Inhibitory effect of polysaccharides on acrylamide formation in chemical and food model systems

Melastoma candidum D. Don, a Taiwanese folk medicinal plant, has high levels of antibacterial and bactericidal activity. Our aim was to determine whether and to what extent an acetone extract of this plant inhibits the growth of foodborne pathogenic bacteria. M. candidum acetone extract had marked inhibitory effect on test bacteria introduced into sliced pork, which was then stored at 4°C. At the end of storage (day 12), the bacterial concentrations dropped by 1.59 to 2.91 log CFU/g compared with the control. In steamed rice stored at 30°C, a 0.2% extract decreased initial (before storage) concentrations of Bacillus cereus from 2.01 log CFU/g to an undetectable level, which remained for at least 24 h. After 72 to 168 h of storage, test bacterial concentrations were reduced by 2.59 to 5.66 log CFU/g. In fresh noodles stored at 30°C, both initial and final bacterial concentrations were decreased. At the end of storage (72 to 168 h), test bacteria concentrations were reduced by 1.85 to 2.88 log CFU/g. Overall, M. candidum acetone extract had an inhibitory effect on foodborne pathogenic bacteria in different food model systems.

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Yeasts as Complementary Model Systems for the Study of the Pathological Repercussions of Enhanced Synphilin-1 Glycation and Oxidation

International Journal of Molecular Sciences ◽

10.3390/ijms22041677 ◽

2021 ◽

Vol 22 (4) ◽

pp. 1677

Author(s):

David Seynnaeve ◽

Daniel P. Mulvihill ◽

Joris Winderickx ◽

Vanessa Franssens

Keyword(s):

Lewy Bodies ◽

Inhibitory Effect ◽

Model Systems ◽

Wild Type ◽

Glyoxalase System ◽

Inclusion Formation ◽

Growth Defects ◽

Yeast Strains ◽

Autophagic Degradation ◽

Detrimental Impact

Synphilin-1 has previously been identified as an interaction partner of α-Synuclein (αSyn), a primary constituent of neurodegenerative disease-linked Lewy bodies. In this study, the repercussions of a disrupted glyoxalase system and aldose reductase function on Synphilin-1 inclusion formation characteristics and cell growth were investigated. To this end, either fluorescent dsRed-tagged or non-tagged human SNCAIP, which encodes the Synphilin-1 protein, was expressed in Saccharomyces cerevisiae and Schizosaccharomyces pombe yeast strains devoid of enzymes Glo1, Glo2, and Gre3. Presented data shows that lack of Glo2 and Gre3 activity in S. cerevisiae increases the formation of large Synphilin-1 inclusions. This correlates with enhanced oxidative stress levels and an inhibitory effect on exponential growth, which is most likely caused by deregulation of autophagic degradation capacity, due to excessive Synphilin-1 aggresome build-up. These findings illustrate the detrimental impact of increased oxidation and glycation on Synphilin-1 inclusion formation. Similarly, polar-localised inclusions were observed in wild-type S. pombe cells and strains deleted for either glo1+ or glo2+. Contrary to S. cerevisiae, however, no growth defects were observed upon expression of SNCAIP. Altogether, our findings show the relevance of yeasts, especially S. cerevisiae, as complementary models to unravel mechanisms contributing to Synphilin-1 pathology in the context of neurodegenerative diseases.

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Enhancing the enzymatic browning inhibition capacity of Moringa oleifera seed extract via the Maillard reaction

African Journal of Food, Agriculture, Nutrition and Development ◽

10.18697/ajfand.103.20065 ◽

2021 ◽

Vol 21 (103) ◽

pp. 18518-18532

Author(s):

Norah Vhangani Lusani ◽

◽

L Mogashoa ◽

J Van Wyk

Keyword(s):

Maillard Reaction ◽

Inhibitory Effect ◽

Model Systems ◽

Enzymatic Browning ◽

Brown Pigment ◽

Pigment Formation ◽

Browning Inhibition ◽

Seed Extracts

The antioxidant and anti-browning activity of heated plant extracts have been attributed to the formation of Maillard reaction products (MRPs) via the Maillard reaction (MR). The inhibitory effect of heated Moringa oleifera (MO) seed extract on banana polyphenol oxidase (PPO) was investigated. The Plain MO seed extracts and those with added glucose and glycine (1.5 mM each) were heated at 100°C for 15, 30, 60 and 120 min. The pH and brown colour development decreased and increased significantly (P <0.05) with increased reaction time, respectively, with heated moringa glucose-glycine HMGGL for 120 min exhibiting the highest pH reduction (2.58) and darkest extracts at an L* value of 8.11. This phenomenon is associated with progression of the MR. With reference to enzymatic browning, heated MO seed extracts exhibited stronger inhibitory effect against banana PPO activity in vivo and in vitro than the unheated counterpart. Evident to this are the higher inhibition percentages and lower ΔE values. Among model systems, the highest in vitro browning inhibition was exhibited mostly by longer heating times of 60 and 120 min. Model system HMGGL 120 min proved to be superior at 96% inhibition, which was comparable to known synthetic commercial antioxidants such as ascorbic acid (AA) at 99%, as well as ethylenediaminetetraacetic acid (EDTA) and citric acid (CA), both at 100% inhibition. In vivo enzymatic browning inhibition followed a similar trend, where the brown pigment (melanin) intensified as shown by an increase in ΔE as the storage time increased from 0.5 to 24 h. The model system UMGGL exhibited highest inhibition of brown melanin (p <0.05). Although it was the best amongst other model systems, it was surpassed by synthetic antioxidants AA, EDTA and CA, which were ranked amongst the top three in inhibiting brown pigment formation in vivo. To further illustrate the effect of MR augmented MO seed extracts on enzyme activity inhibition, UMGGL 60 and 120 at 5 and 24 h storage surpassed the inhibitory effect of AA. At the said storage times, AA lost its inhibitory potential against pigment formation. This was due to oxidation of AA to form dehydroascorbic acid, which lacks inhibitory potential. This study proved that heating MO plant extracts increases their enzymatic browning inhibition potential, furthermore, the inhibitory capacity was heightened when reacted via the MR.

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Influence of citral on acrylamide formation in model systems

Food Chemistry ◽

10.1016/j.foodchem.2022.132097 ◽

2022 ◽

pp. 132097

Author(s):

Yuchen Zhu ◽

Ruimin Xu ◽

Yinghua Luo ◽

Guoyu Sun ◽

Mengyi Lin ◽

...

Keyword(s):

Model Systems ◽

Acrylamide Formation

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Impact of pH on the Kinetics of Acrylamide Formation/Elimination Reactions in Model Systems

Journal of Agricultural and Food Chemistry ◽

10.1021/jf0611264 ◽

2006 ◽

Vol 54 (20) ◽

pp. 7847-7855 ◽

Cited By ~ 32

Author(s):

Kristel De Vleeschouwer ◽

Iesel Van der Plancken ◽

Ann Van Loey ◽

Marc E. Hendrickx

Keyword(s):

Model Systems ◽

Acrylamide Formation ◽

Elimination Reactions ◽

Kinetics Of

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Effect of microstructure and initial cell conditions on thermal inactivation kinetics and sublethal injury of Listeria monocytogenes in fish-based food model systems

Food Microbiology ◽

10.1016/j.fm.2019.103267 ◽

2019 ◽

Vol 84 ◽

pp. 103267 ◽

Cited By ~ 5

Author(s):

Davy Verheyen ◽

Maria Baka ◽

Simen Akkermans ◽

Torstein Skåra ◽

Jan F. Van Impe

Keyword(s):

Listeria Monocytogenes ◽

Thermal Inactivation ◽

Model Systems ◽

Inactivation Kinetics ◽

Initial Cell ◽

Sublethal Injury ◽

Food Model ◽

Effect Of Microstructure

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A Comparative Study of Two Food Model Systems To Test the Survival of Campylobacter jejuni at −18°C

Journal of Food Protection ◽

10.4315/0362-028x-69.11.2635 ◽

2006 ◽

Vol 69 (11) ◽

pp. 2635-2639 ◽

Cited By ~ 18

Author(s):

TINA BIRK ◽

HANNE ROSENQUIST ◽

LONE BRØNDSTED ◽

HANNE INGMER ◽

ANETTE BYSTED ◽

...

Keyword(s):

Campylobacter Jejuni ◽

Brain Heart Infusion ◽

Skin Surface ◽

Model Systems ◽

Skin Model ◽

Cell Counts ◽

Chicken Skin ◽

Liquid Model ◽

Determining Factor ◽

Food Model

The survival of Campylobacter jejuni NCTC 11168 was tested at freezing conditions (−18°C) over a period of 32 days in two food models that simulated either (i) the chicken skin surface (skin model) or (ii) the chicken juice in and around a broiler carcass (liquid model). In the skin model, cells were suspended in chicken juice or brain heart infusion broth (BHIB) and added to 4-cm2 skin pieces, which were subsequently stored at −18°C. In the liquid model, cells were suspended in chicken juice or BHIB and stored at −18°C. The decrease in the number of viable C. jejuni NCTC 11168 cells was slower when suspended in chicken juice than in BHIB. After freezing for 32 days, the reductions in the cell counts were 1.5 log CFU/ml in chicken juice and 3.5 log CFU/ml in BHIB. After the same time of freezing but when inoculated onto chicken skin, C. jejuni NCTC 11168 was reduced by 2.2 log units when inoculated in chicken juice and 3.2 log units when inoculated into BHIB. For both models, the major decrease occurred within the first 24 h of freezing. The results obtained in the liquid model with chicken juice were comparable to the reductions of Campylobacter observed for commercially processed chickens. The survival at −18°C in the liquid model was also tested for three poultry isolates and three human clinical isolates of the serotypes 1.44, 2, and 4 complex. As observed for C. jejuni NCTC 11168, all the strains survived significantly better in chicken juice than in BHIB and were not notably influenced by serotype or origin. The findings indicate that the composition of the medium around the bacteria, rather than the chicken skin surface, is the major determining factor for the survival of C. jejuni at freezing conditions. The liquid model with chicken juice was therefore the best model system to study the freezing tolerance in Campylobacter strains.

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