•Pectic polysaccharides were recovered from citrus canning processing water.•Water reuse system reduced water fee and the cost of polysaccharides recovery.•The COD of effluent decreased dramatically through polysaccharides recovery.•Recovered polysaccharides could be healthy food thickening and gelling agents.Canned citrus segments are popularly consumed worldwide with a large global market. However, the production needs chemical treatment to remove segments membranes, producing a large amount of acidic and basic effluents with very high chemical oxygen demand (COD), causing serious environmental problems. This research is focused on the plant scale recovery of pectic polysaccharides from the above acidic and basic processing water to decrease COD and develop a new product, through steps including water reuse (alternative), two-step filtration, concentration, ethanol precipitation and ethanol recovery. The yields of polysaccharides were 0.30% and 0.45% (w/v) from reused acidic and basic water, respectively, dramatically decreasing the COD by ∼75% from ∼10,000 mg/L, and having a great estimated output value of ∼$1.8 million annually for each factory. Polysaccharides from acidic water mainly contains homogalacturonan regions with ∼50% degree of esterification, whereas that from basic water was dominated with rhamnogalacturonan I regions with almost no esterification. The high viscosity of these branching polysaccharides, combined with gelling experiment results, suggested that both polysaccharides might be potential food thickening and gelling agents with large benefits to both the environment and the economy.Download high-res image (359KB)Download full-size image

•fCS oligosaccharides with different sulfation patterns were obtained from sea cucumbers.•Free radical depolymerization of fCSs was highly selective.•fCSs exert anticoagulant activity by selective inhibition of intrinsic tenase.•Depolymerization of fCSs should decrease adverse effects of activation FXII.•Sulfation pattern and molecular size are important to anticoagulant activity.Fucosylated chondroitin sulfates (fCSs) are structurally unusual glycosaminoglycans isolated from sea cucumbers that exhibit potent anticoagulant activity. These fCSs were isolated from sea cucumber, Isostichopus badionotus and Pearsonothuria graeffei. Fenton reaction followed by gel filtration chromatography afforded fCS oligosaccharides, with different sulfation patterns identified by mass and NMR spectroscopy, and these were used to clarify the relationship between the structures and the anticoagulant activities of fCSs. In vitro activities were measured by activated partial thromboplastin time (APTT), thrombin time (TT), thrombin and factor Xa inhibition, and activation of FXII. The results showed that free radicals preferentially acted on GlcA residues affording oligosaccharides that were purified from both fCSs. The inhibition of thrombin and factor X activities, mediated through antithrombin III and heparin cofactor II of fCSs oligosaccharides were affected by their molecular weight and fucose branches. Oligosaccharides with different sulfation patterns of the fucose branching had a similar ability to inhibit the FXa by the intrinsic factor Xase (factor IXa-VIIIa complex). Oligosaccharides with 2,4-O-sulfo fucose branches from fCS-Ib showed higher activities than ones with 3,4-O-disulfo branches obtained from fCS-Pg. Furthermore, a heptasaccharide is the minimum size oligosaccharide required for anticoagulation and FXII activation. This activity was absent for fCS oligosaccharides smaller than nonasaccharides. Molecular size and fucose branch sulfation are important for anticoagulant activity and reduction of size can reverse the activation of FXII caused by native fCSs.Download high-res image (189KB)Download full-size image

•Ultrasound assisted enzymatic process was influenced by temperature and ultrasonic intensity.•Ultrasound accelerated starch degradation and the enzymatic process catalyzed by glucoamylase.•Combination of ultrasound and glucoamylase resulted in the highest starch degradation extent.The present work investigates the synergistic impact of glucoamylase and ultrasound on starch hydrolysis. The extent of starch hydrolysis at different reaction parameters (ultrasonic intensity, temperature, reaction time) was analyzed. The hydrolysis extent increased with the reaction time and reached a maximum value under ultrasonic intensity of 7.20 W/mL at 10 min. Ultrasound did not alter the optimum enzymatic temperature but speeded up the thermal inactivation of glucoamylase. The evaluation of enzymatic kinetics and starch degradation kinetics indicated a promotion of the reaction rate and enzyme-substrate affinity. According to the thermodynamic results, sonoenzymolysis reactions require less energy than enzymolysis reactions. The measurement of molecular weight, solubility, thermal properties, and structures of the substrates revealed that sonoenzymolysis reaction generated greater impacts on starch properties. The molecular weight and radii of gyration decreased by 80.19% and 90.05% respectively while the starch solubility improved by 136.50%.

•BLPs reduced the activity of pancreatic lipase.•SPBLPs and UDBLPs significantly activated AMPK in dose dependent manner.•SPBLPs and UDBLPs reduced triglycerides synthesis by phosphorylating ACC.•SPBLPs and UDBLPs reduced sterols biosynthesis by mainly inhibiting SREBP-1.•SPBLPs promoted glucose consumption in HepG2 cells.The increasing rate of hyperlipidemia has drawn great attention and natural products may play a potential role in prevention of these disorders. Chinese bayberry leaves proanthocyanidin (BLPs) with epigallocatechin-3-O-gallate (EGCG) as its terminal and major extension units is unusual in the plant kingdom. Crude, purified and ultrasound depolymerized BLPs (CBLPs, SPBLPs and UDBLPs) were prepared with the aim to investigate their hypolipidemic mechanisms. BLPs inhibited the lipase activity in vitro and reduced the accumulation of total triacylglycerols (TAG) and cholesterol induced by oleic acid in HepG2 cells. SPBLPs and UDBLPS significantly increased the phosphorylation of AMP-activated protein kinase (AMPK) and thus reduced TAG and sterols biosynthesis by inhibiting its downstream proteins, such as acetyl-CoA carboxylase, 3-hydroxy-3-methylglutaryl-CoA reductase and sterol regulatory element-binding protein. BLPs also promoted glucose consumption in oleic acid induced HepG2 cells. Overall, this study suggests the hypolipidemic property and promotion of glucose consumption of BLPs via AMPK pathway.

•Air frying and conventional frying were used to produce potato chips.•The microstructure and digestibility of the potato chips were evaluated.•Air fried potato chips showed lower oil content.•Starch digestibility was influenced by the microstructure changes.The present study assessed the effects of conventional frying and air-frying on the microstructure, starch gelatinization, and digestibility of potato strips. The air fried potato showed less starch gelatinization (∼86%) and slightly higher starch digestibility (∼59%) when compared to the values of conventional frying (∼91% starch gelatinization, and ∼54% digestibility). The microstructure of the air-fried potato showed a compact and well-organized structure, whereas the surface of the conventionally fried potato appeared to be oil-soaked and crusty. After in vitro digestion, the conventionally fried potato had a normal cell structure with some lamellar residuals, while the air fried samples had a honeycomb like structure. The study showed that the differences in microstructural changes during conventional frying and air-frying could be correlated to the variation of starch digestibility.Download high-res image (158KB)Download full-size image

•Preparation methods on potato microstructure and digestion were evaluated.•Apparent morphology differences were observed after boiling, cooling and reheating.•The relative crystallinity of cooled was higher than reheated and boiled.•Cooling and reheating significantly affected the digestibility of potato.The effects of preparation method (boiled, cooled, and reheated) on the structural characteristics and in vitro digestibility of potato were investigated. The highest equilibrium starch hydrolysis was obtained after boiling (82.21%), followed by reheating (66.98%) and cooling (54.31%). The potato after cooling treatment exhibited a narrower melting temperature range and a higher melting enthalpy compared with the potatoes after boiling and the microwave reheating. X-ray diffraction patterns revealed that the relative crystallinity of the cooled potato was higher than those of the reheated and boiled potatoes, consistent with the results in melting enthalpy. Moreover, compared with the boiled potato, a large number of wrinkles were observed on the surface of the cooled potato, whereas after microwave reheating, larger clearances of starch granule regions were found. This study demonstrated that cooling and microwave reheating significantly affected the potato’s microstructure and digestibility and were suggested as alternative choices to prepare potato dishes.

•BLPs showed potent chemical, cellular antioxidant and antiproliferative capacities.•TPC and PAs content were in strong relation with chemical antioxidant activities.•Ultrasound treatment significantly degraded the mDP of PAs and improved CAA value.•Antiproliferative activity was in strong relation with PA contents.Chinese bayberry leaves proanthocyanidin (BLPs) contain epigallocatechin-3-O- gallate (EGCG) as its terminal unit and most of its extension units, which is unusual in the plant kingdom. The present study compared the antioxidant and anti-proliferative activities of BLPs prepared from different purification stages. Low-molecular-weight BLPs were prepared by ultrasonic treatment. Results revealed that the antioxidant activities of BLPs were strongly related to the content of total phenolics and proanthocyanidins; however, the cellular assay indicated that the mean degree of polymerization (mDP) played a vital role in the cellular antioxidant activity (CAA) of BLPs. The ultrasonic depolymerized BLPs with lower mDP (3.6 ± 0.3) exhibited a much higher CAA (EC50 = 0.042 ± 0.005 mg/mL) than other groups, which suggests that bioavailability is crucial to the cellular antioxidant potential of BLPs. Additionally, BLPs strongly inhibited HepG2 proliferation in a dose-dependent manner. Our results indicated that BLPs could be a valuable resource of bioactive compounds to promote consumer health.

•Beneficial and adverse effects of the potato on human health were reviewed.•The mechanisms of phytochemicals changes during cooking were discussed.•Steaming and microwaving are better cooking methods in retaining health.•Additives and cold storage are good way to low the GI of potato.Potato (Solanum tuberosum L) is an important food crop worldwide and a good source of vitamins, minerals and dietary fiber as well as phytochemicals, which benefits human body as nutrients supplementary and antioxidants. However, cooked potato is also considered as a high-glycemic-index food because of its high content of rapidly digestible starch, long-term consumption of which will increase the risk of cardiovascular disease and type-2 diabetes. Domestic cooking (boiling, frying, steaming, etc.) are usually adopted before potato consumption. The chemical, physical and enzyme modifications that occur during cooking will alter the potato’s antioxidant capacity and digestibility, which subsequently affected on the bioavailability of phytochemicals and the postprandial glycemic response of the human body. We reviewed the recent publications on the effects of domestic cooking on the nutrition, phytochemicals and the glycemic index changes of the cooked potato. Furthermore, the possible mechanisms underlying these changes were discussed, and additional implications and future research goals were suggested.

•The combination of physicochemical properties with aroma profiles in bayberry was applied.•The study focused on identifying the key aroma compounds of 11 bayberry cultivars using GC–MS–O.•The similarities and differences in the aroma of 11 bayberry fruits were studied by PCA.The present study aimed to differentiate the flavor (taste and odor) profiles of 11 Chinese bayberry cultivars (Myrica rubra). The physicochemical analysis for taste indicated the bayberry cultivars were quite different in soluble sugars, organic acids, color, total phenolics and anthocyanin contents. Sucrose was the main soluble sugar in bayberry fruit. Principal component analysis (PCA) of physicochemical properties indicated bayberries could be divided into 5 groups, and the Bi qi cultivar contained the highest brix/acid ratio demonstrating the sweetest taste. PCA of aroma-active profile for odor (analyzed by SPME–GC–MS–O) indicated bayberries could be divided into 3 groups: α-pinene (“pine” odor) for group 1 (four cultivars), β-caryophyllene and isocaryophyllene (“woody” odor) for group 2 (six cultivars), and ethyl acetate (“overripe” odor) for group 3 (one cultivar). Our research on the physicochemical and active-aroma of 11 bayberry cultivars will help to select suitable cultivars to increase consumer satisfaction.

•Domestic cooking methods on phytochemicals and antioxidant activity were systemic evaluated.•Stir-frying and air frying on phytochemicals and antioxidant were first studied.•Antioxidant activity was well accordance with total phenolic while showed least accordance with vitamin C.The effects of domestic cooking methods (boiling, baking, steaming, microwaving, frying, and stir-frying) and a new cooking method (air-frying) on the composition of phytochemicals (phenolics, anthocyanins, and carotenoids) and the antioxidant activity in purple-fleshed potatoes were investigated. Compared with raw potatoes, reductions of 23.59–90.42%, 7.09–72.44%, 7.45–83.15%, and 20.15–76.16% in the vitamin C, total phenolic, anthocyanin and carotenoid contents, respectively, was observed after cooking. Decreases of 7.88%, 21.55%, 22.48, 6.31%, and 61.38% in DPPH radical-scavenging activity was also observed after boiling, steaming, baking, microwaving and stir-frying, respectively, whereas an increase of 30.52% was noted after air-frying. A correlation analysis revealed that the antioxidant activity was in accordance with the total phenolic content and that this activity showed the lowest correlation with the vitamin C content. Among all of the cooking methods investigated in this study, stir-frying retained only slight levels of the phytochemicals and antioxidant activity observed in raw potatoes, whereas steaming and microwaving were able to retain most of the health-promoting compounds found in raw potatoes and may thus be suitable methods for cooking potatoes.

Eleven antioxidants including nine phenolic compounds (rutin, quercetin, hesperidin, hesperetin, naringin, naringenin, chlorogenic acid, caffeic acid, ferulic acid), vitamin E (α-tocopherol), and butylated hydroxytoluene (BHT) were selected to investigate their inhibitory effects on thermal oxidation of cholesterol in air and lard. The results indicated that the unoxidized cholesterol decreased with heating time whilst cholesterol oxidation products (COPs) increased with heating time. The major COPs produced were 7α-hydroxycholesterol, 7β-hydroxycholesterol, 5,6β-epoxycholesterol, 5,6α-epoxycholesterol, and 7-ketocholesterol. When cholesterol was heated in air for an hour, rutin, quercetin, chlorogenic acid, and caffeic acid showed a strong inhibitory effect. When cholesterol was heated in lard, caffeic acid, quercetin, and chlorogenic acid demonstrated inhibitory action during the initial 0.5 h (p < 0.05), with caffeic acid being the best inhibitor. Hesperetin, naringenin, caffeic acid, ferulic acid, vitamin E, and BHT could decrease the peroxide value during the initial 0.5 and 1 h (p < 0.05) in lard. It seemed that 200 ppm antioxidant could not obviously retard the long-term oxidation of cholesterol and lard under high temperature, but caffeic acid, quercetin, and chlorogenic acid displayed great untapped potential to prevent thermal oxidation of cholesterol 0.5 h at least. For the sake of health and flavor, fast stir-frying over a high flame is recommended. If baking or deep fat frying food in oil, it is best to limit cooking time to within 0.5 h.

Highlights•A new evaluation assay combined in vitro digestion with CAA was built.•Digesta had higher FPA but lower TPC and TAC than extracts.•Digesta had higher CAA but lower ABTS, FRAP, DPPH, ORAC than extracts.•TPC had higher correlation than TAC with CAA in digesta.•Digestion improved the correlation between CAA values and total phenolic contents.The traditional method of chemical extraction (i.e., extracts), combined with chemical antioxidant activity assays cannot assess the real antioxidant activity. In vitro digestion (i.e., digesta) with a cellular antioxidant activity (CAA) assay was developed for the determination of antioxidant activity in Chinese bayberry fruits. In this study, pretreatment methods were studied and the results showed that digesta had more free phenolic acids (FPA) but less total phenolic content (TPC) and total anthocyanin content (TAC) than extracts. Antioxidant activity assays, including ABTS, FRAP, DPPH, ORAC and CAA, were compared. Digesta had lower ABTS, FRAP and DPPH values but higher CAA values than extracts. FPA were better correlated with the chemical antioxidant assays in digesta. The correlations were high between TPC and CAA values in digesta (R2 = 0.96) but not extracts (R2 = 0.58). Higher correlations were also obtained between CAA and chemical assays in digesta.

Bee pollen has been praised for its good nutrition and therapeutic values. China is the largest producer in the world. Twelve common varieties of monofloral bee pollen collected from China’s main producing regions were selected for nutritional composition analysis, including proximate contents, dietary fibers, amino acid distribution, fatty acid composition, and mineral elements. The proximate compositions mostly met the specifications regulating pollen load quality of China. Proline and glutamic acids were found to be the predominant amino acids in the form of both total amino and free amino acids. Lysine was the relative limiting amino acid. The percentage of total essential amino acids (TEAA) to total amino acids (TAA) reached the nutrition recommendation of the Food and Agricultural Organization (FAO). The major fatty acids, presented as mean values, were C18:3 (25.1%), C16:0 (19.6%), C18:1 (17.3%), C18:2 (8.78%), C22:0 (4.07%), and C18:0 (2.96%) acids. The proportions of C18:3 were generally higher than those of C18:2, and the ratio of total unsaturated fatty acids (TUS) to total saturated fatty acids (TS) was >1.0, except for Nelumbo nucifera Gaertn. pollen for the characteristic absence of C18:3 acids. High levels of beneficial elements such as K, Ca, Mg, Zn, Fe, Mn. and Cu were observed in pollen samples. The contents of detrimental trace elements of Cd, Pb, and Hg were primarily lower or not detected. However, more attention should be paid to a large amount of Al, with a concentration of >100 mg/kg DW in most samples. There were some significant differences between samples. On the whole, the Chinese bee pollen was evaluated as a good complement to diet.

Cathepsin L (Cat L) in carp (Cyprinus carpio) dorsal muscles was purified and its molecular weight determined by SDS polyacrylamide gel electrophoresis (SDS–PAGE) was 36 kDa. Its optimal temperature and pH were 50 °C and 5.5, respectively. The results of the effects of specific substrates, activators and inhibitors on the enzymatic activity showed that Cat L belongs to the family of cysteine proteinases containing thiol. Compared to the control, the gel strength of surimi with the addition of purified Cat L decreased significantly by 24.33% while that of surimi with both purified Cat L and inhibitors increased by 13.7% and 21.6%, respectively, suggesting the participation of Cat L in the modori phenomenon occurring in carp surimi. Both the SDS–PAGE electrophoretic pattern and microstructure figure revealed that Cat L could hydrolyse the main protein in carp surimi and was one of the enzymes involved in the modori phenomenon.Highlights► Cathepsin L was purified from the dorsal muscles of carp (Cyprinus carpio). ► Cathepsin L was studied for its enzymatic characteristics. ► Cathepsin L could hydrolyse the main protein in carp surimi gel. ► Cathepsin L was one of the enzymes involved in the modori phenomenon.

The effects of different factors, including the material’s particle size, the extraction solvent, solid/solvent ratio, temperature, extraction time, the electrical acoustic intensity, liquid height and duty cycle of ultrasound exposure on the extraction yield of all-trans-β-carotene from citrus peels by ultrasound-assisted extraction (UAE) were investigated. The extraction yield was significantly affected by particle size. Dichloromethane caused the degradation of all-trans-β-carotene extracted during UAE. Ethanol showed a pronounced higher extraction yield during UAE in comparison with classical extraction (CE). The extraction yield of UAE had a peak value at 25 °C. In comparison with classical extraction, the extraction yield of UAE did not easily arrive at equilibrium. The extraction yield increased first, then decreased, then slightly increased with an increase in electrical acoustic intensity. The extraction yield of UAE decreased with increased liquid height. The extraction yield increased with increased duty cycle until equilibrium was achieved.

Leaves of each of two bayberry cultivars, Biqi and Dongkui, were divided into three categories by age, namely immature, intermediate, and mature. Phenolic compounds were analysed by the methods of HPLC-DAD and HPLC-UV-ESIMS. Gallic acid and EGCG were identified positively, and 13 other compounds (flavan-3-ol monomers, prodelphinidin oligomers, and flavonol glycosides) were partially identified. Gallic acid (7.5–87.8 mg/100 g) was the only phenolic acid detected and flavan-3-ols were abundant. Myricetin deoxyhexoside (535.4–853.0 mg/100 g) was the major flavonol glycoside. Among the three categories, immature leaves of both cultivars recorded the highest level of total phenolics, irrespective of whether they were measured by the Folin–Ciocalteu method (19404.0 mg/100 g in Biqi and 19626.0 mg/100 g in Dongkui) or as the sum of individual phenolic compounds (2255.9 mg/100 g in Biqi and 1797.1 mg/100 g in Dongkui). The results showed that bayberry leaves are a potentially rich source of beneficial phenolics.Highlights► Fifteen low-molecular-weight phenolic compounds were identified. ► Some of the compounds are never reported in bayberry leaves before. ► The compounds identified include phenolic acid, flavan-3-ols, and flavonols. ► Flavan-3-ols and flavonol glycoside are abundant. ► Immature leaves of two cultivars record the highest level of total phenolics.

The naturally dropped fruits of nine mandarin cultivars were collected and evaluated for their potential use in traditional Chinese medicine (TCM) or as nutraceutical materials. The main bioactive substances were analysed, including four flavanone glycosides (narirutin, naringin, hesperidin, and neohesperidin), two polymethoxlated flavones (nobiletin and tangeretin), and another two compounds of limonoid, and synephrine. The total phenolic content (TPC) and antioxidant capacity were determined by Folin–Ciocalteu, FRAP, DPPH, and ABTS assays. Hesperidin and narirutin were the main flavanones in all tested cultivars. Naringin and neohesperidin were not detected in any of the mandarin cultivars except for Ougan, which contained 10.6 ± 0.6 mg/g naringin. The highest contents of nobiletin and tangeretin were found in Zhuhong (13.7 ± 0.4 and 12 ± 0.2 mg/g, respectively), and in Ougan (11.6 ± 0.1, 10.3 ± 0.1 mg/g, respectively). High synephrine levels were found in Zhuhong (22.5 ± 1.4 mg/g) and Manju (17.6 ± 0.3 mg/g). The limonoid content varied from 104.54 to 1128.13 μg/g with the highest amounts in Manju. The extractable phenolic acids (free and ester form) were more prevalent than the bound forms. Ferulic and caffeic acids were predominate in both the extractable and bound phenolics. The TPC were in order from high to low: Zhuhong > Bendizao Wenzhang Satuma > Ponkan > Manju > Ougan > Shantian Satuma > Gongchuan Satuma > Rinan No. 1 Satuma. The antioxidant capacity followed a very similar trend when assayed by the FRAP, DPPH, and ABTS procedures. The results showed that the dropped fruit from super early to medium mature Satsuma, a world famous mandarin variety, contained relatively lower bioactive substances than the other local varieties. The results also suggest that the dropped mandarin fruit, especially the local varieties such as Zhuhong, Bendizao, Ougan, Manju, and Ponkan, could serve as a good source of extractable nutraceuticals and to serve as a raw material source for crude TCM.

The Chinese traditional dry-cured grass carp fish (Layú) was processed with (A) and without (B) sucrose. Higher levels of free amino acids (FAA) and biogenic amines were detected in the final products when compared to the fresh fish. In the presence of sucrose, Layú A had higher total free amino acids (39.9 g/kg DW) but lower total biogenic amines (112.5 mg/kg DW) than those in Layú B (35.4 g/kg DW and 143.7 mg/kg DW, respectively) after ageing. After 60 days, the products storaged at 4 °C had lower amount biogenic amines (Layú A: 112.2~579.5; Layú B: 144~593.8 mg/kg DW) than those at 20 °C (Layú A: 112.2~974.8; Layú B: 144~773.4 mg/kg DW), indicating that low temperature storage was a safer procedure.

The effects of factors and kinetics of all-trans-β-carotene degradation under ultrasound treatment in a model system were investigated. The compounds of degradation were also tentatively identified by HPLC-DAD, Raman and FT-IR spectroscopy. The type of solvents and temperature were important factors in determining the degradation reaction. Liquid height, ultrasonic intensity and duty cycle of ultrasound exposure only affected the rate of degradation but did not change the nature of degradation. Degradation rate of β-carotene in dichloromethane was the highest. Degradation rate of β-carotene decreased with increasing of temperature. Degradation kinetics of all-trans-β-carotene under ultrasound fitted first-order reaction at −5 to 15 °C, and fitted second-order reaction at 25 °C. Degradation products included isomers: 15-cis-β-carotene, di-cis-β-carotene and other compounds with function group of C–O.

In this study, power high intensity ultrasound was used to treat the gelatinized maize starch dispersions. To investigate the effects of ultrasound treatment on the properties of the film-forming dispersions and their resulting films, the apparent viscosity, solubility, morphology of the film-forming dispersions and the opacity, water vapor permeability, mechanical properties, X-ray diffraction of the films formed from these dispersions were tested. It was found that gelatinized maize starch dispersions treated by ultrasound for a certain period of time has a drastic decrease in viscosity, and a distinct increase in solubility. Microscopic observation shows distinctly rapture of ghost fragments in the dispersion with prolonged treatment time. It was also found that ultrasound treatment produces an excellent film with good transparency, improved moisture resistance and stronger structure.

Ultrasound-assisted extraction (UAE) has been widely applied in the extraction of a variety of biologically active compounds including phenolic compounds. However, there is an insufficiency of information on simultaneous extraction of these compounds in this area. In the present study, seven phenolic compounds of two families including cinnamic acids (caffeic, p-coumaric, ferulic, sinapic acid), and benzoic acids (protocatechuic, p-hydroxybenzoic, vanillic acid) from citrus (Citrus unshiuMarc) peels were evaluated by UAE. The effects of ultrasonic variables including extraction time, temperature, and ultrasonic power on the yields of seven phenolic acids was investigated. Results showed that the yields of phenolic compounds increased with both ultrasonic time and temperature increased, whereas the opposite occurred with increasing time at higher temperature to some certain. In the case of 40 °C, the decrease in the yields of some phenolic compounds was observed with increased time, whereas those of other compounds did not significantly declined. Ultrasonic power has a positive effect on the yields of phenolic acids under study. Among all ultrasound variables, temperature is the most sensitive on stability of phenolic compounds. Moreover, when phenolic compounds from citrus peel extracts were subjected to ultrasound process, the benzoic acids were more stable than the cinnamic acids. Meanwhile, the optimal ultrasound condition was different one compound from another. These were partly attributed to both the differently chemical structures of phenolic acids and the combination effects of ultrasonic variables.

Five cultivars of Myrica rubra, Biqi, Wandao, Dongkui, Dingao, and Zaodamei, were collected to analyze the phenolic compounds and evaluate the antioxidant properties of bayberry pomaces. The main anthocyanin was cyanidin-3-o-glucoside (3073.3–6219.2 mg/kg dry weight (DW)) and the main flavonol was quercetin-3-o-glucoside (296.2–907.9 mg/kg dry weight). Quercetin and myricetin were also found in the bayberry pomaces, and quercetin deoxyhexoside and myricetin deoxyhexoside were tentatively identified. The dominant phenolic acids were gallic acid (102.9–241.7 mg/kg dry weight) and protocatechuic acid (29.5–57.2 mg/kg dry weight). Other phenolic acids such as p-hydroxybenzoic, vanillic, caffeic, p-coumaric, and ferulic acids were also present in the bayberry pomaces, whereas, chlorogenic acid was only detected in Dongkui (1.58 mg/kg dry weight). The antioxidant activity of Wandao was the strongest of the five cultivars, whereas the activity of Dongkui was the weakest, and a significant positive relationship was observed between antioxidant activity and total phenolic content or total anthocyanins.

Bayberry (Myrica rubra Sieb. et Zucc.) kernel protein isolate (BKPI) was isolated from bayberry kernel defatted flour (BKDF) by isoelectric precipitation. BKPI was evaluated for chemical composition and selected functional properties with defatted kernel flour as reference. BKPI contained over 90% dry weight (DW) of protein versus 60.5% DW of protein in BKDF. It possessed a well-balanced amino acid composition according to the FAO/WHO reference except for a low content of lysine. BKPI had a solubility profile similar to that of BKDF, with minimum solubility observed at pH 4.0 and maximum solubility at pH 12.0. BKPI exhibited minimum foaming capacity (FC) (31.1%) and maximum foaming stability (FS) (72.7%) at pH 4.0. Minimum emulsifying capacity (EC) and emulsifying stability (ES) of BKPI and BKDF were observed at pH 4.0. BKPI had a least gelation concentration of (LGC) of 6% (w/v) at pH 4.0. Results indicated that bayberry kernel has potential to be exploited as a new protein source in China.

Phenolic compounds and antioxidant capacities of bayberry juices from 14 cultivars were investigated. HPLC–DAD and Folin-Ciocalteu methods were used for the analysis of the phenolic compounds. Biqi had the highest content of total flavonols (56.75 ± 4.68 mg/l), Wuzi had the highest content of phenolic acids (30.1 ± 0.05 mg/l), and Lizhizhong had the highest content of anthocyanins (514 ± 46.1 mg/l) and total phenolics (1055 ± 9.32 mg GAE/l). The FRAP and ABTS+ assay indicated that bayberry juices possessed considerable antioxidant activities, and all the analysed phenolic components contributed to the antioxidant capacities. The results also showed that bayberry juices from red coloured cultivars possessed higher contents of phenolic compounds than those from white coloured cultivars. The higher antioxidant capacities of red bayberry juices implied that they might be potential resources for the development of functional drinks.

Juices from fifteen citrus varieties (seven mandarins, four sweet oranges, one lemon, one grapefruit, and two pummeloes) of China were investigated mainly on quality parameters, total carotenoid, phenolic compounds (total phenolics, flavanone glycosides (FGs), and phenolic acids), and antioxidant capacity (ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay). Among the fifteen varieties, Bendizao had the highest content of total carotenoid (10.02 mg/L), Satsuma had the highest content of narirutin (288.12 mg/L), Yinzaocheng had the highest content of hesperidin (533.64 mg/L), and Huyou had the highest content of naringin (348.53 mg/L), neohesperidin (265.25 mg/L) and total FGs (746.08 mg/L). As for total phenolic acids, Liubencheng had the highest content (72.61 mg/L). Hybrid 439 achieved the highest AA content (631.25 mg/L), and the highest total phenolics (1555.49 mg/L) and the greatest inhibition of DPPH radical (61.62%). Hamlin had the highest ascorbic acid equivalent antioxidant capacity (AEAC: 899.31 mg/L) determined by FRAP assay. Correlation coefficients of AA, total phenolics (gallic acid equivalent), FRAP (AEAC), DPPH (I%), total FGs and total phenolic acids indicated that AA played a major role for the antioxidant capacity of citrus juices, and phenolics also played an important role, which may be mainly ascribed to FGs, whilst phenolic acids seemed to play a minimal role. Furthermore, Huyou and Hybrid 439 were considered two valuable varieties from the view of antioxidant capacity and nutrition.

Phenolic acids in potherb mustard (Brassica juncea, Coss.) were determined and the effects of pickling methods on the contents of total free phenolic acids, total phenolic acids, total phenolics, and antioxidant activities were investigated. Gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid were identified in the present study. The contents of total free phenolic acids, total phenolic acids and total phenolics in fresh potherb mustard were 84.8 ± 0.58 μg/g dry weight (DW), 539 ± 1.36 μg/g DW, and 7.95 ± 0.28 mg/g DW, respectively. The total free phenolic acids increased during the pickling processes, but the total phenolic acids, total phenolics, and antioxidant activities decreased. However, after 5 weeks of fermentation, all the pickling methods retained over 70% of total phenolic contents and above 65% of antioxidant capacities. The results indicated that pickling processes were relatively good methods for the preservation of phenolic acids and antioxidants for potherb mustard.

Composition and distribution of phenolic acids in Ponkan (Citrus poonensis Hort. ex Tanaka) and Huyou (Citrus paradisi Macf. Changshanhuyou) during maturity was investigated comprehensively in this study. High-performance liquid chromatography (HPLC) coupled with photodiode array (PDA) detector method was developed to separate and quantify protocatechuic, p-hydroxybenzoic, vanillic, caffeic, p-coumaric, ferulic, sinapic, and chlorogenic. For all of the phenolic acids, detection limits were about 0.01 μg/mL. Repeatability was 0.57–2.99% (relative standard deviation, RSD) for intraday and recovery ranged from 80.23% to 114.53%. In this study, phenolic acids were divided into four fractions: free, ester, glycoside and ester-bound. Generally, in each fraction, Ponkan had higher content of phenolic acids than Huyou, and with maturity there was a sharp decrease of them in both varieties, also peel contained more of them than flesh. Furthermore, chlorogenic acid and ferulic acid were the highest among the eight quantified phenolic acids, and content of caffeic acid was rather high at unripe stage, and hydroxycinnamic acids accounted for a larger portion compared with hydroxybenzoic acids especially for Ponkan. The total content of phenolic acids ranged from 180 μg/g DW (flesh of Huyou at ripe stage) to 5060 μg/g DW (peel of Ponkan at unripe stage). The data obtained here can be potentially used for discriminating the adulteration of citrus juices and may be useful for consumers and food technologists.

Volatile components of Fuzhou Yulu, a Chinese fish sauce, were analyzed by gas chromatography-mass spectrometry (GC-MS), and two pretreatment methods, i.e., purge and trap (P&T) GC-MS and ethyl acetate extraction followed by GC-MS, were compared. P&T-GC-MS method determined 12 components, including sulfur-containing constituents (such as dimethyl disulfide), nitrogen-containing constituents (such as pyrazine derivatives), aldehydes and ketones. Ethyl acetate extraction followed by GC-MS method detected 10 components, which were mainly volatile organic acids (such as benzenepropanoic acid) and esters. Neither of the two methods detected alcohols or trimethylamine. This study offers an important reference to determine volatile flavor components of traditional fish sauce through modern analysis methods.

The effect of UV-C treatments (0.75, 1.5 and 3.0 kJ/m2) on fruit quality, phenolic compounds and antioxidant capacity of minimally processed Satsuma mandarin during 12 days of storage at 4 °C was studied. The results showed that UV-C treatments had no adverse effects on quality attributes, ascorbic acid, phenolic acids and antioxidant capacity of mandarin segments. Significant increases of flavonoids (22.20% and 21.34% for narirutin, 11.75% and 33.25% for hesperidin) and total phenolics (5.73% and 8.13%) were found in 1.5 and 3.0 kJ/m2 UV-C treated fruit at 3 days of storage. Further study confirmed that the increase of flavonoids occurred during the first 3 days and diminished after 4 days of storage. UV-C dose at 3.0 kJ/m2 did not further improve the increase of flavonoids, and 0.75 kJ/m2 had no significant effects on phenolics. Proper application of UV-C treatment could be a new way to enhance the functional quality of minimally processed citrus fruit.Highlights► UV-C treatments retained quality attributes of minimally processed Satsuma mandarins. ► UV-C treatments increased flavonoids and total phenolics of mandarins during storage. ► UV-C did not affect antioxidant capacity and phenolic acids of mandarin segments.