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1.
Food Chem ; 305: 125454, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505413

RESUMO

The effects of the (-)-Epigallocatechin gallate (EGCG)-gelatin biofilm treatment (EGT) on microbial composition and quality of tilapia fillets stored at low temperatures were evaluated. The changes in mechanical properties, microbial reproduction, as well as lipid and protein oxidation during fillets storage were determined. The results showed that EGT reduced the microbial count and the relative abundance of the fillets. And EGT delayed the rate of lipid oxidation and protein denaturation in fillets. Compared with the control group, EGT samples had lower K values (74% on 18 d) and biogenic amines (39 mg/kg for putrescine and 50 mg/kg for cadaverine on 21 d). According to sensory evaluation, the shelf life of tilapia fillets was extended by 6 d in the EGT group. Therefore, EGT improved the quality of cryopreserved tilapia fillets and could be considered as a potential method for fish fillet preservation.

2.
Food Chem ; 305: 125477, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31610424

RESUMO

In recent years there is an increasing interest in dried fruits, although many of their nutritional components are readily lost during drying. The novelty of this paper was to assess the effect of hot-air drying (HAD) and far-infrared drying (FIRD) on the physicochemical properties and microstructure of mango slices pretreated with: control; 0.1% citric acid + 0.5% ascorbic acid + 0.5% CaCl2 + 1% NaCl; or 0.1% citric acid + 0.5% ascorbic acid + 0.5% CaCl2 + 1% NaCl + ultrasound treatments. Pretreatments resulted in a significant (p < 0.05) increase in reducing sugar, ascorbic acid and total phenol contents of dried samples. Moreover, compared with HAD, FIRD maintained a higher phenolic acid content, improved the nutrient retention and color attributes and better preserved microstructure. Therefore, pretreatments followed by FIRD is a potential method for obtaining high-quality dried mango slices.

3.
Food Chem ; : 125879, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31734012

RESUMO

Chlorogenic acid (CA) performs numerous bioactivities; however, its usage is currently limited because of low stability and poor bioaccessibility. In this study, a amylopectin-CA complex was formed. FTIR studies confirmed that the new complex formed via hydrogen and CH-π bonding, and was involved with the reorganization of the skeletal α-1,4 glucosidic linkages of amylopectin. DSC and XRD studies suggested that complexation affected starch crystallinity and increased the size of the amorphous region. Under high temperature, complex degradation followed first-order reaction kinetics whereas under low acidity, the complex retained maximum CA content at pH 2.5. In vitro gastrointestinal (GI) digestion studies showed that maximum digestion of the complex took place during the gastric phase (39%). In addition, 81.14% of the retained CA was absorbed after GI digestion. In conclusion, amylopectin complexation may improve the stability of CA during digestion and under various food-processing operations.

4.
Food Funct ; 10(12): 8081-8093, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31735943

RESUMO

Pectin oligosaccharides (POSs) can not only be used as prebiotics to promote the growth of beneficial bacteria in the intestine but also can be used as natural food-borne antiglycation agents to inhibit the formation of advanced glycation end products (AGEs) in vitro, which is related to their structure, including molecular weight and galacturonic acid content. In this study, haw polysaccharides (HPSs) were isolated and purified, and POSs with high antiglycation activity in vitro were prepared. On this basis, the inhibitory effect of POSs on the formation of AGEs in infant formula milk powder was investigated. The results showed that no obvious inhibitory effect of POSs was found on the formation of AGEs in infant formula milk powder under accelerated storage at 25 °C and 45 °C. But, POSs showed a strong inhibitory effect on the formation of furosine, Nε-carboxymethyllysine (CML), Nε-carboxyethyllysine (CEL) and the total AGEs in infant formula milk powder under accelerated storage at 65 °C. In addition, POSs also had a strong inhibitory effect on the formation of lipid oxidation products but did not affect the formation of protein degradation products. Simultaneously, the cytotoxicity experiments using human umbilical vein endothelial cells showed that the infant formula milk powder supplemented with POSs had the lowest cytotoxicity compared to the blank control (BC) and GOS/FOS supplementation milk powder under accelerated storage at 65 °C, which may be related to the inhibitory effect of POSs on the formation of AGEs in infant formula milk powder. Furthermore, the in vitro fermentation experiments showed that the antiglycation process did not affect the prebiotic activity of POSs in infant formula milk powder.

5.
J Food Biochem ; : e13073, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31637748

RESUMO

To obtain better qualities of litchi fruits, fruit pulps were subjected to ultrasonic treatment (UT) followed by drying. Samples were subjected to UT at 3 W/g for 10 min with distilled or ice water and compared with non-UT dried samples. After drying, vitamin C, total phenolic content, color, texture, nutrition, microbial load, drying kinetics, and shelf life were assessed. Results suggest that shear stress plus increasing heat reduced drying time by about 50%, and retained 70% vitamin C and 60% total phenolic content. UT led to about 75% of vitamin C and 70% total phenolic content through inhibition of ultrasonic heat. No significant differences were found in redness, yellowness, and hardness. Inhibition of ultrasound heat resulted in about 27% glucose, 22% fructose, 17% sucrose, and prolonged storage time. Inhibition of increasing ultrasound heat allows low drying cost and high product quality of litchi fruit in air-drying. PRACTICAL APPLICATIONS: UT promotes drying efficiency and preserves product quality. However, this treatment triggers the loss of antioxidants and sugars of litchi fruits when water temperature arises in the treatment. Additional use of ice crystals can offset the thermal effect of the UT; this mechanism reduces the diffusion and loss of nutrients from the material to the solution. This strategy is simple and feasible to improve the drying rate and to retain the content of antioxidants, and further improve the flavor and storage quality of dried litchi fruits.

6.
J Food Biochem ; 43(8): e12865, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31368569

RESUMO

This study aims to investigate the technological properties of yeast strains isolated from traditional low-salt fermented Suan yu fish as starter culture. A step-by-step approach was used to determine the technological properties of the isolated yeast strains. The enzymatic activity (catalase, urease, ß-glucosidase, protease, and lipase) under adverse conditions (pH, salt, and temperature) were evaluated. Principal component analysis was used to assess data. Twenty-five strains with desirable technological properties were selected for evaluation of probiotic traits (tolerance at pH 2.5 and 0.3% bile salts, antimicrobial activity, hydrophobic properties, and biofilm production). These isolates were identified by sequencing the D1/D2 region of 26S rDNA. Finally, seven isolates with desirable probiotic traits were analyzed for their ability to survive through gastric transit using a gastrointestinal simulation model. An In vitro test showed that isolates 3, 12, 19, 24, and 43 exhibited high survival levels (60%-70%), similar to those of the indicator strain (Saccharomyces cerevisiae). The results suggest that five isolates (S. cerevisiae strains 3, 12, 19, 24, and 43) showed desirable technological properties and probiotic traits and therefore can be used as functional starter cultures to produce fermented fish products. PRACTICAL APPLICATIONS: Researchers have investigated the activity of LAB as functional and probiotic microorganisms; however, information on the probiotic potential of yeasts remains limited. Yeasts are microorganisms that present and induce biochemical changes in several fermented meat and fish products. In the present study, the technological and probiotic properties of 52 isolates from Suan yu were investigated to identify potential probiotic strains for starter cultures. Our results suggest that five isolated S. cerevisiae strains showed desirable technological properties and probiotic traits and therefore can be used as functional starter cultures to produce fermented fish products, and other fermented foods. Functional yeast isolates are used to effectively improve the quality of fermented fish products for consumer acceptance. This study has focused on the possibility to produce a functional Suan yu using a potential probiotic S. cerevisiae as starter culture to enhance health benefits.

7.
Food Chem ; 299: 125108, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31310914

RESUMO

Macroporous resins have been employed in the effective recovery of flavonoids from plants. In this study, S8 polar resins were used to recover flavonoids and procyanidins from lotus seedpods. Adsorption kinetics, isotherms, and thermodynamics studies revealed that the adsorption process involved physico-chemical interactions, including flavonoid-resin and flavonoid-flavonoid electrostatic interactions, π-π aromatic stacking, moderate and strong hydrogen bonding, and repulsive forces. These forces worked complementarily in adsorption, except for the repulsive force, which opposed the adsorption. Further, adsorption temperature determined the adsorption behavior, with multilayer adsorption enhancing adsorption capacity. In dynamic desorption tests, an acetone/water/acetic acid mixture (58.77: 39.34: 1.89) designed by the D-optimal design method was able to desorb 95.57% and 89.85% of total flavonoids and procyanidins, respectively, using less than two bed volumes of solvent. Ultra-performance liquid chromatography triple-time of flight/mass spectrometry (UPLC-TOF/MS) analysis showed that 26 flavonoids, including 5 procyanidins, were detected after the recovery.


Assuntos
Flavonoides/isolamento & purificação , Nelumbo/química , Resinas Sintéticas/química , Sementes/química , Adsorção , Cromatografia Líquida de Alta Pressão/métodos , Flavonoides/análise , Flavonoides/química , Ligações de Hidrogênio , Espectrometria de Massas , Proantocianidinas/análise , Proantocianidinas/química , Proantocianidinas/isolamento & purificação , Eletricidade Estática
8.
Food Chem ; 297: 124993, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253336

RESUMO

Ultrasonic effect on extraction of cyanidin-3-galactoside (Cy3-gal) from pear fruit peel was investigated and compared with conventional extraction (CE) method. Different process factors were tested to determine the optimum conditions for ultrasonic-assisted extraction (UAE). Results revealed that under optimized UAE conditions (ultrasonic power = 162 W, temperature = 71 °C, trifluoroacetic acid = 3%, ethanol = 57%, ultrasonication time = 11 min, and sample to solvent ratio = 1:30 g/ml), Cy3-gal yield was significantly higher (0.34 3±â€¯0.005 mg/g) than from CE (0.266 ±â€¯0.004 mg/g), whereas the extract viscosity during UAE showed a negative impact. UPLC-Triple-TOF/MS analysis detected a total number of 13 anthocyanin compounds, out of which 8 were identified and that mainly consisted of cyanidin, delphinidin and petunidin compounds. Higher yield of Cy3-gal under UAE compared to CE was also justified by higher deformations in the cell structure. The possible mechanism of ultrasonication effect during the extraction process is also proposed in the present study. During scale-up UAE process, the extraction yield of Cy3-gal was recorded higher under batch scale-up compared to continuous operation. The present study is an attempt to optimize UAE of valuable anthocyanins from Pyrus communis 'Starkrimson' fruit peel and further scaled-up for higher volume extraction which can be utilized for industrial applications.


Assuntos
Antocianinas/isolamento & purificação , Extratos Vegetais/química , Pyrus/química , Sonicação/métodos , Antocianinas/análise , Antioxidantes/química , Cromatografia Líquida de Alta Pressão , Frutas/química , Frutas/metabolismo , Glucosídeos/análise , Glucosídeos/isolamento & purificação , Pyrus/metabolismo , Solventes/química , Espectrometria de Massas por Ionização por Electrospray , Temperatura Ambiente , Viscosidade
9.
Food Chem ; 297: 124910, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253292

RESUMO

Polyphenols can inhibit the enzymatic browning in food, but their indistinct synergistic effect and conformational change have limited their applications. In this paper, the mixture of quercetin, cinnamic acid and ferulic acid (Group 11, KI = 0.239 mM) possessed a higher inhibition ability than quercetin (KI = 0.361 mM), which could promote the spontaneous binding process. The final Group 11-tyrosinase complex is more stable, and the hydrophobic effect is the major driving force during the binding process. Moreover, there is not a direct relationship between the destruction of secondary structures and catalytic activity of tyrosinase. The interaction between ferulic acid and tyrosinase could destroy the secondary structures of enzyme but it had little impact on the tyrosinase activity. Molecular docking suggested that three polyphenols from Group 11 have synergistic effect on tyrosinase. This study provides new perspectives about the development of tyrosinase inhibitors in food products.


Assuntos
Inibidores Enzimáticos/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Polifenóis/química , Sítios de Ligação , Cinamatos/química , Cinamatos/metabolismo , Ácidos Cumáricos/química , Ácidos Cumáricos/metabolismo , Inibidores Enzimáticos/metabolismo , Cinética , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase/metabolismo , Estrutura Secundária de Proteína , Termodinâmica
10.
Anal Chim Acta ; 1058: 136-145, 2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-30851847

RESUMO

Based on conjugate addition-cyclization reaction of Cys with acrylate and subsequent 1,6-elimination of p-hydroxybenzyl moiety, a novel colorimetric and ratiometric fluorescent probe 1 was designed and synthesized. Upon addition of Cys to the solution of 1, the absorption spectra changed from 508 nm to 452 nm (Δ56 nm) and afforded visible color change from pink to yellow. Meanwhile, the emission spectra shifted from 644 nm to 539 nm (Δ105 nm) with remarkable changes in the emission ratio of F539 nm/F644 nm (R/R0 up to 760-fold), accompanying with an obvious fluorescence change from orange to green under illumination with a 365 nm UV lamp. In addition, 1 exhibited a large Stokes shift (136 nm), high sensitivity (detection limit of 46.7 nM), and excellent selectivity to Cys over Hcy and GSH. Moreover, 1 can discriminate Cys from Hcy and GSH by fluorescence spectra, even obvious visible and fluorescence color changes. Importantly, 1 can be used to image Cys in living cells by dual emission channels.


Assuntos
Acrilatos/química , Cumarínicos/química , Cisteína/análise , Corantes Fluorescentes/química , Acrilatos/síntese química , Acrilatos/toxicidade , Colorimetria/métodos , Cumarínicos/síntese química , Cumarínicos/toxicidade , Ciclização , Cisteína/química , Fluorescência , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HeLa , Humanos , Limite de Detecção , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos
11.
Molecules ; 24(5)2019 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-30841628

RESUMO

Supercritical fluid carbon dioxide (SF-CO2) was used to extract oil from Elaeagnus mollis Diels (E. mollis Diels) seed and its antioxidant ability was also investigated. The effect of extraction pressure (20⁻35 MPa), extraction temperature (35⁻65 C), extraction time (90⁻180 min) and seed particle size (40⁻100 mesh) on the oil yield were studied. An orthogonal experiment was conducted to determine the best operating conditions for the maximum extraction oil yield. Based on the optimum conditions, the maximum yield reached 29.35% at 30 MPa, 50 C, 150 min, 80 mesh seed particle size and 40 g/min SF-CO2 flow rate. The E. mollis Diels seed (EDS) oil obtained under optimal SF-CO2 extraction conditions had higher unsaturated fatty acid content (91.89%), higher vitamin E content (96.24 ± 3.01 mg/100 g) and higher total phytosterols content (364.34 ± 4.86 mg/100 g) than that extracted by Soxhlet extraction (SE) and cold pressing (CP) methods. The antioxidant activity of the EDS oil was measured by DPPH and hydroxyl radical scavenging test. EDS oil extracted by different methods exhibited a dose-dependent antioxidant ability, with IC50 values of no significant differences. Based on the results of correlation between bioactive compounds, lupeol and -tocopherol was the most important antioxidant in EDS oil.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Dióxido de Carbono/química , Elaeagnaceae/química , Óleos Vegetais/química , Óleos Vegetais/farmacologia , Sementes/química , Ácidos Graxos/química , Tocoferóis/química , Tocotrienóis/química
12.
Food Chem ; 283: 59-67, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30722916

RESUMO

Purple sweet potatoes are known for its vibrant purple color due to high level of anthocyanins. A polyethylene glycol based ultrasonic-assisted green extraction (PEG-UAE) of anthocyanins from purple sweet potato was proposed. Different types of PEG were tested for anthocyanin extraction along with PEG concentration, liquid-to-solid ratio, ultrasonic temperature and time were investigated for its impact on viscosity and extraction efficiency. The optimum extraction condition, 42 mL/g of ratio, 83% of PEG 200 concentration, 64 °C of ultrasonic temperature and 80 min of sonication time, resulted in better extraction of anthocyanins (83.78 mg CE/100 g DW) and phenolics (994.88 mg GAE/100 g DW). Using UPLC-Triple-TOF/MS, ten anthocyanin and six non-anthocyanin compounds were identified and characterized, with the highest peak area for cyanidin-3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside (25.9%). Moreover, the anthocyanins and phenolics extraction yield along with antioxidant activity were negatively correlated with PEG viscosity, on which ultrasonication has profound effects.


Assuntos
Antocianinas/isolamento & purificação , Ipomoea batatas/química , Polietilenoglicóis/química , Ultrassom/métodos , Cromatografia Líquida de Alta Pressão/métodos , Química Verde , Sonicação/métodos , Viscosidade
13.
J Agric Food Chem ; 67(1): 352-363, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30541284

RESUMO

Soluble acid invertases (SAIs) cleave sucrose into hexose in vacuoles and play important roles in influencing fruit quality. However, their potential roles in regulating sugar composition and the "sugar receding" process of longan fruits lacked systematic investigations. Our results showed that sucrose/hexose ratios and sugar receding rates of longan pulp varied among cultivars. Analysis of enzymes for sucrose synthesis and cleavage indicated that DlSAI showed the highest negative correlation with sucrose/hexose ratio at both of activity and expression level. Moreover, high SAI activity and DlSAI expression resulted in extremely low sucrose/hexose ratio in 'Luosanmu' longan from development to mature stages and a remarkable loss of sugar in 'Shixia' longan fruits during on-tree preservation. In conclusion, DlSAIs act as key factors influencing sucrose/hexose ratio and sugar receding through transcriptional and enzymatic regulations. These results might help improve the quality of on-tree preserved longan.


Assuntos
Glicosídeo Hidrolases/metabolismo , Hexoses/metabolismo , Proteínas de Plantas/metabolismo , Sapindaceae/enzimologia , Sacarose/metabolismo , Frutas/química , Frutas/enzimologia , Frutas/genética , Frutas/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Hexoses/química , Cinética , Proteínas de Plantas/química , Proteínas de Plantas/genética , Sapindaceae/química , Sapindaceae/genética , Sapindaceae/metabolismo , Sacarose/química
14.
Chem Cent J ; 12(1): 30, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29541871

RESUMO

BACKGROUND: Preservative effect of melanin-free extract of Sepia esculenta ink (MFESI) on Sparus latus fillet has been verified in our previous work. This study aims to further approach the mechanism of MFESI for extending the shelf-life of fish fillet during cold storage. Tilapia fillets were treated with different dosage of MFESI (0, 15, 25 and 35 mg/ml) and packed with preservative film for succedent cold-storage at 4 °C for scheduled time. Contents of total volatile basic nitrogen and sulfydryl and carbanyl groups were measured for evaluating protein oxidation. Malondialdehyde contents were measured for estimating lipid peroxidation and loss of water was used to determine water-holding capacity of fillet. RESULTS: The data indicated that MFESI not only possessed certain degree of antioxidant capacity in vitro, also lengthened shelf-life of tilapia fillet in cold-storage condition. Apart from 15 mg/ml, both 25 and 35 mg/ml of MFESI obviously prevented lipid and protein from oxidation and reduced loss of water from tilapia fillets, and the latter was more effective than the former. CONCLUSION: MFESI can repress lipid peroxidation and protein oxidation and reduce water loss, maintain the tilapia fillets quality and, thus, it could be an effective and natural preservative for extending the shelf-life of tilapia fillets during cold storage.

15.
Biotechnol Lett ; 40(1): 173-179, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29038926

RESUMO

OBJECTIVE: To explore deactivation kinetics and the effects of some additives on the activity and conformational changes of D-psicose 3-epimerase (DPEase) during its storage. RESULTS: The experimental data of DPEase inactivation during storage at 4-45 °C fitted with the first-order expression model. The inactivation rate constants of DPEase stored at 4, 10, 25, 35 and 45 °C were 0.0076, 0.01, 0.0223, 0.0351 and 0.0605 day, respectively. A regression formula of half-lives as storage temperatures, ln t 1/2 = 4.7396/T × 103 - 12.536, was obtained. MnSO4 at 0.15 g l-1 enhanced the residual activity by 16% after 15 days and 17% after 30 days compared with control, but 2 g ascorbic acid l-1 reduced activity by 69 and 58% at the same time. In addition, 0.15 g MnSO4 l-1 and 20 g ethylene glycol l-1 maintained the secondary and tertiary structure of DPEase. CONCLUSIONS: MnSO4 and ethylene glycol actively promoted the storage and conformational stability of DPEase. In contrast, ascorbic acid was disadvantageous.


Assuntos
Carboidratos Epimerases/química , Carboidratos Epimerases/metabolismo , Estabilidade Enzimática , Ácido Ascórbico/metabolismo , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Ativadores de Enzimas/metabolismo , Inibidores Enzimáticos/metabolismo , Etilenoglicol/metabolismo , Compostos de Manganês/metabolismo , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Sulfatos/metabolismo , Temperatura Ambiente
16.
Exp Ther Med ; 14(6): 5889-5895, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29285137

RESUMO

The aim of this study was to determine the mechanisms driving the protective effects of squid ink polysaccharide (SIP) against cyclophosphamide (CP)-induced testicular damage, focusing on germ cells. In the testes of mice exposed to CP and/or SIP, the present study examined the levels of reactive oxygen species (ROS) and malondialdehyde, activity of superoxide dismutase levels, protein expression levels of B-cell lymphoma 2 (Bcl2), Bcl2-associated X protein (Bax), and total Caspase 3, activation of p-p38 and p-Akt proteins, and tissue morphology. The findings indicated that CP induced ROS production and oxidative stress, resulting in testicular damage. However, under administration of SIP, oxidative stress was impaired and the testicular toxicity induced by CP was weakened, which implied that SIP may have an important role in preventing chemotherapeutic damage to the male reproductive system via promoting antioxidant ability. Furthermore, the altered expression levels, including the upregulation of Bax and Caspase 3, downregulation of Bcl-2 and the increased Bax/Bcl-2 ratio, indicated that apoptosis occurred in CP exposed testes of mice; however, the alterations were reversed in mice treated with SIP. Moreover, in CP-exposed testes, p38 and Akt proteins were significantly phosphorylated (P<0.05), whereas in the testes of mice co-treated with SIP and CP, phosphorylation of the two proteins was inhibited, demonstrating that the two signalling pathways participated in the regulative processes of the deleterious effects caused by CP, and the preventive effects SIP mediated.

17.
Int J Mol Sci ; 18(12)2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29236044

RESUMO

This paper investigated the effects of guar gum with sorbitol coating on the oil absorption of French fries by combined dye oil methods, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The results showed that pretreatment of blanching with calcium ions and coating with guar gum and sorbitol could significantly reduce the structural oil (STO) and penetrated surface oil (PSO) of French fries and have no negative effects on its texture and also effectively control the final moisture content (p < 0.05). Compared with control or samples coated with guar gum (blanching with or without calcium ions), the total oil (TO) of French fries with guar gum and sorbitol reduced by 50.8%, 33.1% and 30.6%, respectively. CLSM photographs confirmed that STO significantly reduced after coating with guar gum and sorbitol, followed by PSO. In the process of frying, the coatings of guar gum or guar gum with sorbitol could effectively prevent oil from infiltrating the potato tissue, which can be seen in the SEM photographs. The barrier properties of French fries were enhanced by coating guar gum, and sorbitol was added to avoid pores and cracks. Blanching with calcium ion can significantly reduce the final moisture content of coating French fries.


Assuntos
Culinária/métodos , Galactanos/química , Mananas/química , Óleo de Palmeira/química , Gomas Vegetais/química , Solanum tuberosum/química , Sorbitol/química , Adsorção , Cálcio/química , Cor , Microscopia Confocal , Microscopia Eletrônica de Varredura , Óleo de Palmeira/análise
18.
Carbohydr Polym ; 163: 270-279, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28267506

RESUMO

In our recent reports, a squid ink polysaccharide (SIP) was found having preventive activity against cyclophosphamide induced damage in mouse testis and ovary. Here we further reveal the regulative mechanism of SIP against chemical toxicity on testis. Leydig cells exposed to acrolein (ACR) underwent apoptosis at 12h and 24h. Before apoptosis, cells occurred autophagy that was confirmed by high autophagic rate and Beclin-1 protein content at 3h. PI3K/Akt and p38 MAPK signal pathways involved in the regulatory mechanisms. These outcomes of ACR were recovered completely by SIP, which was demonstrated by attenuated disruption of redox equilibrium and increased testosterone production, through suppressing ACR-caused autophagy and apoptosis regulated by PI3K/Akt and p38 MAPK signal pathways in Leydig cells. Summarily, autophagy occurred before apoptosis caused by ACR-activated p38 MAPK and PI3K/Akt pathways were blocked by SIP, resulting in survival and functional maintenance of Leydig cells.


Assuntos
Apoptose , Autofagia , Glicosaminoglicanos/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Sepia/química , Acroleína , Animais , Células Cultivadas , Masculino , Camundongos , Transdução de Sinais
19.
Talanta ; 164: 154-158, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28107910

RESUMO

A sensitive indirect competitive nanobody-based enzyme linked immunosorbent assay (Nb-ELISA) for ochratoxin A (OTA) with high resistance to cereal matrix interference was developed. Nanobodies against OTA (Nb15, Nb28, Nb32, Nb36) were expressed in E. coli cells and their thermal stabilities were compared with that of an OTA-specific monoclonal antibody 6H8. All nanobodies could still retain their antigen-binding activity after exposure to temperature 95°C for 5min or to 90°C for 75min. Nb28 that exhibited the highest sensitivity in ELISA was selected for further research. An indirect competitive ELISA based on Nb28 was developed for OTA, with an IC50 of 0.64ng/mL and a linear range (IC20-IC80) of 0.27-1.47ng/mL. Cereal samples were analyzed following a 2.5 fold dilution of sample extracts, showing the good resistance to matrix interference of the Nb-ELSIA. The recovery of spiked cereal samples (rice, oats, barley) ranged from 80% to 105% and the Nb-ELISA results of OTA content in naturally contamined samples were in good agreement with those determined by a commercial ELISA kit. The results indicated the reliablity of nanobody as a promising immunoassay reagent for detection of mycotoxins in food matrix and its potential in biosensor development.


Assuntos
Técnicas Biossensoriais/métodos , Grão Comestível/química , Ensaio de Imunoadsorção Enzimática/métodos , Ocratoxinas/análise , Anticorpos de Domínio Único/imunologia , Contaminação de Alimentos/análise , Ocratoxinas/imunologia
20.
Int J Food Microbiol ; 242: 141-151, 2017 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-28011132

RESUMO

This study aimed to determine the predominant processing adaptability of 27 selected isolates of Staphylococcus xylosus in 'Suan yu', a traditional Chinese low-salt fermented whole-fish product. The isolates were screened for proteolytic, lipolytic, and enzymatic profiles; amino-acid decarboxylase content; antimicrobial activities; and tolerance to low temperatures, pH5.0, and salt. Two S. xylosus strains grew at 10°C in the presence of 10% NaCl and at pH5.0. Agar-plate assays and sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed that 21 and 8 of the strains exhibited appropriate proteolytic activities against myofibrillar and sarcoplasmic proteins, respectively. All S. xylosus strains also displayed different enzymatic profiles, and most strains showed negative decarboxylase activities. The results of this step were used as input data for a Principal Component Analysis; therefore, the most technologically relevant strain 3 and 8 were combined with L. plantarum 120 as MS1 and MS2, respectively, were further selected for the fermented fish surimi, and the fish surimi inoculated with mixed starter cultures (MS1, MS2) scored high for overall acceptability. Free amino acid contents of 1757 and 1765mg/100g sample were found in fish surimi inoculated with MS1 and MS2, respectively, after 72h of fermentation. Therefore, Sx-3 and Sx-8, which presented the best predominant processing adaptability, is an eligible starter culture for fermented fish production.


Assuntos
Produtos Pesqueiros/microbiologia , Staphylococcus/fisiologia , Adaptação Fisiológica , Aminoácidos/análise , Aminoácidos/metabolismo , Animais , China , Fermentação , Produtos Pesqueiros/análise , Peixes , Manipulação de Alimentos , Microbiologia de Alimentos , Cloreto de Sódio/análise , Cloreto de Sódio/metabolismo , Staphylococcus/classificação , Staphylococcus/genética , Staphylococcus/isolamento & purificação
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