Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Agric Food Chem ; 72(19): 11278-11291, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38708781

RESUMO

Moringa seeds are an excellent dietary source of phytochemicals (i.e., glucosinolates, GSLs; isothiocyanates, ITCs) with health-beneficial effects. Although numerous studies have been conducted on moringa seeds, the effect of germination on the regulation of GSLs remains scarcely explored. The present study investigated the dynamic changes of GSLs in moringa seeds during germination (at 25, 30, and 35 °C for 6 days in the dark) through an untargeted metabolomics approach and compared the antioxidant capacity of ungerminated and germinated moringa seeds. Our results showed that germination significantly increased the total GSL content from 150 (day 0) to 323 µmol/g (35 °C, day 6) on a dry weight (DW) basis, especially glucomoringin (GMG), the unique glucosinolate in moringa seeds, which was significantly upregulated from 61 (day 0) to 149 µmol/g DW (35 °C, day 4). The upregulation of GMG corresponded to the metabolism of tyrosine, which might be the initial precursor for the formation of GMG. In addition, germination enhanced the total ITC content from 85 (day 0) to 239 µmol SE/g DW (35 °C, day 6), indicating that germination may have also increased the activity of myrosinase. Furthermore, germination remarkably increased the total phenolic content (109-507 mg GAE/100 g DW) and antioxidant capacity of moringa seeds. Our findings suggest that moringa sprouts could be promoted as a novel food and/or ingredient rich in GMG.


Assuntos
Germinação , Glucosinolatos , Moringa , Sementes , Tirosina , Sementes/química , Sementes/metabolismo , Sementes/crescimento & desenvolvimento , Tirosina/metabolismo , Tirosina/análise , Moringa/química , Moringa/metabolismo , Moringa/crescimento & desenvolvimento , Glucosinolatos/metabolismo , Glucosinolatos/análise , Glucosinolatos/química , Antioxidantes/metabolismo , Antioxidantes/química , Antioxidantes/análise
2.
Int J Biol Macromol ; 265(Pt 2): 131398, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38599903

RESUMO

This research aimed to assess the effects of flaxseed mucilage (Mu) coatings supplemented with postbiotics (P) obtained from Lactobacillus acidophilus LA-5 on various physical, biochemical, and microbial characteristics of strawberry fruits. Strawberry fruits were immersed for 2 min in Mu2.5 (2.5 % mucilage in distilled water), Mu5 (5 % mucilage in distilled water), P-Mu2.5 (2.5 % mucilage in undiluted postbiotics) and P-Mu5 (5 % mucilage in undiluted postbiotics) solutions and were stored at 4 °C and 85 RH for 12 days. All coatings were effective in reducing fungal count compared to the uncoated control fruits. Mu5 coating exhibited the highest efficacy, reducing fungal count by 2.85 log10 CFU/g, followed by Mu2.5 (1.47 log10 CFU/g reduction) and P-Mu2.5 groups (0.90 log10 CFU/g reduction). The fruits coated with edible coatings showed significant delays in the change of weight loss, pH, and total soluble solids as compared to the uncoated fruits. The coating containing postbiotics i.e., P-Mu5 also showed a significant increase in the total phenolic contents, total flavonoid content, antioxidant capacity, and total anthocyanin content at the end of storage relative to the uncoated fruits. Thus, Mu and P-Mu coatings may be a useful approach to maintaining the postharvest quality of strawberry fruits during cold storage.


Assuntos
Linho , Fragaria , Conservação de Alimentos , Armazenamento de Alimentos , Fragaria/química , Polissacarídeos/farmacologia , Água/farmacologia
3.
Food Microbiol ; 121: 104525, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38637087

RESUMO

The lack of vitamin B12 in unprocessed plant-based foods can lead to health problems in strict vegetarians and vegans. The main aim of this study was to investigate the potential synergy of co-culturing Bifidobacterium animalis subsp. lactis and Propionibacterium freudenreichii in improving production of vitamin B12 and short-chain fatty acids in soy whey. Different strategies including mono-, sequential and simultaneous cultures were adopted. Growth, short-chain fatty acids and vitamin B12 were assessed throughout the fermentation while free amino acids, volatiles, and isoflavones were determined on the final day. P. freudenreichii monoculture grew well in soy whey, whereas B. lactis monoculture entered the death phase by day 4. Principal component analysis demonstrates that metabolic changes in both sequential cultures did not show drastic differences to those of P. freudenreichii monoculture. However, simultaneous culturing significantly improved vitamin B12, acetic acid and propionic acid contents (1.3 times, 5 times, 2.5 times, compared to the next highest treatment [sequential cultures]) in fermented soy whey relative to other culturing modes. Hence, co-culturing of P. freudenreichii and B. lactis would provide an alternative method to improve vitamin B12, acetic acid and propionic acid contents in fermented foods.


Assuntos
Bifidobacterium animalis , Propionibacterium freudenreichii , Propionatos , Propionibacterium freudenreichii/metabolismo , Bifidobacterium animalis/metabolismo , Soro do Leite , Vitamina B 12/análise , Vitamina B 12/metabolismo , Propionibacterium/metabolismo , Ácidos Graxos Voláteis/metabolismo , Fermentação , Ácido Acético/metabolismo , Proteínas do Soro do Leite/metabolismo , Vitaminas/metabolismo
4.
Foods ; 13(7)2024 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-38611297

RESUMO

This study investigated the changes in colour, amino acids, and volatile flavour compounds in the enzymatic hydrolysates of chicken carcasses containing different types and amounts of reducing sugars (xylose, arabinose, glucose, and fructose), so as to develop a chicken-based flavouring agent. Before heat treatment at 100 °C for 60 min, the chosen reducing sugars were separately added to the chicken carcass hydrolysate at its natural pH. Pentoses decreased pH more significantly than hexoses in the chicken carcass hydrolysate. The browning degree followed the pattern of pH decline, as pentoses caused more intense browning than hexoses, with xylose dosage having the greatest effect on the colour changes (ΔE). Fructose addition notably reduced free amino acids (FAAs) and cystine contents. Furthermore, phenylalanine decreased with increasing dosages of arabinose, xylose, and fructose. Glutamic acid content decreased significantly with fructose addition but showed insignificant changes with xylose. At the same dosage, the addition of pentoses resulted in the production of more sulphur-containing volatile compounds like methional, 2-[(methylthio) methyl] furan, and dimethyl disulphide than hexoses. Methional and furfural, which provide a roasted, savoury flavour, were produced by adding more xylose. Heat treatment with xylose also removed hexanal, the main off-odourant.

5.
Int J Biol Macromol ; 262(Pt 2): 130167, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38360226

RESUMO

This study investigated the characteristics of polysaccharides from date pomace using microwave-assisted deep eutectic solvents. The impact on the gut microbiota and probiotics growth was examined in vitro. The study also examined its antioxidant properties, ability to inhibit enzymes linked to diabetes and high blood pressure, impact on cell growth, and physical properties. The isolated MPS had an average molecular weight of 8073.38 kDa and contained mannose, galacturonic acid, galactose, glucose, and fructose in specific proportions. At a concentration of 1000 mg/L, MPS showed strong antioxidant activity, with significant scavenging rates in various tests such as DPPH (57.0 ± 1.05 %) and ABTS (66.4 ± 2.48 %). MPS displayed 77 %, 80 %, and 43 % inhibition for α-amylase, α-glucosidase, and ACE-inhibition, respectively. MPS displayed significant antiproliferative effects, achieving 100 % and 99 % inhibition against Caco-2 and MCF-7 cells at 2500 mg/L, respectively. MPS showed broad-spectrum antibacterial properties against both Gram-positive and Gram-negative foodborne bacteria. Gemmiger formicilis, Blautia species, Collinsella aerofaciens, and Bifidobacterium longum showed strong positive correlations, suggesting increased SCFA production. Network analysis indicated species correlations, with 86 % showing negative correlations with Escherichia and Enterococcus saccharolyticus. MPS was abundant in Firmicutes, Actinobacteria, and Proteobacteria phyla. Date pomace could serve as a dietary fiber source, promoting better health.


Assuntos
Microbioma Gastrointestinal , Prebióticos , Humanos , Solventes Eutéticos Profundos , Células CACO-2 , Micro-Ondas , Polissacarídeos/farmacologia , Bactérias Gram-Negativas
6.
Heliyon ; 10(2): e25007, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38312583

RESUMO

Fermented soybean products have played a significant role in Asian diets for a long time. Due to their diverse flavours, nutritional benefits, and potential health-promoting properties, they have gained a huge popularity globally in recent years. Traditionally, soybean fermentation is conducted spontaneously, using microorganisms naturally present in the environment, or inoculating with traditional starter cultures. However, many potential health risks are associated with consumption of these traditionally fermented soybean products due to the presence of food pathogens, high levels of biogenic amines and mycotoxins. The use of starter culture technology in fermentation has been well-studied in recent years and confers significant advantages over traditional fermentation methods due to strict control of the microorganisms inoculated. This review provides a comprehensive review of microbial safety and health risks associated with consumption of traditional fermented soybean products, and how adopting starter culture technology can help mitigate these risks to ensure the safety of these products.

7.
Food Chem X ; 21: 101178, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38357377

RESUMO

In this study, okara was fermented with probiotic strains Lactobacillus gasseri LAC 343 and Limosilactobacillus fermentum PCC, respectively. Significant increases in cell count (by 2.22 log CFU/mL for LAC and 0.82 log CFU/mL for PCC) and significant decreases in pH (by 1.31 for LAC and 1.03 for PCC) were found in fermented okara slurry. In addition, strain LAC tended to produce amino acids, while strain PCC depleted most amino acids. An untargeted metabolomic-based approach using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to further understand the compositional changes and potential health benefits by identifying bioactive metabolites in fermented okara slurry. We successfully identified various beneficial bioactive compounds including γ-aminobutyric acid, indolelactic acid, d-phenyllactic acid, and p-hydroxyphenyllactic acid which had differences in fold-changes in okara slurry fermented with different strains. Our study indicated the feasibility of using probiotics to ferment okara for novel functional food development.

8.
Food Chem ; 442: 138483, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38241989

RESUMO

Valorization of fruit by-products is a crucial area of research for the development of innovative bio-based products. This study investigated the physicochemical properties and health-promoting benefits of date syrup waste, both fermented by Pichia cecembensis or Pichia kudriavzevii (FDSW), and unfermented (CDSW). Metabolomics profiles of these samples were identified post in vitro digestion. FDSW exhibited 42 volatile compounds, including 9 new ones, and contained (-)-epicatechin, tyrosol, and gallic acid. Bioaccessible fractions of FDSW demonstrated substantial α-amylase inhibition, with percentages of 40.7 % and 53.9 %, respectively. FDSW displayed superior cytotoxicity against Caco2 and MCF-7 cancer cell lines, with an average of âˆ¼75 % and 56 %, respectively. Untargeted metabolomics analysis revealed an increase in secondary metabolites, totaling 27 metabolites. LC-QTOF analysis of bioaccessible carbohydrate metabolites in FDSW identified two phytochemical groups, alkaloids, and terpenoids. This study underscores the potential of FDSW for producing value-added bio-based products with desirable characteristics and health benefits.


Assuntos
Frutas , Ácido Gálico , Humanos , Células CACO-2 , Frutas/química , Ácido Gálico/análise , Antioxidantes/análise , Metabolômica
9.
Food Chem X ; 21: 101073, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38235344

RESUMO

Exopolysaccharides (EPSs) are carbohydrate polymers that can be produced from probiotic bacteria. This study characterized the EPSs from Enterococcus faecium (EPS-LB13) and Streptococcus thermophilus (EPS-MLB10) and evaluated their biological and technological potential. The EPSs had high molecular weight and different monosaccharide compositions. The EPSs exhibited various biological activities at 250 mg/L, such as scavenging free radicals (10 % to 88.8 %), enhancing antioxidant capacity (714 to 2848 µg/mL), inhibiting pathogens (53 % to 74 %), and suppressing enzymes and cancer cells (2 % to 83 %), etc. The EPSs supported the growth of beneficial gut bacteria from Proteobacteria, Bacteroidetes, Firmicutes, and Acinetobacter in fecal fermentation with total Short-chain fatty acids production from 5548 to 6023 PPM. Moreover, the EPSs reduced the gelation time of fermented skimmed bovine milk by more than half. These results suggest that the EPSs from LB13 and MLB10 have promising applications in the dairy and pharmaceutical industries.

10.
J Dairy Sci ; 107(5): 2573-2585, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37977446

RESUMO

Camel milk (CM), known for its immune-regulatory, anti-inflammatory, antiapoptotic, and antidiabetic properties, is a natural healthy food. It is easily digestible due to the high levels of ß-casein and diverse secreted antibodies, exhibiting superior antibacterial and antiviral activities compared with bovine milk. ß-casein is less allergic and more digestible because it is more susceptible to digestive hydrolysis in the gut; therefore, higher levels of ß-casein make CM advantageous for human health. Furthermore, antibodies help the digestive system by destroying the antigens, which are then overwhelmed and digested by macrophages. The connection between the gut microbiota and human health has gained substantial research attention, as it offers potential benefits and supports disease treatment. The gut microbiota has a vital role in regulating the host's health because it helps in several biological functions, such as protection against pathogens, immune function regulation, energy harvesting from digested foods, and reinforcement of digestive tract biochemical barriers. These functions could be affected by the changes in the gut microbiota profile, and gut microbiota differences are associated with several diseases, such as inflammatory bowel disease, colon cancer, irritable bowel disorder, mental illness, allergy, and obesity. This review focuses on the digestibility of CM components, particularly protein and fat, and their influence on gut microbiota modulation. Notably, the hypoallergenic properties and small fat globules of CM contribute to its enhanced digestibility. Considering the rapid digestion of its proteins under conditions simulating infant gastrointestinal digestion, CM exhibits promise as a potential alternative for infant formula preparation due to the high ß-/αs-casein ratio and protective proteins, in addition to the absence of ß-lactoglobulin.

11.
J Food Sci ; 89(1): 540-551, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38051025

RESUMO

Soy whey, a by-product from the tofu and soy protein isolate industry was evaluated as a substrate for a biofortified beverage using several propionic acid bacteria (PAB). PAB growth and changes in sugars, organic acids, amino acids and isoflavones were investigated. Vitamin B12 and short-chain fatty acid (SCFA) production were measured over time. Acidipropionibacterium acidipropionici (DSM 20272) showed the highest growth, compared to the other three PABs (Propionibacterium freudenreichii [DSM 20271 and DSM 4902], A. jensenii [DSM 20535]). Acidipropionibacterium (DSM 20272 and DSM 20535) showed the best propionic acid and acetic acid production, while P. freudenreichii produced the most succinic acid. Propionibacterium freudenreichii exhibited significant vitamin B12 production at 4.06 ± 0.28 µg/L for DSM 20271, followed by 2.58 ± 0.22 µg/L for DSM 4902. Notably, all PAB displayed strong ß-glycosidase activities evidenced by the conversion of isoflavone glycosides to isoflavone aglycones. The stark differences between Acidipropionibacterium spp. and Propionibacterium spp. indicate that the former PAB is specialized in SCFA production, while the latter PAB is better at vitamin B12 bioenrichment. This study demonstrated the possibility of employing PAB fermentation to improve SCFA and vitamin B12 content. This can open avenues for a beverage or functional ingredient development.


Assuntos
Isoflavonas , Alimentos de Soja , Propionatos/metabolismo , Soro do Leite/metabolismo , Propionibacterium/metabolismo , Proteínas do Soro do Leite/metabolismo , Fermentação , Bactérias/metabolismo , Biotransformação , Isoflavonas/metabolismo , Vitaminas/metabolismo
12.
J Dairy Sci ; 107(5): 2706-2720, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38056563

RESUMO

Making cheese from camel milk (CM) presents various challenges due to its different physicochemical properties compared with bovine milk (BM). In this study, we investigated the chemical composition, proteolysis, meltability, oiling off, texture profile, color, microstructure, and rheological properties of low-fat Cheddar cheese (LFCC) prepared from BM-CM blends. LFCC was produced from BM or BM supplemented with 15% CM (CM15) and 30% CM (CM30), and analyzed after 14, 60, 120, and 180 d of ripening at 8°C. Except for salt content, no significant differences were observed among LFCC from BM, CM15, and CM30. The addition of CM increased the meltability and oiling off in the resulting cheese throughout storage. With respect to color properties, after melting, LFCC CM30 showed lower L* values than LFCC made from BM and CM15, and a* and b* values were higher than those of BM and CM15 samples. LFCC from CM30 also exhibited lower hardness compared with the other cheeses. Moreover, LFCC made from BM showed a rough granular surface, but cheese samples made from BM-CM blends exhibited a smooth surface. The rheological parameters, including storage modulus, loss modulus, and loss tangent, varied among cheese treatments. The determined acetoin and short-chain volatile acids (C2-C6) in LFCC were affected by the use of CM, because CM15 showed significantly higher amounts than BM and CM30, respectively. The detailed interactions between BM and CM in the cheese matrix should be further investigated.

13.
Sci Rep ; 13(1): 17888, 2023 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-37857676

RESUMO

Exopolysaccharides (EPSs) possess distinctive rheological and physicochemical properties and innovative functionality. This study aimed to investigate the physicochemical, bioactive, and rheological properties of an EPS secreted by Lactococcus lactis subsp. lactis C15. EPS-C15 was found to have an average molecular weight of 8.8 × 105 Da and was identified as a hetero-EPS composed of arabinose, xylose, mannose, and glucose with a molar ratio of 2.0:2.7:1.0:21.3, respectively. The particle size and zeta potential represented 311.2 nm and - 12.44 mV, respectively. FITR exhibited that EPS-C15 possessed a typical polysaccharide structure. NMR displayed that EPS-C15 structure is → 3)α-d-Glcvi (1 → 3)α-d-Xylv (1 → 6)α-d-Glciv(1 → 4)α-d-Glc(1 → 3)ß-d-Man(1 → 2)α-d-Glci(1 → . EPS-C15 scavenged DPPH and ABTS free radicals with 50.3% and 46.4% capacities, respectively. Results show that the antiproliferative activities of EPS-C15 revealed inhibitions of 49.7% and 88.1% against MCF-7 and Caco-2 cells, respectively. EPS-C15 has antibacterial properties that inhibited Staphylococcus aureus (29.45%), Salmonella typhimurium (29.83%), Listeria monocytogenes (30.33%), and E. coli O157:H7 (33.57%). The viscosity of EPS-C15 decreased as the shear rate increased. The rheological properties of the EPS-C15 were affected by changes in pH levels and the addition of salts. EPS-C15 is a promising biomaterial that has potential applications in various industries, such as food, pharmaceuticals, and healthcare.


Assuntos
Escherichia coli O157 , Lactococcus lactis , Probióticos , Humanos , Células CACO-2 , Polissacarídeos/química , Probióticos/química , Polissacarídeos Bacterianos/química
14.
Crit Rev Food Sci Nutr ; : 1-31, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37667831

RESUMO

Metabolic by-products are part of the so-called postbiotics of probiotics and other beneficial microorganisms, particularly lactic acid bacteria, which have gained popularity as a feasible alternative to improving food quality and safety. Postbiotics in dry and liquid forms can be easily integrated into food formulations and packaging materials, exhibiting antimicrobial and antioxidant effects owing to the presence of multiple antimicrobials, such as organic acids, bacteriocins, exopolysaccharides and bioactive peptides. Postbiotics can thus control the growth of pathogens and spoilage microorganisms, thereby extending the shelf life of food products. Because of their ability to be easily manufactured without requiring extensive processing, postbiotics are regarded as a safer and more sustainable alternative to synthetic preservatives, which can have negative environmental consequences. Additionally, food manufacturers can readily adopt postbiotics in food formulations without significant modifications. This systematic review provides an in-depth analysis of studies on the use of postbiotics in the biopreservation and packaging of a wide range of food products. The review evaluates and discusses the types of microorganisms, postbiotics preparation and modification techniques, methods of usage in dairy products, meat, poultry, seafood, fruits, vegetables, bread, and egg, and their effects on food quality and safety.

15.
J Dairy Sci ; 106(10): 6671-6687, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37562642

RESUMO

During fermentation, camel milk forms a fragile, acid-induced gel, which is less stable compared with the gel formed by bovine milk. In this study, camel milk was supplemented with different levels of soy extract, and the obtained blends were fermented with 2 different starter culture strains (a high acidic culture and a low acidic culture). The camel milk-soy extract yogurt treatments were evaluated for pH value, acidity, total phenolic compounds, antioxidant capacities, degree of hydrolysis, α-amylase and α-glucosidase inhibition, angiotensin-converting enzyme inhibition, antiproliferative activities, and rheological properties after 1 and 21 d of storage at 4°C. The results revealed that some of the investigated parameters were significantly affected by the starter culture strain and storage period. For instance, the effect of starter cultures was evident for the degree of hydrolysis, antioxidant capacities, proliferation inhibition, and rheological properties because these treatments led to different responses. Furthermore, the characteristics of camel milk-soy extract yogurt were also influenced by the supplementation level of soy extract, particularly after 21 d of storage. This study could provide valuable knowledge to the dairy industry because it highlighted the characteristics of camel milk-soy yogurt prepared with 2 different starter culture strains.


Assuntos
Camelus , Leite , Animais , Leite/química , Camelus/metabolismo , Viscosidade , Antioxidantes/metabolismo , Iogurte , Fermentação
16.
Microorganisms ; 11(5)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37317192

RESUMO

Probiotics, prebiotics, and functional foods are buzzwords in the food industry for good reasons [...].

17.
Poult Sci ; 102(8): 102791, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37307633

RESUMO

Animal and poultry processing generates significant volumes of by-products that can be further processed for other uses. In this study, we treated minced chicken carcasses with proteases to produce protein hydrolysates that can be used as nutritional and/or flavor-enhancing ingredients. Five different microbial proteases were investigated for their abilities to hydrolyse the minced chicken carcass: Flavourzyme, Protamex, PB01, PB02, and PB03, with PB02 demonstrating the highest degree of hydrolysis (DH) of the minced chicken carcass (43.95%) after 4 h of hydrolysis. The essential hydrolytic parameters were optimized using response surface methodology in conjunction with Box-Behnken design. The optimal conditions were found to be: enzyme/substrate ratio of 3:100 (w/w), temperature of 51.20°C, pH of 6.62 ± 0.05, and substrate/water ratio of 1:1 (w/v) for 4-h hydrolysis, which resulted in a maximum DH of 45.44%. The protein recovery was 50.45 ± 2.05%, and the protein hydrolysate was high in free amino acids (7,757.31 mg/100 mL), of which essential and taste-active amino acids accounted for 41.74% and 92.64%, respectively. The hydrolysate was comprised mainly of low molecular weight peptides (1-5 kDa, 0.5-1 kDa, and <0.5 kDa), which were potential taste substances and flavor precursors. The resulting hydrolysate might be employed as a nutritive product, an ingredient for flavoring generation or a component of fermentation media.


Assuntos
Galinhas , Hidrolisados de Proteína , Animais , Hidrólise , Hidrolisados de Proteína/química , Galinhas/metabolismo , Peptídeo Hidrolases/metabolismo , Aminoácidos
18.
Foodborne Pathog Dis ; 20(5): 177-185, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37097316

RESUMO

The demand for rapid and accurate detection methods for Salmonella Enteritidis necessitates the development of highly sensitive and specific biosensors to ensure proper monitoring of food safety and quality requirements in the food sector and to secure human health. This study focused on development of a polyaniline/zinc oxide (PANI/ZnO) nanocomposite film on a gold electrode conductometric immunosensor for detection of Salmonella Enteritidis. The sensor was modified with monoclonal anti-Salmonella Enteritidis antibodies as biorecognition elements. The fabricated sensor was able to detect and quantify the target pathogen within 30 min and showed a good detection range from 101 to 105 colony-forming units (CFU)/mL for Salmonella Enteritidis and a minimum detection limit of 6.44 CFU/mL in 0.1% peptone water. Additionally, the fabricated sensor showed good selectivity and detection limit toward the target bacterium and successfully determined Salmonella Enteritidis content in ultrahigh heat-treated skim milk samples without pretreatment of the food sample.


Assuntos
Técnicas Biossensoriais , Nanocompostos , Óxido de Zinco , Humanos , Animais , Salmonella enteritidis , Limite de Detecção , Leite/microbiologia , Imunoensaio
19.
J Agric Food Chem ; 71(10): 4337-4345, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36861492

RESUMO

Organosulfur compounds (OSCs) in coffee remain challenging to analyze by conventional gas chromatography (GC) due to their low concentrations amid coffee's complex matrix and susceptibility to chiral-odor influences. In this study, multidimensional GC (MDGC) methods were developed to profile OSCs in coffee. Conventional GC was compared to comprehensive GC (GC×GC) for untargeted OSC analysis in eight specialty coffees, and GC×GC was found to improve the fingerprinting of OSCs in coffee (50 vs 16 OSCs identified). Of the 50 OSCs, 2-methyltetrahydrothiophen-3-one (2-MTHT) was of high interest due to its chirality and known aroma contribution. Following that, a heart-cutting method for chiral GC (GC-GC) was developed, validated, and applied to the coffees. The mean enantiomer ratio of 2-MTHT was observed to be 1.56 (R/S) in brewed coffees. Overall, MDGC techniques allowed for more comprehensive analyses of coffee OSCs, from which (R)-2-MTHT was found to be the predominant enantiomer with the lower odor threshold.


Assuntos
Café , Odorantes , Café/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Odorantes/análise , Cromatografia Gasosa/métodos
20.
Foods ; 12(6)2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36981088

RESUMO

In the present work, the modification of spent coffee grounds (SCG) hydrolysate composition by mixed cultures of a non-Saccharomyces yeast, Lachancea thermotolerans, and a lactic acid bacterium, Lactiplantibacillus plantarum, as well as their interactions, were evaluated. It was found that L. plantarum inhibited the growth and survival of L. thermotolerans as compared with that in the yeast alone. On the other hand, the growth and survival of L. plantarum was slowed in sequential fermentation, but not in co-culture. Compared with co-culture, higher ethanol content, less residual sugars, and less acetic and succinic acids were found in sequential fermentation. In addition, lower amounts of caffeine and phenolic acids (e.g., ferulic, caffeic, and p-coumaric acids) were obtained in mixed (co- and sequential) cultures with corresponding levels of volatile phenols relative to the yeast monoculture. Moreover, co-culturing resulted in the highest contents of total alcohols (ethanol excluded) and total esters. Therefore, mixed culturing of L. plantarum and L. thermotolerans presented positive effects on the chemical constituents of fermented SCG hydrolysates, which might be a new alternative approach to valorizing the SCG into novel alcoholic drinks with different ethanol and flavor constituents.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...