贮藏时间和温度对蓝莓花色苷微胶囊品质的影响

为了探究贮藏时间和温度对蓝莓花色苷微胶囊品质的影响,确定适宜的贮藏条件,该文研究微胶囊在?18、4和25℃下,贮藏6个月期间品质的变化。结果表明,以乳清蛋白联合多糖为壁材的微胶囊能确保贮藏期间花色苷被高效包封。贮藏期间微胶囊品质的下降可能是因分子间相互作用力减弱所致。贮藏3~4月间,微胶囊玻璃态转化温度出现大幅下降(P0.05),粉体稳定性变差。与其他贮藏温度相比,?18℃下贮藏可抑制微胶囊分子间相互作用力的减弱,使其具有更高的包埋产率(P0.05)和释放率(P0.05),保留更多的花色苷(P0.05)和其他酚类物质(P0.05)从而增强抗氧化活性(P0.05)。因此,花色苷微胶囊较适宜的贮藏时间为3个月,贮藏温度为?18℃。研究结果可为微胶囊的贮藏和应用提供理论依据。     

Valorization of cauliflower (Brassica oleracea L. var. botrytis) by-products as a source of antioxidant phenolics

The present study reports the development of two extraction protocols, with potential industrial applicability, to valorize cauliflower (Brassica oleracea L. var. botrytis) byproducts as a source of antioxidant phenolics. In addition, the nonionic polystyrene resin Amberlite XAD-2 was used to obtain purified extracts. The extract yield, phenolic content, phenolic yield, and correlation between the antioxidant activity and the phenolic content were studied. The water and ethanol protocols yield a phenolic content of 33.8 mg/g freeze-dried extract and 62.1 mg/g freeze-dried extract, respectively. This percentage increased considerably when the extracts were purified using Amberlite XAD-2 yielding a phenolic content of 186 mg/g freeze-dried extract (water extract) and 311.1 mg/g freeze-dried extract (ethanol extract). Cauliflower byproduct extracts showed significant free radical scavenging activity (vs both DPPH(*) and ABTS(*)(+) radicals), ferric reducing ability (FRAP assay), and capacity to inhibit lipid peroxidation (ferric thiocyanate assay). In addition, the antioxidant activity was linearly correlated with the phenolics content. The results obtained indicate that the cauliflower byproducts are a cheap source of antioxidant phenolics very interesting from both the industrial point of view and the possible usefulness as ingredients to functionalize foodstuffs.     

Berry phenolics and their antioxidant activity

Phenolic profiles of a total of 26 berry samples, together with 2 apple samples, were analyzed without hydrolysis of glycosides with HPLC. The phenolic contents among different berry genera varied considerably. Anthocyanins were the main phenolic constituents in bilberry, bog-whortleberry, and cranberry, but in cowberries, belonging also to the family Ericaceae genus Vaccinium, flavanols and procyanidins predominated. In the family Rosaceae genus Rubus (cloudberry and red raspberry), the main phenolics found were ellagitannins, and in genus Fragaria (strawberry), ellagitannins were the second largest group after anthocyanins. However, phenolic acids were dominant in rowanberries (genus Sorbus) and anthocyanins in chokeberry (genus Aronia). In the family Grossulariaceae genus Ribes (currants and gooseberry), anthocyanins predominated, as well as in crowberries (family Empetraceae genus Empetrum). In apples, hydroxycinnamic acids were the main phenolic subgroup. Extraction methods for berries and apples were studied to produce phenolic extracts with high antioxidant activity. Evaluation of antioxidant activity was performed by autoxidazing methyl linoleate (40 degrees C, in the dark). The extraction method affected remarkably both the phenolic composition and the antioxidant activity, but with statistical analysis the observed activity could not be well explained with the contents of individual phenolic subgroups.     

Effect of ultrasound emulsification on cheese aroma encapsulation by carbohydrates

The encapsulation of liquid cheese aroma (20%) in different carbohydrate matrices by spray-drying was investigated. Carbohydrate stabilized emulsions have been prepared by two emulsifying methods, ultrasonic or Ultra-Turrax treatments, and have been compared in terms of emulsion stability and encapsulation efficiency. The use of ultrasound is particularly effective to obtain a stable emulsion with maltodextrin as support, which is known for poor emulsification properties. In the same way, the spray-dried maltodextrin microcapsules were more effective for retaining cheese aroma when ultrasound (12.7 g/100 g of dry powder) was used for the emulsification step rather than Ultra-Turrax (10.7 g/100 g of dry powder). In terms of encapsulation efficiency, the best system of cheese aroma encapsulation is obtained using ultrasound for the emulsification step and modified starch as support (94.3%). With this support, the positive effect of ultrasound resulted in a lower microcaspsule size and in a higher aroma retention than when Ultra-Turrax was used (83.3%). Studies on the aroma profiles showed changes after encapsulation that depend not only on the nature of the support and the emulsification method but also on the interactions between the aroma compound and the matrix. In terms of flavor quality, the best system of cheese aroma encapsulation is obtained using ultrasound and maltodextrin as support.     

Lettuce and chicory byproducts as a source of antioxidant phenolic extracts

A process to obtain enriched antioxidant phenolic extracts from lettuce (baby, romaine, and iceberg cultivars) and chichory byproducts as a way to valorize these byproducts was developed. Two extraction protocols using water and methanol as solvent were used. Amberlite XAD-2 nonionic polymeric resin was used to purify the extracts. The extraction yield, phenolic content, and phenolic yield were evaluated as well as the antioxidant capacity of the extracts (DPPH, ABTS, and FRAP assays). Baby and romaine lettuce byproducts showed the highest water extract yields [27 and 26 g of freeze-dried extracts/kg of byproduct fresh weight (fw), respectively], whereas baby and iceberg lettuce showed highest methanol extract yields (31 and 23 g of freeze-dried extracts/kg of byproduct fw, respectively). Methanol extraction yielded a raw extract with a high phenolic content, the baby and chicory extracts being the richest with approximately 50 mg of phenolics/g of freeze-dried extract. Regarding the purified extracts, water extraction yielded a higher phenolic content, baby and chicory being also the highest with mean values of approximately 190 and 300 mg of phenolics/g of freeze-dried extract, respectively. Both raw and purified extracts from baby and chicory showed the higher antioxidant contents (DPPH, ABTS, and FRAP assays). The antioxidant capacity was linearly correlated with the phenolic content. The results obtained indicate that lettuce byproducts could be, from the industrial point of view, an interesting and cheap source of antioxidant phenolic extracts to funcionalize foodstuffs.     

Chemical composition, antioxidant properties, and thermal stability of a phytochemical enriched oil from Acai (Euterpe oleracea Mart.)

Phenolic compounds present in crude oil extracts from acai fruit ( Euterpe oleracea) were identified for the first time. The stability of acai oil that contained three concentrations of phenolics was evaluated under short- and long-term storage for lipid oxidation and phenolic retention impacting antioxidant capacity. Similar to acai fruit itself, acai oil isolates contained phenolic acids such as vanillic acid (1,616 +/- 94 mg/kg), syringic acid (1,073 +/- 62 mg/kg), p-hydroxybenzoic acid (892 +/- 52 mg/kg), protocatechuic acid (630 +/- 36 mg/kg), and ferulic acid (101 +/- 5.9 mg/kg) at highly enriched concentrations in relation to acai pulp as well as (+)-catechin (66.7 +/- 4.8 mg/kg) and numerous procyanidin oligomers (3,102 +/- 130 mg/kg). Phenolic acids experienced up to 16% loss after 10 weeks of storage at 20 or 30 degrees C and up to 33% loss at 40 degrees C. Procyanidin oligomers degraded more extensively (23% at 20 degrees C, 39% at 30 degrees C, and 74% at 40 degrees C), in both high- and low-phenolic acai oils. The hydrophilic antioxidant capacity of acai oil isolates with the highest phenolic concentration was 21.5 +/- 1.7 micromol Trolox equivalents/g, and the total soluble phenolic content was 1252 +/- 11 mg gallic acid equivalents/kg, and each decreased by up to 30 and 40%, respectively, during long-term storage. The short-term heating stability at 150 and 170 degrees C for up to 20 min exhibited only minor losses (<10%) in phenolics and antioxidant capacity. Because of its high phenolic content, the phytochemical-enriched acai oil from acai fruit offers a promising alternative to traditional tropical oils for food, supplements, and cosmetic applications.     

Changes in antioxidant effects and their relationship to phytonutrients in fruits of sea buckthorn (Hippophae rhamnoides L.) during maturation

Different fractions of sea buckthorn fruits were investigated for antioxidant activity and its relationship to different phytonutrients. Capacity to scavenge radicals of the crude extract, like the phenolic and ascorbate extracts, decreased significantly with increased maturation. The changes were strongly correlated with the content of total phenolics and ascorbic acid. Antioxidant capacity of the lipophilic extract increased significantly and corresponded to the increase in total carotenoids. The phenolic fractions made a major contribution to the total antioxidant capacity due to the high content of total phenolics. The lipophilic fractions were most effective if the comparison was based on the ratio between antioxidant capacity and content of antioxidants. The crude extract of fruits showed the highest inhibitory effect in both 2,2-azobis(2,4-dimethylvaleronitrile) (AMVN) and ascorbate-iron induced lipid peroxidations. The aqueous and ascorbate-free extracts showed higher inhibition in the AMVN assay, but lower inhibition in ascorbate-iron induced peroxidation, than the lipophilic extract.     

Effects of genotype and environment on the antioxidant properties of hard winter wheat bran

Recent consumer interest in controlling and preventing chronic diseases through improved diet has promoted research on the bioactive components of agricultural products. Wheat is an important agricultural and dietary commodity worldwide with known antioxidant properties concentrated mostly in the bran fraction. The objective of this study was to determine the relative contributions of genotype (G) and growing environment (E) to hard winter wheat bran antioxidant properties, as well as correlations of these properties to growing conditions. Bran samples of 20 hard winter wheat varieties grown in two locations were examined for their free radical scavenging capacities against DPPH, ABTS cation, peroxyl (ORAC), and superoxide anion radicals and chelating properties, as well as their total phenolics and phenolic acid compositions. Results showed significant differences for all antioxidant properties tested and multiple significant correlations between these properties. A factorial designed analysis of variance for these data and pooled previously published data showed similar results for four of the six antioxidant properties, indicating that G effects were considerably larger than E effects for chelating capacity and DPPH radical scavenging properties, whereas E was much stronger than G for ABTS cation radical scavenging capacity and total phenolics, although small interaction effects (GxE) were significant for all antioxidant properties analyzed. Results also showed significant correlations between temperature stress or solar radiation and some antioxidant properties. These results indicate that each antioxidant property of hard winter wheat bran is influenced differently by genotype and growing conditions.     

Identification and antioxidant potential of flavonoids and low molecular weight phenols in olive cultivar chemlali growing in Tunisia

Increasing interest in phenolic compounds in olives is due to their antioxidant and health-enhancing properties. In this study the phenolics in fruits of the Tunisian olive cultivar Chemlali were extracted by methanol-water and fractionated using Sephadex LH-20 column chromatography. The identification of phenolic monomers and flavonoids was based on separation by high-performance liquid chromatography equipped with a diode array detector followed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analysis. Oleuropein, a secoiridoid glycoside esterified with a phenolic acid, was the major compound. Eight phenolic monomers and 12 flavonoids were also identified in Chemlali olives. Five flavonoids were isolated and purified using Sephadex LH-20 column chromatography and preparative paper chromatography. The antioxidant activity of the extract and the purified compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and by using the beta-carotene-linoleate model assay. Acid hydrolysis of the extract enhanced its antioxidant activity. Hydroxytyrosol and quercetin showed antioxidant activities similar to that of 2,6-di-tert-butyl-4-methylphenol. A hydroxyl group at the ortho position at 3' on the B ring of the flavonoid nucleus could contribute to the antioxidant activity of the flavonoids.     

Rowanberry phenolics: compositional analysis and bioactivities

Berries contain a large variety of different phenolic compounds such as anthocyanins, flavonols, tannins, and phenolic acids. Due to variation in the nature and content of the phenolic compounds, the antioxidant effect and other bioactivities of berry phenolics are strongly dependent on the berry raw material as the activities differ between the different phenolic constituents. In the present study, wild rowanberries ( Sorbus aucuparia ) and four cultivated sweet rowanberries, Burka, Granatnaja, Titan, and Zoltaja, were characterized for their phenolic composition and screened for antioxidant, antimicrobial, and antiadhesive activities. The HPLC and LC-MS analyses of phenolic composition revealed that the main phenolic constituents were caffeoylquinic acids, varying from 56 to 80% total phenolics. The cultivated species contained less caffeoylquinic acids and more anthocyanins (up to 28.5%). The phenolics derived from wild rowanberries were significantly effective at inhibiting lipid oxidation both in liposomes and in emulsions, especially when assessed by inhibition of the formation of hexanal (86-97% inhibition depending on concentration). The increase in anthocyanin content in the cultivated species did not result in significantly increased antioxidant activity. Both wild and cultivated rowanberry phenolics exhibited a bacteriostatic effect toward Staphylococcus aureus . In addition, the phenolic extract from Zoltaja was weakly inhibitory toward Salmonella sv. Typhimurium, whereas both Zoltaja- and Granatnaja-derived phenolics retarded Escherichia coli growth. The phenolic extracts of wild rowanberries and Burka showed an inhibitory effect on hemagglutination of E. coli HB101 (pRR7), which expresses the M hemagglutinin. It can be concluded that cultivation of rowanberries resulted in increased anthocyanin content, but this did not diminish their bioactivity in comparison to wild rowanberries rich in caffeoylquinic acids.     

Antioxidant capacity in cranberry is influenced by cultivar and storage temperature

Ten cranberry (Vaccinium macrocarpon Aiton) cultivars were evaluated for oxygen radical absorbance capacity (ORAC), anthocyanins, and total phenolics contents after three months of storage at 0, 5, 10, 15, and 20 degrees C. The antioxidant capacity of cranberry was affected by cultivars and storage temperatures. Among the 10 cranberry cultivars used in this study, Early Black, Crowley, and Franklin had higher antioxidant capacities than the other cultivars. ORAC values, anthocyanins, and total phenolics contents increased during storage. The highest increases in antioxidant activity, anthocyanin, and phenolics contents occurred at 15 degrees C storage. Fruit stored at 20 degrees C had lower ORAC values than those stored at 15 degrees C. A positive relationship existed between ORAC values and anthocyanin or phenolic content in all 10 cranberry cultivars at different storage temperatures.     

Inhibition of hemoglobin- and iron-promoted oxidation in fish microsomes by natural phenolics

Natural phenolic antioxidants have been tested in hake (Merluccious merluccious) microsomes as inhibitors of lipid oxidation promoted by fish muscle prooxidants: hemoglobin (Hb), enzymatic NADH-iron and nonenzymatic ascorbate-iron. The phenolics selected were as follows: (a) a grape phenolic extract (OW), (b) a fraction (IV) with isolated grape procyanidins with a medium-low degree of polymerization and galloylation percentage, (c) hydroxytyrosol obtained from olive oil byproducts, and (d) a synthetic phenolic antioxidant, propyl gallate. All compounds delayed lipid oxidation activated by Hb, enzymatic NADH-iron, and nonenzymatic ascorbate-iron, excluding hydroxytyrosol that was not an effective antioxidant on oxidation promoted by nonenzymatic iron. The relative antioxidant efficiency was independent of the prooxidant system, IV > propyl gallate > OW > hydroxytyrosol, and showed a positive correlation with their incorporation into microsomes (p < 0.05). The reducing capacity or ability for donating electrons and the chelating properties may also contribute to the antioxidant activity of phenolics, although these factors were less decisive than their affinity for incorporating into the microsomes. Conversely, the inhibition of Hb oxidation by phenolics and their polarity did not seem to play an important role on antioxidant mechanism. These results stressed the importance of incorporating the exogenous antioxidants into the membranes where are located key substances for fish lipid oxidation (highly unsaturated phospholipids, iron-reducing enzymes, and endogenous alpha-tocopherol).     

Identification and quantification of antioxidant components of honeys from various floral sources

Little is known about the individual components of honey that are responsible for its antioxidant activity. The present study was carried out to characterize the phenolics and other antioxidants present in honeys from seven floral sources. Chromatograms of the phenolic nonpolar fraction of the honeys indicated that most honeys have similar but quantitatively different phenolic profiles. Many of the flavonoids and phenolic acids identified have been previously described as potent antioxidants. A linear correlation between phenolic content and ORAC activity was demonstrated (R(2) = 0.963, p < 0.0001). Honeys were separated by solid-phase extraction into four fractions for sugar removal and separation based on solubility to identify the relative contribution of each fraction to the antioxidant activity of honey. Antioxidant analysis of the different honey fractions suggested that the water-soluble fraction contained most of the antioxidant components. Specific water-soluble antioxidant components were quantified, including protein; gluconic acid; ascorbic acid; hydroxymethylfuraldehyde; and the combined activities of the enzymes glucose oxidase, catalase and peroxidase. Of these components, a significant correlation could be established only between protein content and ORAC activity (R(2) = 0.674, p = 0.024). In general, the antioxidant capacity of honey appeared to be a result of the combined activity of a wide range of compounds including phenolics, peptides, organic acids, enzymes, Maillard reaction products, and possibly other minor components. The phenolic compounds contributed significantly to the antioxidant capacity of honey but were not solely responsible for it.     

Antioxidant and antiradical activities in extracts of hazelnut kernel (Corylus avellana L.) and hazelnut green leafy cover

Phenolic compounds in the aqueous systems were extracted, from hazelnut kernel (HK) and hazelnut green leafy cover (HGLC), with 80% (v/v) ethanol (HKe and HGLCe) or 80% (v/v) acetone (HKa and HGLCa). The extracts were examined for their phenolic and condensed tannin contents and phenolic acid profiles (free and esterified fractions) as well as antioxidant and antiradical activities by total antioxidant activity (TAA), antioxidant activity in a beta-carotene-linoleate model system, scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, and reducing power. Significant differences (p < 0.05) in the contents of total phenolics, condensed tannins, and TAA existed among the extracts that were examined. HGLCa extract had the highest content of total phenolics (201 mg of catechin equivalents/g of extract), condensed tannins (542 mg of catechin equivalents/g of extract), and TAA (1.29 mmol of Trolox equivalents/g of extract) followed by HGLCe, HKa, and HKe extracts, respectively. Five phenolic acids (gallic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid) were tentatively identified and quantified, among which gallic acid was the most abundant in both free and esterified forms. The order of antioxidant activity in a beta-carotene-linoleate model system, the scavenging effect on DPPH radical, and the reducing power in all extracts were in the following order: HGLCa > HGLCe > HKa > HKe. These results suggest that both 80% ethanol and acetone are capable of extracting phenolics, but 80% acetone was a more effective solvent for the extraction process. HGLC exhibited stronger antioxidant and antiradical activities than HK itself in both extracts and could potentially be considered as an inexpensive source of natural antioxidants.     

Total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone

The total phenolics and antioxidant activities of fenugreek, green tea, black tea, grape seed, ginger, rosemary, gotu kola, and ginkgo extracts, vitamin E, and tert-butylhydroquinone, were determined. Grape seed and green tea were analyzed for their phenolic constituents using high-performance liquid chromatography. The total phenolics of the plant extracts, determined by the Folin-Ciocalteu method, ranged from 24.8 to 92.5 mg of chlorogenic acid equivalent/g dry material. The antioxidant activities of methanolic extracts determined by conjugated diene measurement of methyl linoleate were 3.4-86.3%. The antioxidant activity of the extracts using chicken fat by an oxidative stability instrument (4.6-10.2 h of induction time) followed a similar trend in antioxidant activity as determined by the Folin-Ciocalteu method. Seven phenolics in grape seed and green tea extracts were identified that ranged from 15.38 to 1158.49 and 18.3 to 1087.02 mg/100 g of extract, respectively. Plant extracts such as green tea and grape seed extracts can be used to retard lipid oxidation in a variety of food products.     

Quince (Cydonia oblonga Miller) fruit (pulp, peel, and seed) and Jam: antioxidant activity

To study the antioxidant activity of quince fruit (pulp, peel, and seed) and jam, methanolic extracts were prepared. Each extract was fractionated into a phenolic fraction and an organic acid fraction and was analyzed by high-performance liquid chromatography (HPLC)/diode array detection and HPLC/UV, respectively. Antiradical activities of the extracts and fractions were evaluated by a microassay using 1,1'-diphenyl-2-picrylhydrazyl. The phenolic fraction always exhibited a stronger antioxidant activity than the whole methanolic extract. Organic acid extracts were always the weakest in terms of antiradical activity, which seems to indicate that the phenolic fraction gives a higher contribution for the antioxidant potential of quince fruit and jam. The evaluation of the antioxidant activity of methanolic extracts showed that peel extract was the one presenting the highest antioxidant capacity. The IC50 values of quince pulp, peel, and jam extracts were correlated with the caffeoylquinic acids total content. Among the phenolic fractions, the seed extract was the one that exhibited the strongest antioxidant activity. The IC50 values of quince pulp, peel, and jam phenolic extracts were strongly correlated with caffeoylquinic acids and phenolics total contents. For organic acid fractions, the peel extract was the one that had the strongest antiradical activity. The IC50 values of quince pulp, peel, and jam organic acid fractions were correlated with the ascorbic acid and citric acid contents.     

Antioxidant activity of indigenous edible mushrooms

The current study was undertaken to measure the antioxidant potential from water and methanolic extracts of fruiting bodies of 23 species of mushrooms naturally grown in different geographic locations of India. The antioxidant ability of each species was analyzed for the total antioxidative status, employing multimechanistic antioxidative assays such as inhibition of lipid peroxidation, determination of reducing power, and free radical scavenging ability, in addition to determination of total phenolics and identification of phenolic acids by HPLC analysis, because the phenolics are known to contribute largely to antioxidant potential. The antioxidant potential of these varieties of mushrooms was determined by summing the antioxidative activity (AOA) of each variety by varied antioxidant assays followed by determining the relative percent of AOA defined as the "antioxidant index" (AI). On the basis of the AI, the mushroom species were graded as very high, high, moderate, and low. Termitomyces heimii was identified as the best variety, which showed 100% AI with 37 mg of phenolics/g of sample, 418 units of reducing power ability (RPA)/g, and an IC50 of approximately 1.1 mg (dry weight)/mL, free radical scavenging activity (FRS) in the water extract followed by 11.2 mg of phenolics/g, 275 units of RPA/g, and an IC50 of approximately 2.7 mg (dry weight)/mL of FRS in the methanolic extract. Following T. heimii, Termitomyces mummiformis exhibited an AI of 86% within the "very high" group. Potent inhibitions of lipid peroxidation of approximately 100 and 69% was also observed in T. heimii and T. mummiformis, respectively. Water extracts ranged from 34 to 49% and methanolic extracts varied from 20 to 32% on dry weight of mushroom fruiting body. Total phenolic compounds were higher in the water extracts (2-37 mg/g) than in methanolic extract (0.7-11.2 mg/g). The AOA measured in the water extract was better than that from the methanolic extract. HPLC analysis of phenolic acids in the two mushroom species, namely, T. heimii and T. mummiformis, displaying maximum AOA potential indicated a preponderance of tannic acid, gallic acid, protocatacheuic acid, and gentisic acid. Studies thus provide the precise antioxidant status of 23 indigenous species of mushrooms, which can serve as a useful database for the selection of mushrooms for the function of preparation of mushroom-based nutraceutics.     

Chitosan-alginate microcapsules for oral delivery of egg yolk immunoglobulin (IgY)

Chitosan-alginate microcapsules were evaluated as a method of oral delivery of IgY antibodies. Physical characteristics, encapsulation efficiency (EE%), the loading capacity for IgY (IgY loading percentage, %, w/w of microcapsules), gastro-resistance, and release characteristics of these microcapsules in vitro under varying pH were investigated. Optimum physical factors were established for preparation of homogeneous, spherical, and smooth microcapsules. IgY loading% was not significantly altered by pH of the encapsulation medium. Encapsulation efficiency was highest (73.93%) at a pH of 3.5, above which EE% decreased significantly (p < 0.05). IgY was released from microcapsules upon exposure to simulated intestinal fluid (SIF, pH 6.8), and decreasing pH increased significantly IgY release (p < 0.05). The stability of IgY in simulated gastric fluid (SGF, pH 1.2) was greatly improved by encapsulation in chitosan-alginate microcapsules, and the residual activity was not affected by pH of the encapsulation medium. Moreover, microencapsulated IgY was significantly resistant to pepsin hydrolysis. This approach may enable intact IgY to reach target microorganisms within the lower digestive tract.     

Storage elevates phenolic content and antioxidant activity but suppresses antiproliferative and pro-apoptotic properties of colored-flesh potatoes against human colon cancer cell lines

Colored-flesh potatoes are an excellent source of health-benefiting dietary polyphenols, but are stored for up to 3-6 months before consumption. This study investigated the effect of simulated commercial storage conditions on antioxidant activity (DPPH, ABTS), phenolic content (FCR) and composition (UPLC-MS), and anticancer properties (early, HCT-116 and advanced stage, HT-29 human colon cancer cell lines) of potato bioactive compounds. Extracts from seven potato clones of differing flesh colors (white, yellow, and purple) before and after 90 days of storage were used in this study. The antioxidant activity of all clones increased with storage; however, an increase in total phenolic content was observed only in purple-fleshed clones. Advanced purple-fleshed selection CO97227-2P/PW had greater levels of total phenolics, monomeric anthocyanins, antioxidant activity and a diverse anthocyanin composition as compared with Purple Majesty. Purple-fleshed potatoes were more potent in suppressing proliferation and elevating apoptosis of colon cancer cells compared with white- and yellow-fleshed potatoes. The extracts from both fresh and stored potatoes (10-30 μg/mL) suppressed cancer cell proliferation and elevated apoptosis compared with the solvent control, but these anticancer effects were more pronounced with the fresh potatoes. Storage duration had a strong positive correlation with antioxidant activity and percentage of viable cancer cells and a negative correlation with apoptosis induction. These results suggest that although the antioxidant activity and phenolic content of potatoes were increased with storage, the antiproliferative and pro-apoptotic activities were suppressed. Thus, in the assessment of the effects of farm to fork operations on the health-benefiting properties of plant foods, it is critical to use quantitative analytical techniques in conjunction with in vitro and/or in vivo biological assays.