Evaluating the Antioxidants, Whitening and Antiaging Properties of Rice Protein Hydrolysates.

Plant-derived protein hydrolysates have potential applications in nutrition. Rice protein hydrolysates (RPHs), an excellent source of proteins, have attracted attention for the development of cosmeceuticals. However, few studies have reported the potential application of RPH in analysis, and this study examined their antioxidant activities and the inhibitory activities of skin aging enzymes. The results indicated that the total phenolic and flavonoid concentrations were 2.06 ± 0.13 mg gallic acid equivalent/g RPHs and 25.96 ± 0.52 µg quercetin equivalent/g RPHs, respectively. RPHs demonstrated dose-dependent activity for scavenging free radicals from 1,1-diphenyl-2-picrylhydrazyl [half-maximal inhibitory concentration (IC50) = 42.58 ± 2.1 mg/g RPHs] and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (IC50 = 2.11 ± 0.88 mg/g RPHs), dose-dependent reduction capacity (6.95 ± 1.40 mg vitamin C equivalent/g RPHs) and oxygen radical absorbance capacity (473 µmol Trolox equivalent/g RPHs). The concentrations of the RPH solution required to achieve 50% inhibition of hyaluronidase and tyrosinase activities were determined to be 8.91 and 107.6 mg/mL, respectively. This study demonstrated that RPHs have antioxidant, antihyaluronidase, and antityrosinase activities for future cosmetic applications.

A DyP-Type Peroxidase of Pleurotus sapidus with Alkene Cleaving Activity.

Alkene cleavage is a possibility to generate aldehydes with olfactory properties for the fragrance and flavor industry. A dye-decolorizing peroxidase (DyP) of the basidiomycete Pleurotus sapidus (PsaPOX) cleaved the aryl alkene trans-anethole. The PsaPOX was semi-purified from the mycelium via FPLC, and the corresponding gene was identified. The amino acid sequence as well as the predicted tertiary structure showed typical characteristics of DyPs as well as a non-canonical Mn2+-oxidation site on its surface. The gene was expressed in Komagataella pfaffii GS115 yielding activities up to 142 U/L using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) as substrate. PsaPOX exhibited optima at pH 3.5 and 40 °C and showed highest peroxidase activity in the presence of 100 µM H2O2 and 25 mM Mn2+. PsaPOX lacked the typical activity of DyPs towards anthraquinone dyes, but oxidized Mn2+ to Mn3+. In addition, bleaching of ß-carotene and annatto was observed. Biotransformation experiments verified the alkene cleavage activity towards the aryl alkenes (E)-methyl isoeugenol, α-methylstyrene, and trans-anethole, which was increased almost twofold in the presence of Mn2+. The resultant aldehydes are olfactants used in the fragrance and flavor industry. PsaPOX is the first described DyP with alkene cleavage activity towards aryl alkenes and showed potential as biocatalyst for flavor production.

New Whitening Constituents from Taiwan-Native Pyracantha koidzumii: Structures and Tyrosinase Inhibitory Analysis in Human Epidermal Melanocytes.

Nontoxic natural products useful in skin care cosmetics are of considerable interest. Tyrosinase is a rate-limiting enzyme for which its inhibitor is useful in developing whitening cosmetics. Pyracantha koidzumii (Hayata) Rehder is an endemic species in Taiwan that exhibits tyrosinase-inhibitory activity. To find new active natural compounds from P. koidzumii, we performed bioguided isolation and studied the related activity in human epidermal melanocytes. In total, 13 compounds were identified from P. koidzumii in the present study, including two new compounds, 3,6-dihydroxy-2,4-dimethoxy-dibenzofuran (9) and 3,4-dihydroxy-5-methoxybiphenyl-2'-O-ß-d-glucopyranoside (13), as well as 11 known compounds. The new compound 13 exhibited maximum potency in inhibiting cellular tyrosinase activity, the protein expression of cellular tyrosinase and tyrosinase-related protein-2, as well as the mRNA expression of Paired box 3 and microphthalmia-associated transcription factor in a concentration-dependent manner. In the enzyme kinetic assay, the new compound 13 acted as an uncompetitive mixed-type inhibitor against the substrate l-3,4-dihydroxyphenylalanine and had a Km value against this substrate of 0.262 mM, as calculated using the Lineweaver-Burk plots. Taken together, our findings show compound 13 exhibits tyrosinase inhibition in human melanocytes and compound 13 may be a potential candidate for use in cosmetics.

Ubiquitous occurrence of chlorinated byproducts of bisphenol A and nonylphenol in bleached food contacting papers and their implications for human exposure.

The occurrence of bisphenol A (BPA), nonylphenol (NP), and their six chlorinated byproducts were investigated in 74 food contacting papers (FCPs) from China, the U.S.A., Japan, and Europe using a sensitive dansylation LC-MS/MS method. BPA (

Measuring antioxidant and prooxidant capacity using the Crocin Bleaching Assay (CBA).

The Crocin Bleaching Assay (CBA) appears in literature as an in vitro method for measuring antioxidant and prooxidant capacity of model dietary antioxidants, food formulations, pharmaceuticals, and biological samples. The assay is based on simple competitive reactions between a colored probe, crocin, and the test compounds/constituents for scavenging peroxyl radicals generated after thermolysis of a water-soluble azo-initiator. So far, several researchers in the fields of food chemistry, nutrition and clinical biochemistry have sporadically addressed critical views about advantages, limitations and potential field of CBA application. This chapter presents step-by-step critical aspects of CBA in order to assist standardization of its performance. Detailed procedures for calculation of two attributes of peroxyl radical scavenging reactions, the relative rate constant and "total antioxidant capacity", are also presented.

Formation of carbonyl groups on cellulose during ozone treatment of pulp: consequences for pulp bleaching.

The formation of carbonyl groups during the ozone treatment (Z) of eucalyptus (Eucalyptus grandis and Eucalyptus urophylla hybrid) kraft pulps and their behaviors during subsequent alkaline stages were investigated by the CCOA method with carbazole-9-carboxylic acid [2-(2-aminooxethoxy)-ethoxy] amide (CCOA) as the carbonyl-selective fluorescence label. Several pulp samples with or without lignin and hexenuronic acids (hexA) were used to elucidate the effects of these components when present in unbleached kraft pulp. Both hexA and lignin increased the formation of carbonyl groups on cellulose and hemicellulose during ozonation. It was concluded that radicals are likely formed when ozone reacts with either lignin or hexA. These carbonyl groups were involved in cellulose depolymerization during subsequent alkaline extraction stages with sodium hydroxide (E) and alkaline hydrogen peroxide (P, in ZEP or ZP). Their numbers decreased after E but increased during P when H2O2 was not stabilized enough. Several ways to minimize the occurrence of carbonyl group formation are suggested.

The influence of bleaching agent and temperature on bleaching efficacy and volatile components of fluid whey and whey retentate.

Fluid whey or retentate are often bleached to remove residual annatto Cheddar cheese colorant, and this process causes off-flavors in dried whey proteins. This study determined the impact of temperature and bleaching agent on bleaching efficacy and volatile components in fluid whey and fluid whey retentate. Freshly manufactured liquid whey (6.7% solids) or concentrated whey protein (retentate) (12% solids, 80% protein) were bleached using benzoyl peroxide (BP) at 100 mg/kg (w/w) or hydrogen peroxide (HP) at 250 mg/kg (w/w) at 5 °C for 16 h or 50 °CC for 1 h. Unbleached controls were subjected to a similar temperature profile. The experiment was replicated three times. Annatto destruction (bleaching efficacy) among treatments was compared, and volatile compounds were extracted and separated using solid phase microextraction gas chromatography mass spectrometry (SPME GC-MS). Bleaching efficacy of BP was higher than HP (P < 0.05) for fluid whey at both 5 and 50 °C. HP bleaching efficacy was increased in retentate compared to liquid whey (P < 0.05). In whey retentate, there was no difference between bleaching with HP or BP at 50 or 5 °C (P > 0.05). Retentate bleached with HP at either temperature had higher relative abundances of pentanal, hexanal, heptanal, and octanal than BP bleached retentate (P < 0.05). Liquid wheys generally had lower concentrations of selected volatiles compared to retentates. These results suggest that the highest bleaching efficacy (within the parameters evaluated) in liquid whey is achieved using BP at 5 or 50 °C and at 50 °C with HP or BP in whey protein retentate.

An effective degumming enzyme from Bacillus sp. Y1 and synergistic action of hydrogen peroxide and protease on enzymatic degumming of ramie fibers.

Enzymatic degumming, as an alternative to chemical processing, has attracted wide attention. However, to date, little information about other enzyme components with effective degumming except pectinase has been reported, and there is no report about the effect of bleaching agent (H2O2) on enzymatic degumming and combining enzymatic degumming and H2O2 bleaching process. In this study, we found that the crude enzyme of wild-type Bacillus sp. Y1 had a powerful and fast degumming ability. Its PGL activity was the highest at pH 9.6-10.0 and 60 °C and stable at pH 7-10.5 and 30-50 °C, having a wide scope of pH and temperature. Its PGL also had a high H2O2 tolerance, and the gum loss and brightness of fibers could be significantly improved when H2O2 was added into it for degumming. The synergistic action was also found between it and H2O2 on the degumming and bleaching of ramie fibers. All showed that it was very suitable for a joint process of enzymatic degumming and H2O2 bleaching. It also contained more proteins compared with a control pectinase, and its high protease content was further substantiated as a factor for effective degumming. Protease and pectinase also had a synergistic action on degumming.

The impact of iron on the bleaching efficacy of hydrogen peroxide in liquid whey systems.

UNLABELLED: Whey is a value-added product that is utilized in many food and beverage applications for its nutritional and functional properties. Whey and whey products are generally utilized in dried ingredient applications. One of the primary sources of whey is from colored Cheddar cheese manufacture that contains the pigment annatto resulting in a characteristic yellow colored Cheddar cheese. The colorant is also present in the liquid cheese whey and must be bleached so that it can be used in ingredient applications without imparting a color. Hydrogen peroxide and benzoyl peroxide are 2 commercially approved chemical bleaching agents for liquid whey. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been previously reported for whey bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how bleaching can impact flavor and functionality of dried ingredients. Currently, the precise mechanisms of off-flavor development and functionality changes are not entirely understood. Iron reactions in a bleached liquid whey system may play a key role. Reactions between iron and hydrogen peroxide have been widely studied since the reaction between these 2 relatively stable species can cause great destruction in biological and chemical systems. The actual mechanism of the reaction of iron with hydrogen peroxide has been a controversy in the chemistry and biological community. The precise mechanism for a given reaction can vary greatly based upon the concentration of reactants, temperature, pH, and addition of biological material. In this review, some hypotheses for the mechanisms of iron reactions that may occur in fluid whey that may impact bleaching efficacy, off-flavor development, and changes in functionality are presented. PRACTICAL APPLICATION: Cheese whey is bleached to remove residual carotenoid cheese colorant. Concerns regarding bleaching efficacy, off-flavor development, and functionality changes have been reported for whey proteins bleached with hydrogen peroxide and benzoyl peroxide. It is very important for the dairy industry to understand how whey bleaching can impact flavor and functionality of dried ingredients. Proposed mechanisms of off-flavor development and functionality changes are discussed in this hypothesis paper.

Influence of storage, heat treatment, and solids composition on the bleaching of whey with hydrogen peroxide.

UNLABELLED: The residual annatto colorant in liquid whey is bleached to provide a desired neutral color in dried whey ingredients. This study evaluated the influence of starter culture, whey solids and composition, and spray drying on bleaching efficacy. Cheddar cheese whey with annatto was manufactured with starter culture or by addition of lactic acid and rennet. Pasteurized fat-separated whey was ultrafiltered (retentate) and spray dried to 34% whey protein concentrate (WPC34). Aliquots were bleached at 60 °C for 1 h (hydrogen peroxide, 250 ppm), before pasteurization, after pasteurization, after storage at 3 °C and after freezing at -20 °C. Aliquots of retentate were bleached analogously immediately and after storage at 3 or -20 °C. Freshly spray dried WPC34 was rehydrated to 9% (w/w) solids and bleached. In a final experiment, pasteurized fat-separated whey was ultrafiltered and spray dried to WPC34 and WPC80. The WPC34 and WPC80 retentates were diluted to 7 or 9% solids (w/w) and bleached at 50 °C for 1 h. Freshly spray-dried WPC34 and WPC80 were rehydrated to 9 or 12% solids and bleached. Bleaching efficacy was measured by extraction and quantification of norbixin. Each experiment was replicated 3 times. Starter culture, fat separation, or pasteurization did not impact bleaching efficacy (P > 0.05) while cold or frozen storage decreased bleaching efficacy (P < 0.05). Bleaching efficacy of 80% (w/w) protein liquid retentate was higher than liquid whey or 34% (w/w) protein liquid retentate (P < 0.05). Processing steps, particularly holding times and solids composition, influence bleaching efficacy of whey. PRACTICAL APPLICATION: Optimization of whey bleaching conditions is important to reduce the negative effects of bleaching on the flavor of dried whey ingredients. This study established that liquid storage and whey composition are critical processing points that influence bleaching efficacy.

Alternative bleaching methods for Cheddar cheese whey.

UNLABELLED: Residual annatto colorant (norbixin) in fluid Cheddar cheese whey can be bleached. The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact the flavor of dried whey protein. The objective of this study was to evaluate alternative methods for bleaching liquid whey: ultraviolet radiation (UV), acid-activated bentonite (BT), and ozone (OZ). Colored Cheddar cheese whey was manufactured followed by pasteurization and fat separation. Liquid whey was subjected to one of 5 treatments: control (CT) (no bleaching; 50 °C, 1 h), HP (250 mg/kg; 50 °C, 1 h), UV (1 min exposure; 50 °C), BT (0.5% w/w; 50 °C, 1 h), or OZ (2.2g/h, 50 °C, 1 h). The treated whey was then ultrafiltered, diafiltered, and spray-dried to 80% whey protein concentrate (WPC80). The entire experiment was replicated 3 times. Color (norbixin extraction and measurement), descriptive sensory, and instrumental volatile analyses were conducted on WPC80. Norbixin elimination was 28%, 79%, 39%, and 15% for HP, BT, UV, and OZ treatments, respectively. WPC80 from bleached whey, regardless of bleaching agent, had lower sweet aromatic and cooked/milky flavors compared to unbleached CT (P < 0.05). The HP and BT WPC80 had higher fatty flavor compared to the CT WPC80 (P < 0.05), and the UV and OZ WPC80 had distinct mushroom/burnt and animal flavors. Volatile compound results were consistent with sensory results and confirmed higher relative abundances of volatile aldehydes in UV, HP, and OZ WPC80 compared to CT and BT WPC80. Based on bleaching efficacy and flavor, BT may be an alternative to chemical bleaching of fluid whey. PRACTICAL APPLICATION: The 2 approved chemical bleaching agents for whey, hydrogen peroxide (HP) and benzoyl peroxide (BP), negatively impact flavor of dried whey protein, and restrictions on these agents are increasing. This study evaluated 3 alternatives to chemical bleaching of fluid whey: UV radiation, ozone, and bentonite.

Isolation, fractionation and characterization of melanin-like pigments from chestnut (Castanea mollissima) shells.

UNLABELLED: Melanins are known as versatile biopolymers, but the utilizations are restricted by their poor solubilities. Therefore, well soluble ones or their analogs are much desired. In this article, a new procedure was developed for fractionation of the pigments isolated from chestnut (Castanea mollissima) shells, and 3 fractions (Fr. 1, Fr. 2, and Fr. 3) were obtained. The solubilities of all the fractions in waters of different pH and in common organic solvents were studied. The physicochemical properties of the fractions were characterized for the first time on the basis of combined chemical analyses and spectroscopic methods including ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), electron spin resonance (ESR), and solid-state ¹³C nuclear magnetic resonance (¹³C-NMR). All the fractions could be bleached by NaOCl and H2O2 and give a positive reaction for polyphenols, which are usually used as typical tests for allomelanins. Their UV-Vis, FT-IR, and ESR spectra resembled those of synthetic and some natural melanins. Elemental data and quantitative analyses of ¹³C-NMR spectra revealed that pigment-bound proteins and polysaccharides were the most abundant in Fr. 1, while Fr. 2 was presented with the highest aromaticity. PRACTICAL APPLICATION: We provided a new, simple, and inexpensive method to fractionate the melanin-like pigments from chestnut shells. This technique can be used to produce natural melanin-like food colorants with different solubilities from chestnut shells.

Partially purified components of Nardostachys chinensis suppress melanin synthesis through ERK and Akt signaling pathway with cAMP down-regulation in B16F10 cells.

UNLABELLED: Ethnopharmacological relevance Nardostachys chinensis has been used in folk medicine to treat melasma and lentigines in Korea. We investigated the inhibitory activities of Nardostachys chinensis in melanogenesis and its related signaling pathway. MATERIALS AND METHODS: Bioassay-guided fractionation of Nardostachys chinensis using solvent partitioning and purification with octadecylsilane open-column chromatography resulted in partial purification. The active 20% methanol chromatographic fraction from the ethyl acetate layer (PPNC) was used to investigate melanogenesis by melanin synthesis, tyrosinase activity assay, cAMP assay, Western blot and flow cytometric analyses in B16F10 mouse melanoma cells. RESULTS: PPNC markedly inhibits melanin synthesis and tyrosinase activity in a concentration-dependent manner. We also found that PPNC decreases microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein (TRP)-1, and dopachrome tautomerase (Dct) protein expressions and MITF and tyrosinase mRNA levels. Moreover, PPNC reduces intracellular cAMP levels and activates mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K)/Akt expression in B16F10 cells. The specific MEK/ERK inhibitor PD98059 and PI3K/Akt inhibitor LY294002, block the PPNC-induced hypopigmentation effect, and abrogate the PPNC-suppressed expression of melanogenic proteins such as MITF, tyrosinase, TRP-1, and Dct. Using flow cytometry, we elucidated whether PPNC directly induces ERK phosphorylation at the level of an intact single cell. PPNC shows marked expression of phosphorylated ERK in live B16F10 cells and abrogates PPNC-induced phosphorylated ERK by PD98059 treatment. CONCLUSIONS: PPNC stimulates MEK/ERK phosphorylation and PI3K/Akt signaling with suppressing cAMP levels and subsequently stimulating MITF and TRPs down-regulation, resulting in melanin synthesis suppression.

[Glycol plant extracts in the prescription of topical skin-whitening hydrogels]. / Zastosowanie glikolowych wyciagów roslinnych w recepturze hydrozeli o dzialaniu wybielajacym podawanych na skóre.

An attempt was made to produce and test, according to the guidelines of Polish Pharmacopeia VIII, new prescriptions of hydrogels which could be applied in the treatment of skin diseases associated with hyperpigmentation. Hydrogel formulations containing a substance of skin-whitening activity (arbutin) and glycol plant extract was produced on Carbopol Ultrez 10 base. Two glycol plant extracts of confirmed beneficial effect on skin were selected: an extract of ginkgo leaves and of rosemary. For comparative purposes also preparations with arbutin were produced in which propylene glycol was introduced instead of glycol plant extracts. The assumption of the carried out study was to investigate physicochemical properties of model formulations, estimation of arbutin pharmaceutical availability from the suggested formulations and the assessment of the effect of glycol plant extract components on the process of arbutin diffusion from the produced hydrogel formulations. The formulation viscosity parameters were determined using cone-plate digital rheometer. Gravimetric method was applied to estimate the kinetics of volatile components from the preparations. Potentiometric method was used to measure pH. The rate of arbutin release through a semipermeable membrane to the acceptor fluid was tested in vitro. Spectrophotometric method was used for the determination of the quantity of the released therapeutic substance at defined time intervals. All the proposed formulations are viscoelastic systems having yield stress. There is a strict dependence between rheological properties characterizing the tested hydrogels and the quantity of the arbutin released from them. The process of arbutin release to the acceptor fluid through a semipermeable membrane was most effective from the formulation containing glycol extract of ginkgo (F1A+M).

[Application extract of bearberry in the prescription of dermatological hydrogels on Carbopol base]. / Zastosowanie ekstraktu z macznicy lekarskiej w recepturze hydrozeli dermatologicznych wytworzonych na bazie carbopoli.

An attempt was made to estimate pharmaceutical availability of the components of dry extract of bearberry from model dermatological preparations of skin-bleaching activity. Formulations containing in their composition dry extract of bearberry were produced for this purpose. The preparations were produced on the base of two kinds of Carbopol: Carbopol Ultrez 10, Carbopol 980. Physicochemical properties of the produced preparations were tested. Viscosity parameters were determined using digital cone-plate rheometer. Gravimetric method was used to estimate the kinetics of volatile components from the preparations. Potentiometric method was applied to measure pH of the produced hydrogels. The rate of release of the dry extract components through a semipermeable membrane to the acceptor fluid was tested in vitro. Spectrophotometric method was used to determine the amount of released therapeutic substance at defined time intervals. The obtained results indicate that the kind of the applied gelating substance has a significant influence on rheological parameters and on the process of release of therapeutic substances from model hydrogels. The formulation with dry extract of bearberry on Carbopol Ultrez 10 base demonstrates higher value of the area under the curve of therapeutic substances release to acceptor fluid than the formulation produced on Carbopol 980 base. Also more beneficial rheological parameters of application were obtained for formulation F1-M (lower value of structural viscosity and yield stress). The suggested model formulations with dry extract ofbearberry of confirmed skin-bleaching effect may be the base for offering a new line of dermatological preparations applied in the treatment of melanoderma.