessed in homogeneous solution by the 2,2-diphenyl-1-picrylhydrazyl radical and 2,2′-azinobis (3-ethylbenzothialozinesulfonic acid) radical cation-scavenging assays and in an emulsion with the ferric thiocyanate test. The extracts also possessed tyrosinase inhibitory activity. Drying conditions and extraction solvent were varied, and optimum conditions for preparation of mango seed kernel extract were found to be sun-drying with ethanol extraction at room temperature. Refluxing in acidified ethanol gave an increase in yield and the obtained extract had the highest content of total phenolics, and also was the most effective antioxidant with the highest radical-scavenging, metal-chelating and tyrosinase inhibitory activity. The extracts did not cause acute irritation of rabbit skins. Our study for the first time reveals the high total phenol content, radical-scavenging, metal-chelating and tyrosinase inhibitory activities of the extract from mango seed kernel. This extract may be suitable for use in food, cosmetic, nutraceutical and pharmaceutical applications. [Copyright &y& Elsevier]

The antioxidant effects of β-carotene, oil-soluble (bixin) and water-soluble (norbixin) annatto preparations and mixtures of these carotenoids with virgin olive oil polar extract were assessed in bulk olive oil and oil-in-water emulsions stored at 60 °C. Norbixin was the only carotenoid that inhibited the oxidative deterioration of lipids in both systems. Though bixin and β-carotene did not retard autoxidation, their mixtures with the polar extract from virgin olive oil enhanced the antioxidant effect of the olive oil extract. Norbixin (2 mM) was of similar activity to δ-tocopherol (0.1 mM) in stored oil. The combination of norbixin with ascorbic acid or ascorbyl palmitate in oil showed a reduction in formation of volatile oxidation products but not in peroxide value, compared with the analogous sample lacking norbixin. In olive oil-in-water emulsions, norbixin (2 mM) reduced hydroperoxide formation to a similar extent as δ-tocopherol (0.1 mM), which in turn was a better antioxidant than α-tocopherol. A synergistic effect between norbixin and ascorbic acid or ascorbyl palmitate was observed in the emulsion systems. [Copyright &y& Elsevier]

Soluble oxalate in foods is major concern for kidney stone formers due to its tendency to increase urinary oxalate concentration. Phytate forms complexes with cations, which increases soluble oxalate by making cations unavailable to precipitate oxalate. Thus, in order to reduce soluble oxalate, bran samples (wheat, oat and barley) and bean samples (red kidney bean and white bean) were treated with phytase. Release of phosphate after phytate degradation and its association with calcium was determined. Phosphate concentration increased after application of phytase in all samples, but effect on soluble oxalate concentration varied. Wheat and oat bran showed significant reduction (P < 0.05) in soluble oxalate compared to bean samples. Wheat bran, oat bran and white bean had a lower calcium:phosphate ratio than barley bran and red kidney beans. Correlation of the calcium:phosphate molar ratio with release of phosphate depends on concentration of calcium ions and this influences soluble oxalate concentration. [ABSTRACT FROM AUTHOR]

Highlights: [•] The phytate concentration in beans and cereal brans increase the soluble oxalate concentration by binding of calcium. [•] Soluble oxalate is present at higher concentration in bran samples than in beans. [•] Oat bran has a high soluble:insoluble oxalate ratio due to a low concentration of minerals. [Copyright &y& Elsevier]

Abstract: Model oil-in-water emulsions containing epicatechin (EC) and epigallocatechin gallate (EGCG) showed a synergistic increase in stability in emulsions containing added albumin. EGCG showed a stronger synergy (35%) with ovalbumin than did EC. Oxidation of the oil was monitored by determining peroxide values and hexanal contents. The effect of bovine serum albumin (BSA) on model oil-in-water emulsions containing each of the green tea catechins [epicatechin gallate (ECG), EGCG, EC and epigallocatechin (EGC)] was studied during storage at 30°C. The green tea catechins showed moderate antioxidant activity in the emulsions with the order of activity being ECG≈EGCG>EC>EGC. Although BSA had very little antioxidant activity in the absence of phenolic antioxidants, the combination of BSA with each of the catechins showed strong antioxidant activity. BSA, in combination with EC, EGCG or EGC, showing the strongest antioxidant activity with good stability after 45 days storage. Model experiments with the catechins stored with BSA in aqueous solutions confirmed that protein–catechin adducts with antioxidant activity were formed between the catechins and protein. The antioxidant activity of the separated protein–catechin adducts increased strongly with storage time and was stronger for EGCG and ECG than for EC or EGC. [Copyright &y& Elsevier]

Abstract: β-Casein and α-casein showed radical-scavenging activities in aqueous solution, whereas bovine serum albumin (BSA), α-lactalbumin and β-lactoglobulin showed much weaker antioxidant activity, when assessed by the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging assay. However, β-casein and α-casein showed reduced antioxidant activity after storage at 30°C. An increase in radical-scavenging activity and a fall in fluorescence of the protein component were evident after 6h, when BSA, β-lactoglobulin or casein were mixed with EGCG, and excess EGCG was removed, indicating the formation of a complex with this protein on mixing. Storage of all the proteins with EGCG at 30°C caused an increase in the antioxidant activity of the isolated protein component after separation from excess EGCG. This showed that EGCG was reacting with the proteins and that the protein-bound catechin had antioxidant properties. The reaction of EGCG with BSA, casein and β-lactoglobulin was confirmed by the loss of fluorescence of the protein on storage, and the increase in UV absorbance between 250 and 400nm. The increase in antioxidant activity of BSA after storage with EGCG was confirmed by the ferric reducing antioxidant potential (FRAP) and the oxygen radical antioxidant capacity (ORAC) assays. [Copyright &y& Elsevier]

The leaves of the Thai vegetable, Teaw (Cratoxylum formosum Dyer) were extracted with ethanol to provide an extract that had antioxidant properties. The composition of the extract was studied by high-performance liquid chromatography with a diode array detector, and by electrospray ionization mass spectrometry. The main antioxidant component (peak 1) was chlorogenic acid, which was present at 60% of the extract. Three minor components were present at 7%, 3% and 2%, and other components that were present at lower concentrations were also observed. Treatment of the Teaw extract with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH⠐) caused a similar reduction in peak area of 55.2–58.1% for chlorogenic acid and the three minor components, indicating that these components had common structural features. Component 2 was identified as dicaffeoylquinic acid, and compounds 3 and 4 were identified as ferulic acid derivatives. The radical-scavenging activity of the Teaw extract was compared with α-tocopherol, BHT and chlorogenic acid, using the DPPH⠐ and 2,2′-azinobis (3-ethylbenzothialozinesulfonic acid) radical cation (ABTS⠐+) assays. The Teaw extract scavenged both free radicals more strongly than did α-tocopherol and BHT, and the activity of the extract was consistent with the concentration of chlorogenic acid that was present, confirming that this component is a major contributor to the antioxidant activity. The acute toxicity of the Teaw leaf extract was investigated in mice, and it was found that the LD50 of the extract was >32g/kg. Consequently, this plant is a promising source of a natural food antioxidant. [Copyright &y& Elsevier]

Abstract: Headspace solid phase microextraction (HS-SPME) has been used to isolate the headspace volatiles formed during oxidation of oil-in-water emulsions. Qualitative and quantitative analyses with an internal standard were performed by GC-FID. Four sample temperatures for adsorption (30, 40, 50 and 60 °C) and adsorption times in the range 10–25 min were tested to determine the conditions for the volatile concentration to reach equilibrium. The optimum conditions were at 50 °C for 20 min. The method was applied to monitor changes in volatile composition during oxidation of an o/w emulsion. SPME was a simple, reproducible and sensitive method for the analysis of volatile oxidation products in oil-in-water emulsions. [Copyright &y& Elsevier]

The effect of wheat heat damage was estimated using hard red winter (HRW) wheat varieties grown in Oklahoma, and analyses were performed on wheat kernels, flour, and isolated starch. Wheat kernels were analyzed by photoacoustic spectroscopy (PAS), flour was analyzed by DSC, capillary zone electrophoresis (CZE) and rheometry, while starch was analyzed by DSC. DSC data showed little difference in the temperatures of starch gelatinization. The ΔH values increased at 50 °C storage temperature. PAS data revealed differences in sensitivities to heat between the three cultivars. The pericap of cultivar Jagger was about five times more heat resistant than the pericarp of the other two cultivars. CZE maps showed that gluten proteins from cultivar 2137 was more affected by the 60 days and 50 °C treatment than the other two cultivars. Non-linear steady shearing showed that all heat-treated flours had lower viscosity, which suggests a deleterious effect on the potential performance of yeasted baked products. Viscoelastic properties of the Jagger untreated suspension sample showed strong gluten. The linear and non-linear viscoelastic behaviours of Jagger cultivar were less altered by heat treatment than were the other cultivars. [Copyright &y& Elsevier]

Whey is a by-product of cheese manufacturing and therefore investigating new applications of whey proteins will contribute towards the valorisation of whey and hence waste reduction. This study shows for the first time a detailed comparison of the effectiveness of gelatin and β-lactoglobulin (β-LG) as fining agents. Gelatin was more reactive than whey proteins to tannic acid as shown by both the astringency method (with ovalbumin as a precipitant) and the tannins determination method (with methylcellulose as a precipitant). The two proteins showed similar selectivity for polyphenols but β-LG did not remove as much catechin. The fining agent was removed completely or to a trace level after centrifugation followed by filtration which minimises its potential allergenicity. In addition, improved understanding of protein–tannin interactions was obtained by fluorescence, size measurement and isothermal titration calorimetry (ITC). Overall this study demonstrates that whey proteins have the potential of reducing astringency in red wine and can find a place in enology. [ABSTRACT FROM AUTHOR]

Abstract: The levels of health-related phytochemicals were determined in lettuce leaf and in strawberry, raspberry and blueberry fruits grown in near-commercial conditions under plastic films of three different UV transparencies. In the red lettuce Lollo Rosso, total phenolics, anthocyanin, luteolin and quercetin levels were all raised by changing from a UV blocking film to a film of low UV transparency, and to a film of high UV transparency. The related green lettuce, Lollo Biondo, cultivated under the same conditions, showed virtually no phytochemical responses to the same variation in UV levels. Overall, the phenolic levels of strawberries, raspberries, and blueberries were unresponsive to the UV transparency of the plastic film under which the crops were grown. The significance of these findings is discussed in relation to the nutritional quality of soft fruit and salad crops which are increasingly being grown commercially under plastic tunnels. [Copyright &y& Elsevier]

Abstract: Tea polyphenols, especially the catechins, are potent antimicrobial and antioxidant agents, with positive effects on human health. White tea is one of the less studied teas but the flavour is more accepted than that of green tea in Europe. The concentrations of various catechins in 13 different kinds of infusion were determined by capillary electrophoresis. The total polyphenol content (Folin–Ciocalteu method), the trolox equivalent antioxidant capacity (TEAC value determined with the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation) and the inhibitory effects of infusions on the growth of some microorganisms were determined. Five different infusions (black, white, green and red teas and rooibos infusion) were added to a model food system, comprising a sunflower oil-in-water emulsion containing 0% or 0.2% bovine serum albumin (BSA), and the oxidative stability was studied during storage at 37°C. Oxidation of the oil was monitored by determination of the peroxide value. The highest radical-scavenging activity observed was for the green and white teas. Emulsions containing these extracts from these teas were much more stable during storage when BSA was present than when it was not present, even though BSA itself did not provide an antioxidant effect (at 0.2% concentration). Rooibos infusion did not show the same synergy with BSA. Green tea and white tea showed similar inhibitions of several microorganisms and the magnitude of this was comparable to that of the commercial infusion 2 (C.I.2), “té de la belleza”. This tea also had an antioxidant activity comparable to green tea. [Copyright &y& Elsevier]