Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
J Food Sci Technol ; 52(8): 5305-10, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26243957

RESUMO

A non-destructive method to analyze the freshness of raw milk was developed using a FT-NIR spectrometer and a fiber optic probe. Diffuse transmittance spectra were acquired in the spectral range 833 ~ 2,500 nm from raw milk samples collected from Northwest A&F University Animal Husbandry Station. After each spectral acquisition, quality parameters such as acidity, pH, and lactose content were measured by traditional detection methods. For all milk samples, PLS (partial least square regression), MLR (multiple linear regression), and ANN (artificial neural networks) analyses were carried out in order to develop models to predict parameters that were indicative of freshness. Predictive models showed R(2) values up to 0.9647, 0.9876 and 0.8772 for acidity, pH, and lactose content, respectively (validation set validations). The similarity analysis and classification between raw milk freshness during storage was also conducted by means of hierarchical cluster analysis. Over an 8 day storage period, the highest heterogeneity was evident between days 1 and 2.

2.
Food Chem ; 438: 138067, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38039865

RESUMO

In this study, figs were irradiated with X-rays doses of 1.0, 3.0, and 5.0 kGy and stored at 4 °C for 20 d to evaluate effects of X-ray on redox homeostasis and energy metabolism in figs. Non-irradiated figs were recorded as control group. Results indicated that 3.0 kGy X-rays delayed fig color discoloration by inhibiting the ΔE* values. The electrolyte leakage, MDA and O2-· levels of figs were significantly alleviated. Energy metabolism assay revealed that 3.0 kGy X-rays could significantly maintain higher activities of H+-ATPase, Ca2+-ATPase, SDH, CCO, G6PDH and 6PGDH of figs. 3.0 kGy X-rays also retained mitochondria membrane integrity of figs. Furthermore, 3.0 kGy X-rays resulted in 26.09 % higher NADK activity and 16.30 % lower NADH content than the control. The study proves that X-ray irradiation can be used as figs preservation means to maintain redox homeostasis and regulate energy metabolism, thus lengthening the shelf life of figs.


Assuntos
Ficus , Raios X , Oxirredução
3.
Foods ; 11(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36429139

RESUMO

This study investigated the impact of high pressure and temperature (HTHP) and electron-beam irradiations (3, 5, 7, and 9 kGy) using differences in two sterilization methods on the volatile compounds and sensory characteristics of cooked bacon. It showed that 7 and 9 kGy of irradiation caused a significant reduction in species of volatile compounds and sensory features, but the concentration of total ketones, alcohols, aldehydes, acids and aromatic hydrocarbons significantly increased at 9 kGy. Samples treated with a dose of less than 5 kGy did not change volatile compounds and sensory properties. High-temperature-high-pressure conditions could greatly impact the concentrations of volatile compound species and sensory traits. The electronic nose effectively detected the flavor difference in different sterilization methods. Fingerprinting showed that HTHP and 9-kGy-treated groups were significantly different from other treatments. This study inferred that 5 kGy might be optimal for maintaining the original flavor and sensory properties of cooked bacon.

4.
Food Chem ; 374: 131781, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-34896943

RESUMO

Thymol (TMO) was loaded into chitosan nanoparticles (CSNPs) to inhibit chestnuts decay during storage. Three chestnut treatments were evaluated, including the CK (uncoated control), CSNPs (coated with chitosan nanoparticles), and TMO-CSNPs (coated with thymol-loaded chitosan nanoparticles). Quality assessments of chestnuts were conducted periodically for up to 180 days, which included starch content, amylase activity, water content, respiration rate, weight loss rate, microbiological indicators, decay rate, and quality evaluation. Results indicated that TMO-CSNPs had significantly less nutrient loss in soluble sugar (10.61%) and starch content (27.72%) compared with CK, which was attributed to low metabolic activities as evident in low amylase activity and respiration rate. Moreover, TMO-CSNPs significantly inhibited the growth of mold and yeast (4.17 log CFU g-1 on day 180) and kept the lowest decay rate (5.33%). This study demonstrates the potential of food nanomaterial as an alternative strategy to promote food security and supply chain resilience.


Assuntos
Quitosana , Nanopartículas , Nanoestruturas , Antioxidantes , Timol
5.
Food Chem ; 285: 389-396, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30797361

RESUMO

This study aimed to reveal the physiological mechanism of resistance to postharvest blue mold of kiwifruit. Hongyang and Qihong kiwifruits were inoculated with Penicillium expansum (P. expansum) and stored at low temperature (0 ±â€¯1 °C). The disease incidence and lesion diameter, activities of defense-related enzymes, and contents of defense-related substance of Hongyang and Qihong kiwifruits were also compared, combined with the observation of fruit pericarp structure by scanning electron microscopy. Results showed that the disease resistance of Hongyang was stronger than that of Qihong with late onset, low incidence, and small lesion diameter. And Hongyang kiwifruit showed a high biochemical resistance after inoculation with P. expansum. The epidermis structure of Hongyang kiwifruit had typical disease resistance characteristics with a dense epidermis structure, orderly cell arrangement, and less obvious microcracks. The strong biochemical resistance, dense, and complete epidermis structure of Hongyang fundamentally guarantee its strong resistance to diseases.


Assuntos
Actinidia/microbiologia , Frutas/microbiologia , Penicillium/patogenicidade , Doenças das Plantas/microbiologia , Resistência à Doença , Enzimas/metabolismo , Microbiologia de Alimentos , Armazenamento de Alimentos , Especificidade da Espécie
6.
PLoS One ; 13(2): e0188869, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29451896

RESUMO

OBJECTIVE: Hypomyelinating disorders are a group of clinically and genetically heterogeneous diseases characterized by neurological deterioration with hypomyelination visible on brain MRI scans. This study was aimed to clarify the clinical and genetic features of HMDs in Chinese population. METHODS: 119 patients with hypomyelinating disorders in Chinese population were enrolled and evaluated based on their history, clinical manifestation, laboratory examinations, series of brain MRI with follow-up, genetic etiological tests including chromosomal analysis, multiplex ligation probe amplification, Sanger sequencing, targeted enrichment-based next-generation sequencing and whole exome sequencing. RESULTS: Clinical and genetic features of hypomyelinating disorders were revealed. Nine different hypomyelinating disorders were identified in 119 patients: Pelizaeus-Merzbacher disease (94, 79%), Pelizaeus-Merzbacher-like disease (10, 8%), hypomyelination with atrophy of the basal ganglia and cerebellum (3, 3%), GM1 gangliosidosis (5, 4%), GM2 gangliosidosis (3, 3%), trichothiodystrophy (1, 1%), Pol III-related leukodystrophy (1, 1%), hypomyelinating leukodystrophy type 9 (1, 1%), and chromosome 18q deletion syndrome (1, 1%). Of the sample, 94% (112/119) of the patients were genetically diagnosed, including 111 with mutations distributing across 9 genes including PLP1, GJC2, TUBB4A, GLB1, HEXA, HEXB, ERCC2, POLR3A, and RARS and 1 with mosaic chromosomal change of 46, XX,del(18)(q21.3)/46,XX,r(18)(p11.32q21.3)/45,XX,-18. Eighteen novel mutations were discovered. Mutations in POLR3A and RARS were first identified in Chinese patients with Pol III-related leukodystrophy and hypomyelinating leukodystrophy, respectively. SIGNIFICANCE: This is the first report on clinical and genetic features of hypomyelinating disorders with a large sample of patients in Chinese population, identifying 18 novel mutations especially mutations in POLR3A and RARS in Chinese patients, expanding clinical and genetic spectrums of hypomyelinating disorders.


Assuntos
Heterogeneidade Genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/epidemiologia , China/epidemiologia , Bandeamento Cromossômico , Feminino , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/diagnóstico por imagem , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Lactente , Recém-Nascido , Cariotipagem , Imageamento por Ressonância Magnética , Masculino
7.
J Agric Food Chem ; 63(6): 1863-8, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25594226

RESUMO

Preharvest calcium application has been shown to increase broccoli microgreen yield and extend shelf life. In this study, we investigated the effect of calcium application on its metabolome using ultra-high-performance liquid chromatography with mass spectrometry. The data collected were analyzed using principal component analysis and orthogonal projection to latent structural discriminate analysis. Chemical composition comparison shows that glucosinolates, a very important group of phytochemicals, are the major compounds enhanced by preharvest treatment with 10 mM calcium chloride (CaCl2). Aliphatic glucosinolates (glucoerucin, glucoiberin, glucoiberverin, glucoraphanin, pentyl glucosinolate, and hexyl glucosinolate) and indolic glucosinolates (glucobrassicin, neoglucobrassicin, and 4-hydroxyglucobrassicin) were increased significantly in the CaCl2 treated microgreens using metabolomic approaches. Targeted glucosinolate analysis using the ISO 9167-1 method was further employed to confirm the findings. Results indicate that glucosinolates can be considered as a class of compounds that are responsible for the difference between two groups and a higher glucosinolate level was found in CaCl2 treated groups at each time point after harvest in comparison with the control group.


Assuntos
Brassica/química , Brassica/efeitos dos fármacos , Cloreto de Cálcio/farmacologia , Glucosinolatos/análise , Cromatografia Líquida de Alta Pressão , Ácidos Cumáricos/análise , Espectrometria de Massas , Metabolômica
8.
Brain Dev ; 37(8): 797-802, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25491635

RESUMO

PURPOSE: Pelizaeus-Merzbacher disease (PMD) is a rare X-linked recessive hypomyelination disorder characterized by nystagmus, ataxia, impaired motor development, and progressive spasticity. Identification of proteolipid protein 1 (PLP1) mutations in Chinese patients with Pelizaeus-Merzbacher disease (PMD) and confirmation of the biological impacts of the identified mutations are the aims of this study. METHODS: An analysis of clinical materials and a follow-up study were conducted for the patients with PMD. Sequencing and immunofluorescence were applied for molecular analysis of the causative gene PLP1. RESULTS: We identified PLP1 mutations in seven male patients with PMD. Three novel missense mutations (c.353C>G, p.T118R; c.623G>T, p.G208V; c.709T>G, p.F237V) and three reported missense mutations (c.467C>T, p.T156I; c.517C>T, p.P173S; c.646C>T, p.P216S) of PLP1 were identified from seven Chinese PMD patients. The three mutations (F237V in patient 2, P216S in patient 5 and T156I in patient 6) were de novo. Mutant proteins were trapped in the lumen of endoplasmic reticulum. CONCLUSION: We have identified six pathogenic mutations, enriching the specific spectrum of missense mutations in the patients with PMD. The six PLP1 mutations are probably pathogenic. By reviewing the known PLP1 mutations, we have preliminarily revealed the position of missense mutation may be associated with the severity of PMD.


Assuntos
Povo Asiático/genética , Mutação de Sentido Incorreto , Proteína Proteolipídica de Mielina/genética , Doença de Pelizaeus-Merzbacher/genética , Criança , Pré-Escolar , China , Estudos de Associação Genética , Humanos , Lactente , Masculino , Proteína Proteolipídica de Mielina/metabolismo , Doença de Pelizaeus-Merzbacher/metabolismo , Doença de Pelizaeus-Merzbacher/patologia
9.
J Food Sci ; 77(5): S188-93, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-23163949

RESUMO

Edible flowers have great sensory appeal, but their extremely short shelf life limits their commercial usage. Postharvest 1-methylcyclopropene (1-MCP) treatment is used to counter ethylene activity and delay senescence in fresh produce; however, its potential application in edible flowers has not been tested. The objective of this study was to investigate the effect of 1-MCP treatment with modified atmosphere packaging (MAP) on the shelf life of edible flowers. Freshly harvested carnations and snapdragons were packaged in trays with or without 0.5 µL/L of 1-MCP, sealed with a gas permeable film, and stored at 5 °C. Package atmospheres, tissue electrolyte leakage, and flower quality were evaluated on days 0, 7, and 14. Treatment with 1-MCP resulted in significantly slower changes in package headspace O(2), CO(2), and C(2)H(4) partial pressures, maintained higher overall quality of both flower species and reduced electrolyte leakage and abscission in snapdragon. All samples prepared with MAP had significantly reduced dehydration and higher overall quality compared to flowers packaged commercially in plastic clamshell containers. Treatments with controlled release of 1-MCP and MAP significantly extended storage life of edible carnation and snapdragon flowers.


Assuntos
Ciclopropanos/farmacologia , Flores/química , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Antirrhinum/química , Dióxido de Carbono/análise , Dianthus/química , Etilenos/análise , Qualidade dos Alimentos , Armazenamento de Alimentos , Oxigênio/análise
10.
PLoS One ; 7(3): e33087, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22416245

RESUMO

Megalencephalic leukoencephalopathy with subcortical cysts (MLC, MIM# 604004) is an autosomal recessive inherited disease mostly resulting from MLC1 mutations. In this study, we finished the functional analysis of MLC1 mutations identified recently in Chinese patients, including five newly described missense mutations (R22Q, A32V, G73E, A275T, Y278H), one known nonsense mutation (Y198X), and two known missense mutations (S69L, T118M). We found MLC1(wt) was localized to the cell periphery, whereas mutant R22Q, A32V, G73E, S69L and T118M were trapped in the lumen of endoplasmic reticulum (ER) when we transfected the wild-type and mutant MLC1 in U373MG cells. Compared to wild type, the mutant G73E, T118M, Y198X and A275T transcript decreased and all mutants except R22Q had lower protein expression in transfected U373MG cells. Therefore, we propose that all these eight MLC1 mutations had functional effect either on their protein/mRNA expression, or on their intracellular protein localization, or both.


Assuntos
Códon sem Sentido , Cistos/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Povo Asiático/genética , Sequência de Bases , Western Blotting , Linhagem Celular Tumoral , China , Cistos/metabolismo , Análise Mutacional de DNA , Retículo Endoplasmático/metabolismo , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Microscopia Confocal , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA