scholarly journals Effects of Frozen Storage on Viability of Probiotics and Antioxidant Capacities of Synbiotic Riceberry and Sesame-Riceberry Milk Ice Creams

2020 ◽  
Vol 8 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Varongsiri Kemsawasd ◽  
Pittaya Chaikham

According to many recent studies, ice cream was found to be an effective carrier of probiotics along the human gastrointestinal tract. While probiotics have long been known to improve gut health, prebiotic-supplemented ice creams have demonstrated properties that could be linked to various health benefits and improvement of the gut microbiota. In this study, riceberry and sesame-riceberry milk ice creams were supplemented with inulin, Lactobacillus casei 01 and Lactobacillus acidophilus LA5 to examine the changes of probiotic populations in different formulations of ice cream. The survivability of probiotics after 60 days of frozen storage and the level of viable cell tolerance towards the simulated gastrointestinal environment were also assessed, followed by sensory evaluation with 100 untrained panelists and determination of chemical qualities of ice cream samples. Findings revealed L. casei 01 to be more resistant to frozen storage compared to L acidophilus LA5, whereas addition of sesame milk and inulin were shown to minimize levels of viable cell loss following environmental and mechanical stress, suggesting enhanced probiotic activity. Significant reductions in probiotic viability were observed for all ice cream samples, however higher survival rates were observed in prebiotic-supplemented samples prior to and after 60 days of frozen storage. Probiotic cell counts in all samples exceeded the minimum recommended value (6 log CFU/g). In simulated gastric and bile fluid, all samples illustrated a significant change in probiotic levels, which significantly decreased with increase time of exposure to acidic and basic conditions. Probiotic strains in samples containing riceberry, sesame and inulin demonstrated greatest survivability as observed by reduction in pH and increased total acidity, with increased antioxidant and phenolic contents. On the other hand, changes in physicochemical properties of ice cream lowered overall sensory scores in terms of color and flavor. This study contributes to future development and applications of riceberry and sesame for inducement of synbiotic effects in novel probiotic products.

1996 ◽  
Vol 59 (5) ◽  
pp. 476-480 ◽  
Author(s):  
J. P. DEAN ◽  
E. A. ZOTTOLA

The survival characteristics of Listeria monocytogenes V7 were investigated in a full fat (10% fat) and reduced fat (3%) ice cream. The effect of nisin on the survival of Listeria monocytogenes in the ice creams was also evaluated. Ice cream mixes varying in composition were manufactured and inoculated with L. monocytogenes, passed through a “soft serve” freezer and then frozen at −18°C for up to 3 months. Samples were removed from storage throughout the three months, thawed, and then plated on Listeria-selective agar. In the samples that did not contain nisin, no reduction in the cell population was observed throughout manufacture and frozen storage. When nisin was present in the ice cream, a significant reduction in the cell population (P < .05) was observed. At the end of 3 months of frozen storage, no Listeria cells were detected in the 3% fat ice cream containing nisin. The effect of nisin on Listeria cells was decreased somewhat in the higher fat ice cream but this decrease was not significant over the 3 month storage. The stability of nisin in the ice cream remained constant throughout storage at −18°C.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S643-S643
Author(s):  
Maria F Mojica ◽  
Christopher Bethel ◽  
Emilia Caselli ◽  
Magdalena A Taracila ◽  
Fabio Prati ◽  
...  

Abstract Background Catalytic mechanisms of serine β-lactamases (SBL; classes A, C and D) and metallo-β-lactamases (MBLs) have directed divergent strategies towards inhibitor design. SBL inhibitors act as high affinity substrates that -as in BATSIs- form a reversible, dative covalent bond with the conserved active site Ser. MBL inhibitors bind the active-site Zn2+ ions and displace the nucleophilic OH-. Herein, we explore the efficacy of a series of BATSI compounds with a free-thiol group at inhibiting both SBL and MBL. Methods Exploratory compounds were synthesized using stereoselective homologation of (+) pinandiol boronates to introduce the amino group on the boron-bearing carbon atom, which was subsequently acylated with mercaptopropanoic acid. Representative SBL (KPC-2, ADC-7, PDC-3 and OXA-23) and MBL (IMP-1, NDM-1 and VIM-2) were purified and used for the kinetic characterization of the BATSIs. In vitro activity was evaluated by a modified time-kill curve assay, using SBL and MBL-producing strains. Results Kinetic assays revealed that IC50 values ranged from 1.3 µM to >100 µM for this series. The best compound, s08033, demonstrated inhibitory activity against KPC-2, VIM-2, ADC-7 and PDC-3, with IC50 in the low μM range. Reduction of at least 1.5 log10-fold of viable cell counts upon exposure to sub-lethal concentrations of antibiotics (AB) + s08033, compared to the cells exposed to AB alone, demonstrated the microbiological activity of this novel compound against SBL- and MBL-producing E. coli (Table 1). Table 1 Conclusion Addition of a free-thiol group to the BATSI scaffold increases the range of these compounds resulting in a broad-spectrum inhibitor toward clinically important carbapenemases and cephalosporinases. Disclosures Robert A. Bonomo, MD, Entasis, Merck, Venatorx (Research Grant or Support)


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
E. Silva-Avellaneda ◽  
K. Bauer-Estrada ◽  
R. E. Prieto-Correa ◽  
M. X. Quintanilla-Carvajal

AbstractThe use of oleogels is an innovative and economical option for the technological development of some food products, among them ice creams. The aim of this study was to establish the best processing conditions to obtain an emulsion which form oleogels with the lowest ζ-potential and average droplet size (ADS) for use as ice cream base. Using surface response methodology (SRM), the effects of three numerical factors (microfluidization pressure, oil and whey protein concentration, WP) and four categorical factors (oil type, temperature, surfactant, and type of WP) on formation of emulsions were assessed. The response variables were ζ, ADS, polydispersity index (PDI), viscosity (η), hardness, cohesiveness and springiness. Additionally, a numerical optimization was performed. Two ice creams containing milk cream and oleogel, respectively were compared under the optimization conditions. Results suggest oleogels obtained from the microfluidization of whey and high oleic palm oil are viable for the replacement of cream in the production of ice cream.


2006 ◽  
Vol 72 (5) ◽  
pp. 3482-3488 ◽  
Author(s):  
M�nica Ordax ◽  
Ester Marco-Noales ◽  
Mar�a M. L�pez ◽  
Elena G. Biosca

ABSTRACT Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper.


2015 ◽  
Vol 12 (106) ◽  
pp. 20150069 ◽  
Author(s):  
Hiroki Takahashi ◽  
Taku Oshima ◽  
Jon L. Hobman ◽  
Neil Doherty ◽  
Selina R. Clayton ◽  
...  

Zinc is essential for life, but toxic in excess. Thus all cells must control their internal zinc concentration. We used a systems approach, alternating rounds of experiments and models, to further elucidate the zinc control systems in Escherichia coli . We measured the response to zinc of the main specific zinc import and export systems in the wild-type, and a series of deletion mutant strains. We interpreted these data with a detailed mathematical model and Bayesian model fitting routines. There are three key findings: first, that alternate, non-inducible importers and exporters are important. Second, that an internal zinc reservoir is essential for maintaining the internal zinc concentration. Third, our data fitting led us to propose that the cells mount a heterogeneous response to zinc: some respond effectively, while others die or stop growing. In a further round of experiments, we demonstrated lower viable cell counts in the mutant strain tested exposed to excess zinc, consistent with this hypothesis. A stochastic model simulation demonstrated considerable fluctuations in the cellular levels of the ZntA exporter protein, reinforcing this proposal. We hypothesize that maintaining population heterogeneity could be a bet-hedging response allowing a population of cells to survive in varied and fluctuating environments.


Author(s):  
Yash S. Raval ◽  
Abdelrhman Mohamed ◽  
Jayawant N. Mandrekar ◽  
Cody Fisher ◽  
Kerryl E. Greenwood-Quaintance ◽  
...  

Wound infections are caused by bacteria and/or fungi. The presence of fungal biofilms in wound beds presents a unique challenge, as fungal biofilms may be difficult to eradicate. The goal of this work was to assess the in vitro anti-biofilm activity of a H 2 O 2 -producing electrochemical bandage (e-bandage) against 15 yeast isolates representing commonly-encountered species. Time-dependent decreases in viable biofilm CFU counts of all isolates tested were observed, resulting in no visible colonies with 48 hours of exposure by plate culture. Fluorescence microscopic analysis showed extensive cell membrane damage of biofilm cells after e-bandage treatment. Reductions in intracellular ATP levels of yeast biofilm cells were recorded post e-bandage treatment. Our results suggest that exposure to H 2 O 2 -producing e-bandages reduce in vitro viable cell counts of yeast biofilms, making this a potential new topical treatment approach for fungal wound infections.


Author(s):  
R. Doucette ◽  
M. Fisman ◽  
V.C. Hachinski ◽  
H. Mersky

Abstract:We examined the degree of neuronal loss from the nucleus basalis of Meynert (nbM) in two groups of Alzheimer patients differing in the degree of intellectual impairment. Significant cell loss from the nbM was found only in the more severely demented group of patients. Mean cell counts (per lOu, paraffin section) were compiled separately for the anterior, intermediate and posterior subdivisions of the human nbM in three groups of subjects: Group 1 (N = 4) was severely demented and was untestable on the Extended Scale for Dementia (ESD) for at least the last two years of life; Group 2 (N = 4) was less demented and had completed at least one ESD test within 12 months of death; Group 3 (five controls) had died of non-neurological causes. In Group 2 there was a small (but insignificant) trend toward cell loss in the anterior subdivision, and a normal complement of neurons in both the intermediate and posterior subdivisions. There was, however, significant cell loss from all subdivisions of Group 1. How these cell counts may relate to the severity of the dementia is discussed.


Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1777
Author(s):  
Shaghayegh Haghani ◽  
Milad Hadidi ◽  
Shiva Pouramin ◽  
Fateme Adinepour ◽  
Zahra Hasiri ◽  
...  

In this study, cornelian cherry (Cornus mas L.) peel (CCP) was incorporated into a probiotic ice cream formulation containing Bifidobacterium lactis to investigate the potential effect of CCP on the viability of B. lactis in the ice cream after simulated gastrointestinal stress and during 120 days of storage. Furthermore, the effect of the addition of CCP (3, 6, and 9%) on bioactive compounds, antioxidant activity, and physicochemical and sensory attributes of the ice cream was evaluated. The results showed that the addition of CCP significantly enhanced vitamin C, total polyphenols, total anthocyanin content, and antioxidant activity of the ice cream. During frozen storage of the ice cream, phenolic compounds and anthocyanins were quite stable, but vitamin C significantly decreased. The addition of CCP had no significant effect on the viability of B. lactis throughout the freezing process, but increments of 6% and 9% CCP increased the viability of B. lactis in the ice cream and after simulated gastrointestinal processes in all storage periods. These findings imply that CCP is a promising candidate to be used for producing functional ice cream.


2020 ◽  
Author(s):  
Iris Martínez-Rodero ◽  
Tania García-Martínez ◽  
Erika Alina Ordóñez-León ◽  
Meritxell Vendrell-Flotats ◽  
Carlos Olegario-Hidalgo ◽  
...  

Abstract Background VitTrans is a device that enables the vitrification and warming/dilution of in vitro produced bovine embryos followed by their direct transfer to recipient females in field conditions. This study sought to improve the VitTrans method by comparing two equilibration times: short (SE: 3 min) and long (LE: 12 min). Outcome measures recorded in vitrified D7 and D8 expanded blastocysts were survival and hatching rates, differential cell counts, apoptosis rate and gene expression. Results While survival rates at 3 h and 24 h post-warming were reduced (P < 0.05) after vitrification, hatching rates of D7 embryos vitrified after SE were similar to those obtained in fresh non-vitrified blastocysts. Hatching rates of vitrified D8 blastocysts were lower (P < 0.05) than of fresh controls, regardless of treatment. Total cell counts, and inner cell mass and trophectoderm cell numbers were similar in hatched blastocysts derived from D7 blastocysts vitrified after SE and fresh blastocysts, while vitrified D8 blastocysts yielded lower values, regardless of treatment. The rate of apoptotic cells was significantly higher in both treatment groups when compared to fresh controls, although apoptosis rates were lower using the SE than LE protocol. No differences emerged in expression of the genes BAX, AQP3, CX43 and IFNτ between blastocysts vitrified after SE or LE, whereas a significantly higher abundance of BCL2L1 and SOD1 transcripts was observed in blastocysts vitrified after SE compared to LE. Conclusions The VitTrans device combined with a shorter exposure to the equilibration medium improves vitrification/warming outcomes facilitating the direct transfer of vitrified embryos under field conditions.


1963 ◽  
Vol 11 (4) ◽  
pp. 305-309
Author(s):  
A. F. Gaudy ◽  
F. Abu-Niaaj ◽  
E. T. Gaudy

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