Isolation of quinic acid from dropped Citrus reticulata Blanco fruits: its derivatization, antibacterial potential, docking studies, and ADMET profiling.

Citrus reticulata dropped fruits are generally discarded as waste, causing environmental pollution and losses to farmers. In the present study, column chromatography has been used to isolate quinic acid (1,3,4,5-tetrahydroxycyclohexane-1-carboxylic acid) from the ethyl acetate fraction of a methanol extract of citrus fruits dropped in April. Quinic acid is a ubiquitous plant metabolite found in various plants and microorganisms. It is an important precursor in the biosynthesis of aromatic natural compounds. It was further derivatized into 3,4-o-isopropylidenequinic acid 1,5-lactone (QA1), 1,3,4,5-tetraacetoxycyclohexylaceticanhydride (QA2), and cyclohexane-1,2,3,5-tetraone (QA3). These compounds were further tested for their antibacterial potential against the foodborne pathogens Staphylococcus aureus, Bacillus spp., Yersinia enterocolitica, and Escherichia coli. QA1 exhibited maximum antibacterial potential (minimum inhibitory concentration; 80-120 µg/mL). QA1 revealed synergistic behavior with streptomycin against all the tested bacterial strains having a fractional inhibitory concentration index ranging from 0.29 to 0.37. It also caused a significant increase in cell constituent release in all the tested bacteria compared to the control, along with prominent biofilm reduction. The results obtained were further checked with computational studies that revealed the best docking score of QA1 (-6.30 kcal/mol, -5.8 kcal/mol, and -4.70 kcal/mol) against ß-lactamase, DNA gyrase, and transpeptidase, respectively. The absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis revealed that the drug-like properties of QA1 had an ideal toxicity profile, making it a suitable candidate for the development of antimicrobial drugs.

Integrating Association Mapping, Linkage Mapping, Fine Mapping with RNA Seq Conferring Seedling Vigor Improvement for Successful Crop Establishment in Deep Sown Direct-Seeded Rice.

BACKGROUND: Ongoing large-scale shift towards direct seeded rice (DSR) necessitates a convergence of breeding and genetic approaches for its sustenance and harnessing natural resources and environmental benefits. Improving seedling vigour remains key objective for breeders working with DSR. The present study aims to understand the genetic control of seedling vigour in deep sown DSR. Combined genome-wide association mapping, linkage mapping, fine mapping, RNA-sequencing to identify candidate genes and validation of putative candidate genes were performed in the present study. RESULTS: Significant phenotypic variations were observed among genotypes in both F3:4:5 and BC2F2:3 populations. The mesocotyl length showed significant positive correlation with %germination, root and shoot length. The 881 kb region on chromosome 7 reported to be associated with mesocotyl elongation. RNA-seq data and RT-PCR results identified and validated seven potential candidate genes. The four promising introgression lines free from linkage drag and with longer mesocotyl length, longer root length, semi-dwarf plant height have been identified. CONCLUSION: The study will provide rice breeders (1) the pre breeding material in the form of anticipated DSR adapted introgression lines possessing useful traits and alleles improving germination under deep sown DSR field conditions (2) the base for the studies involving functional characterization of candidate genes. The development and utilization of improved introgression lines and molecular markers may play an important role in genomics-assisted breeding (GAB) during the pyramiding of valuable genes providing adaptation to rice under DSR. Our results offer a robust and reliable package that can contribute towards enhancing genetic gains in direct seeded rice breeding programs.

Antibiotic resistance in potential probiotic lactic acid bacteria of fermented foods and human origin from Nigeria.

INTRODUCTION: Probiotic lactobacilli are generally recognized as safe (GRAS) and are being used in several food and pharma formulations. However, growing concern of antibiotic resistance in bacterial strains of food origin and its possible transmission via functional foods is increasingly being emphasized. OBJECTIVES: This study screened potential probiotic lactic acid bacteria (LAB) strains for their phenotypic and genotypic antibiotic resistance profiles. METHODS: Susceptibility to different antibiotics was assayed by the Kirby Bauer standard disc diffusion protocol. Both conventional and SYBR-RTq-PCR were used for detection of resistance coding genes. RESULTS: A variable susceptibility pattern was documented against different antibiotic classes. LAB strains irrespective of origin displayed marked phenotypic resistance against cephalosporins, aminoglycosides, quinolones, glycopeptides; and methicillin among beta-lactams with few exceptions. In contrast, high sensitivity was recorded against macrolides, sulphonamides and carbapenems sub-group of beta-lactams with some variations. parC, associated with ciprofloxacin resistance was detected in 76.5% of the strains. Other prevalent resistant determinants observed were aac(6?)Ii (42.1%), ermB, ermC (29.4%), and tetM (20.5%). Six (?17.6%) of the isolates were free from genetic resistance determinants screened in this study. CONCLUSION: Study revealed presence of antibiotic resistance determinants among lactobacilli from both fermented foods and human sources.

Milk-Derived Antimicrobial Peptides: Overview, Applications, and Future Perspectives.

The growing consumer awareness towards healthy and safe food has reformed food processing strategies. Nowadays, food processors are aiming at natural, effective, safe, and low-cost substitutes for enhancing the shelf life of food products. Milk, besides being a rich source of nutrition for infants and adults, serves as a readily available source of precious functional peptides. Due to the existence of high genetic variability in milk proteins, there is a great possibility to get bioactive peptides with varied properties. Among other bioactive agents, milk-originated antimicrobial peptides (AMPs) are gaining interest as attractive and safe additive conferring extended shelf life to minimally processed foods. These peptides display broad-spectrum antagonistic activity against bacteria, fungi, viruses, and protozoans. Microbial proteolytic activity, extracellular peptidases, food-grade enzymes, and recombinant DNA technology application are among few strategies to tailor specific peptides from milk and enhance their production. These bioprotective agents have a promising future in addressing the global concern of food safety along with the possibility to be incorporated into the food matrix without compromising overall consumer acceptance. Additionally, in conformity to the current consumer demands, these AMPs also possess functional properties needed for value addition. This review attempts to present the basic properties, synthesis approaches, action mechanism, current status, and prospects of antimicrobial peptide application in food, dairy, and pharma industry along with their role in ensuring the safety and health of consumers.

Antioxidative, anti-inflammatory, and anticancer properties of the red biopigment extract from Monascus purpureus (MTCC 369).

In this study, the Monascus purpureus (MTCC 369) extracted biopigment produced by solid-state fermentation was evaluated for its therapeutic potential using human prostate LNCaP cells. Antioxidant efficacy of the red biopigment determined using 2,2 diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, and ferric reducing antioxidant power assays was found to be 53.16%, 86.27%, and 13.83%, respectively. In addition, expression studies of target gene superoxide dismutase 2 (SOD-2) showed that increasing concentrations (10-50 µg/ml) of the biopigment enhanced its expression from 0.91- to 1.905-fold. An inhibitory effect of 0.424-0.627-fold was observed in the expression of glutathione peroxidase (GPX) with a similar increase in biopigment concentration. Addition of quercetin (positive control) at 50 µg/ml led to 0.295-fold decrease in GPX expression. In contrast, the expression of SOD-2 increased by 1.026-fold in the presence of quercetin. The biopigment also showed an increased serological IL-10 expression (an anti-inflammatory agent) ranging from 1034.58 to 4657.89 pg/ml. Treatment of LNCaP cells with the red biopigment (10-100 µg/ml) resulted in significant (p < .05) reduction (upto 79.86%) in viability and 51.79%-89.86% reduction in cell metabolic activity. Fluorescent microscopy examination of red biopigment-treated cells showed significant inhibition of normal cellular morphology including condensed nuclei, membrane blebbing, and apoptotic bodies, thus confirming its cytotoxic potential. Results of this study revealed that the red biopigment has the potential to modulate the expression of antioxidative and anti-inflammatory markers in addition to being cytotoxic to the LNCaP cancer cells. PRACTICAL APPLICATIONS: These findings indicate that cell treatment with red biopigment has the potential to modulate anti-oxidative, pro-inflammatory and anti-inflammatory genes for therapeutic effects, which is further enhanced by its cytotoxic activity against cancer cells. Considering these cell-based observations, Monascus red biopigment has ample potential as a useful supplement to formulate therapeutic products that delay the development of inflammatory-related diseases and associated complications.

Development and validation of multiplex SYBR Green real-time PCR assays for detection and molecular surveillance of four tick-borne canine haemoparasites.

Two multiplex SYBR Green based real-time PCR assays were standardized and evaluated to detect DNA from four canine haemoparasites (Babesia gibsoni, Babesia vogeli, Ehrlichia canis and Hepatozoon canis), along with internal controls from dogs from selected districts of Punjab state, India. Amplicons of 126 bp, 337 bp, 234 bp and 106 bp corresponding to B. gibsoni (18S rRNA gene), B. vogeli (18S rRNA gene), E. canis (virB9 gene), and H. canis (18S rRNA gene) were obtained, without any non-specific amplification. Microscopic evaluation of 200 blood samples from dogs revealed the prevalence of B. gibsoni, E. canis and H. canis as 1.5%, 1.5% and 1.0%, respectively, while with the multiplex real-time PCR assays the values for B. gibsoni, B. vogeli, E. canis, and H. canis were 8.0%, 1.5%, 3.5% and 23.5%, respectively, with concurrent infections of B. gibsoni and H. canis (3.5%); E. canis and H. canis (2.0%) and B. gibsoni, B. vogeli, E. canis, and H. canis (0.5%). The diagnostic sensitivity of the multiplex real-time PCR assays with respect to microscopy in the detection of B. gibsoni, E. canis and H. canis was 100% while the specificity for B. gibsoni, B. vogeli, E. canis, and H. canis was 93%, 100%, 98% and 77%, respectively, revealing the respective strength of agreement as ″fair″, ″slight″, ″moderate″ and ″slight″ by kappa value statistics, and the data were statistically significant, for detection of B. gibsoni and E. canis infections, by Fisher's exact test. The analytical sensitivity of the multiplex PCR assays in detection of DNAs was 8.59 × 105 and 9.9 × 106 copies for B. vogeli and E. canis, respectively, and 1.15 × 106 and 3.41 × 105 copies for B. gibsoni and H. canis, respectively. Assessment of risk factors viz. age, sex, breed, season and locations showed no significant association with the prevalence of these haemoparasites except for B. vogeli, E. canis and H. canis where significant associations were found for location, age and breed, respectively by multiplex real-time PCR assays.

Duplex real-time PCR methods for molecular detection and characterization of canine tick-borne haemoparasites from Punjab state, India.

BACKGROUND: Microscopy is a routinely used technique for the diagnosis of canine tick-borne haemoparasitic diseases in various clinical laboratories worldwide. In an attempt to provide better diagnostic assay to the clients for effective management of these diseases duplex real-time PCR assays were applied. METHODS AND RESULTS: Blood samples (n = 338) aseptically collected from suspected dogs of Central Plain Zone of Punjab state, India were subjected to SYBR Green based real-time duplex PCR assays for simultaneous detection of B. vogeli & E. canis and B. gibsoni & H. canis. Results revealed an overall prevalence rate of canine tick-borne haemoparasites as 54.1%, amongst which H. canis was the predominant (25.4%), followed by B. gibsoni (16.3%), E. canis (10.7%) and B. vogeli (1.8%). Sensitivity and specificity of the duplex assays ranged from 59.04 to 100.0% and 58.12 to 92.52%, respectively and their strength of agreement was ″fair″ with kappa value statistics. A significant (p < 0.05) association between prevalence of B. gibsoni, H. canis and E. canis infection with risk factors like sex, breed, season and location was recorded. The ancestral background of the field isolates of haemoparasites was also studied by phylogenetic analysis of their nucleotide sequences. CONCLUSIONS: SYBR Green dye based duplex real-time PCR assays proved to be highly sensitive, specific, rapid and affordable diagnostic tests for use by clinicians to save the life of pets.

Natural pigment from Monascus: The production and therapeutic significance.

OBJECTIVE: The present review highlights the advantages of using natural colorant over the synthetic one. We have discussed the fermentation parameters that can enhance the productivity of Monascus pigment on agricultural wastes. BACKGROUND: Food industry is looking for natural colours because these can enhance the esthetic value, attractiveness, and acceptability of food while remaining nontoxic. Many synthetic food colours (Azorubine Carmoisine, quinoline) have been prohibited due to their toxicity and carcinogenicity. Increasing consumer awareness towards the food safety has forced the manufacturing industries to look for suitable alternatives. In addition to safety, natural colorants have been found to have nutritional and therapeutic significance. Among the natural colorants, microbial pigments can be considered as a viable option because of scalability, easier production, no seasonal dependence, cheaper raw materials and easier extraction. Fungi such as Monascus have a long history of safety and therefore can be used for production of biopigments. METHOD: The present review summarizes the predicted biosynthetic pathways and pigment gene clusters in Monascus purpureus. RESULTS: The challenges faced during the pilot-scale production of Monascus biopigment and taming it by us of low-cost agro-industrial substrates for solid state fermentation has been suggested. CONCLUSION: Keeping in mind, therapeutic properties of Monascus pigments and their derivatives, they have huge potential for industrial and pharmaceutical application. APPLICATION: Though the natural pigments have wide scope in the food industry. However, stabilization of pigment is the greatest challenge and attempts are being made to overcome this by complexion with hydrocolloids or metals and by microencapsulation.

Application of Deep Learning on Student Engagement in e-learning environments.

The drastic impact of COVID-19 pandemic is visible in all aspects of our lives including education. With a distinctive rise in e-learning, teaching methods are being undertaken remotely on digital platforms due to COVID-19. To reduce the effect of this pandemic on the education sector, most of the educational institutions are already conducting online classes. However, to make these digital learning sessions interactive and comparable to the traditional offline classrooms, it is essential to ensure that students are properly engaged during online classes. In this paper, we have presented novel deep learning based algorithms that monitor the student's emotions in real-time such as anger, disgust, fear, happiness, sadness, and surprise. This is done by the proposed novel state-of-the-art algorithms which compute the Mean Engagement Score (MES) by analyzing the obtained results from facial landmark detection, emotional recognition and the weights from a survey conducted on students over an hour-long class. The proposed automated approach will certainly help educational institutions in achieving an improved and innovative digital learning method.

A deep learning and grad-CAM based color visualization approach for fast detection of COVID-19 cases using chest X-ray and CT-Scan images.

The world is suffering from an existential global health crisis known as the COVID-19 pandemic. Countries like India, Bangladesh, and other developing countries are still having a slow pace in the detection of COVID-19 cases. Therefore, there is an urgent need for fast detection with clear visualization of infection is required using which a suspected patient of COVID-19 could be saved. In the recent technological advancements, the fusion of deep learning classifiers and medical images provides more promising results corresponding to traditional RT-PCR testing while making detection and predictions about COVID-19 cases with increased accuracy. In this paper, we have proposed a deep transfer learning algorithm that accelerates the detection of COVID-19 cases by using X-ray and CT-Scan images of the chest. It is because, in COVID-19, initial screening of chest X-ray (CXR) may provide significant information in the detection of suspected COVID-19 cases. We have considered three datasets known as 1) COVID-chest X-ray, 2) SARS-COV-2 CT-scan, and 3) Chest X-Ray Images (Pneumonia). In the obtained results, the proposed deep learning model can detect the COVID-19 positive cases in  ≤  2 seconds which is faster than RT-PCR tests currently being used for detection of COVID-19 cases. We have also established a relationship between COVID-19 patients along with the Pneumonia patients which explores the pattern between Pneumonia and COVID-19 radiology images. In all the experiments, we have used the Grad-CAM based color visualization approach in order to clearly interpretate the detection of radiology images and taking further course of action.

Application of deep learning for fast detection of COVID-19 in X-Rays using nCOVnet.

Presently, COVID-19 has posed a serious threat to researchers, scientists, health professionals, and administrations around the globe from its detection to its treatment. The whole world is witnessing a lockdown like situation because of COVID-19 pandemic. Persistent efforts are being made by the researchers to obtain the possible solutions to control this pandemic in their respective areas. One of the most common and effective methods applied by the researchers is the use of CT-Scans and X-rays to analyze the images of lungs for COVID-19. However, it requires several radiology specialists and time to manually inspect each report which is one of the challenging tasks in a pandemic. In this paper, we have proposed a deep learning neural network-based method nCOVnet, an alternative fast screening method that can be used for detecting the COVID-19 by analyzing the X-rays of patients which will look for visual indicators found in the chest radiography imaging of COVID-19 patients.

Probiotic mediated NF-κB regulation for prospective management of type 2 diabetes.

Diabetes and other lifestyle disorders have been recognized as the leading cause of morbidity and mortality globally. Nuclear factor kappa B (NF-κB) is a major factor involved in the early pathobiology of diabetes and studies reveal that hyperglycemic conditions in body leads to NF-κB mediated activation of several cytokines, chemokines and inflammatory molecules. NF-κB family comprises of certain DNA-binding protein factors that elicit the transcription of pro-inflammatory molecules. Various studies have identified NF-κB as a promising target for diabetic management. Probiotics have been proposed as bio-therapeutic agents for treatment of inflammatory disorders and many other chronic clinical stages. The precise mechanisms by which probiotics acts is yet to be fully understood, however research findings have indicated their role in NF-κB modulation. The current review highlights NF-κB as a bio-therapeutic target for probable management of type 2 diabetes through probiotic intervention.

Impairment of Cronobacter sakazakii and Listeria monocytogenes biofilms by cell-free preparations of lactobacilli of goat milk origin.

Biofilm-associated bacterial infections represent one of the major threats to modern medical treatments. Bacteria encased in biofilm matrix are more resistant towards antimicrobials and thus the capability of microbes to persist and nurture in a biofilm seems to be the foremost aspect of pathogenesis and therapeutic failure. Therefore, there is a pressing demand for new drugs active against microbial biofilms. In the current study, anti-biofilm potential of Lactobacillus spp. cell-free supernatants (CFSs) against Cronobacter sakazakii and Listeria monocytogenes was characterized using crystal violet staining and MTT assay. CFSs of goat milk origin lactobacilli not only prevented biofilm formation but also disrupted preformed biofilms. Neutralized and heat-treated preparations of Lactobacillus CFSs also inhibited biofilm formation by test pathogens. The results were quantitatively confirmed by light and fluorescent microscopy observations. Biofilms developed under static conditions displayed typical compact microcolonies with uniform distribution over the surface, while upon CFS challenge, biofilms were disrupted with presence of dead cells. These findings highlight the anti-biofilm potency of Lactobacillus spp. strains of goat milk origin and their potential application in food industries.

Screening of cell surface properties of potential probiotic lactobacilli isolated from human milk.

Evaluation of eleven candidate probiotic Lactobacillus strains isolated from human milk showed that some of the strains were well endowed with desirable cell surface and attachment attributes. The cell surface properties (hydrophobicity, auto-aggregation, attachment to collagen and HT-29 monolayer) of probiotic Lactobacillus species of human milk origin were compared with reference probiotic/ non-probiotic species and pathogenic strains. The bacterial adhesion to hydrocarbons (BATH) was determined using three aliphatic (Chloroform, n-Hexane and n-Octane) and two aromatic (Toluene and Xylene) solvents. Maximum affinity of Lactobacillus strains towards chloroform and toluene indicated the presence of low electron acceptor/ acidic surface components on cell surface of most of the strains. The highest value of per cent hydrophobicity was recorded with chloroform in HM1 (L. casei) (97·10 ± 3·35%) and LGG (98·92 ± 1·24%). A moderate auto-aggregation attribute was observed in all of our Lactobacillus isolates. Only HM10, HM12 and HM13 exhibited comparatively enhanced precipitation rate after 7 h of incubation period. The adhesion potential to collagen matrix was highest in LGG (26·94 ± 5·83%), followed by HM1 (11·07 ± 3·54%) and HM9 (10·85 ± 1·74%) whereas, on HT-29 cells, HM8 (14·99 ± 3·61%), HM3 (13·73 ± 1·14%) and HM1 (11·21 ± 3·18%) could adhere effectively. In this manner, we noticed that although the cell surface properties and adhesion prospective of probiotic bacteria were strain dependent, five of our isolates viz. HM1, HM3, HM8, HM9 and HM10 exhibited promising cell surface properties, which could be further targeted as indigenous probiotic.

Assessment of the antibiofilm and antiquorum sensing activities of Eucalyptus globulus essential oil and its main component 1,8-cineole against methicillin-resistant Staphylococcus aureus strains.

Antibacterial resistance is an increasingly serious threat to global public health. The search for new anti-infection agents from natural resources, with different mode of actions and competitive effects became a necessity. In this study, twenty height methicillin-resistant Staphylococcus aureus (MRSA) strains were investigated for their biofilm formation ability. Subsequently, the antibiofilm effects of Eucalyptus globulus essential oil and its main component 1,8-cineole, against MRSA, as well as their antiquorum sensing potential, were evaluated. Our results displayed the potent efficacy of both E. globulus essential oil and 1,8-cineole against the development of biofilms formed by the methicillin-resistant strains. Additionally, E. globulus essential oil showed more potent of anti-QS activity, even at a low concentration, when compared to 1,8-cineole. All these property of tested agents may pave the way to prevent the development of biofilm formation by MRSA and subsequently the spreading of nosocomial infection.

Microencapsulation of reuterin to enhance long-term efficacy against food-borne pathogen Listeria monocytogenes.

The aim of this study was to microencapsulate the reuterin produced by Lactobacillus reuteri BPL-36 strain for its long-term efficacy against food-borne pathogen Listeria monocytogenes. Lactobacillus reuteri BPL-36 strain previously isolated from a human infant fecal sample in lab was selected for the present study based on its ability to produce reuterin. The organism displayed a broad-spectrum antimicrobial activity. Reuterin concentration of 89.63 mM was obtained in the MRS-glycerol medium after 16 h incubation at 37 °C. The reuterin concentration required to inhibit the growth of Pseudomonas aeruginosa, Escherichia coli O157: H7, Salmonella typhi, Staphylococcus aureus, and Listeria monocytogenes was found to be 1.0, 2.0, 2.0, 4.0, and 10.0 AU/mL, respectively. Microencapsulation of reuterin to enhance long-term efficacy against food-borne pathogens was done. Results in this study indicated that the release characteristics of reuterin from the encapsulated particles were pH dependent. The release characteristics were unaffected by the storage of encapsulated reuterin at 4 °C for 2 weeks. The anti-listerial efficacy of the encapsulated reuterin was tested against L. monocytogenes in the BHI medium adjusted to pH 5.0 with a reuterin content equivalent to 16 mM, similar to un-encapsulated (free) reuterin. Encapsulated reuterin demonstrated enhanced efficacy against L. monocytogenes for longer duration of time when compared with un-encapsulated (free) reuterin. The present work demonstrated a novel antimicrobial delivery system that ensured much better capability of inhibiting the growth of L. monocytogenes throughout 24 h incubation at 37 °C.

Nanotechnology: An Untapped Resource for Food Packaging.

Food commodities are packaged and hygienically transported to protect and preserve them from any un-acceptable alteration in quality, before reaching the end-consumer. Food packaging continues to evolve along-with the innovations in material science and technology, as well as in light of consumer's demand. Presently, the modern consumers of competitive economies demands for food with natural quality, assured safety, minimal processing, extended shelf-life and ready-to-eat concept. Innovative packaging systems, not only ascertains transit preservation and effective distribution, but also facilitates communication at the consumer levels. The technological advances in the domain of food packaging in twenty-first century are mainly chaired by nanotechnology, the science of nano-materials. Nanotechnology manipulates and creates nanometer scale materials, of commercial and scientific relevance. Introduction of nanotechnology in food packaging sector has significantly addressed the food quality, safety and stability concerns. Besides, nanotechnology based packaging intimate's consumers about the real time quality of food product. Additionally, nanotechnology has been explored for controlled release of preservatives/antimicrobials, extending the product shelf life within the package. The promising reports for nanotechnology interventions in food packaging have established this as an independent priority research area. Nanoparticles based food packages offer improved barrier and mechanical properties, along with food preservation and have gained welcoming response from market and end users. In contrary, recent advances and up-liftment in this area have raised various ethical, environmental and safety concerns. Policies and regulation regarding nanoparticles incorporation in food packaging are being reviewed. This review presents the existing knowledge, recent advances, concerns and future applications of nanotechnology in food packaging sector.

Effect of ß-glucan fortification on physico-chemical, rheological, textural, colour and organoleptic characteristics of low fat dahi.

Fortified low fat functional dahi prepared by supplementing skimmed buffalo milk with ß-glucan (0.25, 0.50, 0.75 and 1.0%) was assessed for physico-chemical, rheological, textural, colour and sensorial characteristics. Total solids in dahi increased significantly with the increase in ß-glucan concentration, however, values of fat, protein and ash varied non-significantly upon ß-glucan addition in dahi. ß-glucan at 0.5% solids levels, produced low fat dahi with superior quality, less whey separation and good textural properties than the samples containing other levels. Syneresis and viscosity was positively affected with the addition of ß-glucan till 0.5% level and higher concentration caused destabilization of the product. Fortified dahi showed greater firmness and consistent than control dahi sample. The addition of 0.5% level of ß-glucan also imparted significantly better instrumental color values and sensory scores with attractive or natural dahi color when compared to control dahi samples and other dahi samples prepared with different levels of ß-glucan.

Bacillus As Potential Probiotics: Status, Concerns, and Future Perspectives.

Spore-forming bacilli are being explored for the production and preservation of food for many centuries. The inherent ability of production of large number of secretory proteins, enzymes, antimicrobial compounds, vitamins, and carotenoids specifies the importance of bacilli in food chain. Additionally, Bacillus spp. are gaining interest in human health related functional food research coupled with their enhanced tolerance and survivability under hostile environment of gastrointestinal tract. Besides, bacilli are more stable during processing and storage of food and pharmaceutical preparations, making them more suitable candidate for health promoting formulations. Further, Bacillus strains also possess biotherapeutic potential which is connected with their ability to interact with the internal milieu of the host by producing variety of antimicrobial peptides and small extracellular effector molecules. Nonetheless, with proposed scientific evidences, commercial probiotic supplements, and functional foods comprising of Bacillus spp. had not gained much credential in general population, since the debate over probiotic vs pathogen tag of Bacillus in the research and production terrains is confusing consumers. Hence, it's important to clearly understand the phenotypic and genotypic characteristics of selective beneficial Bacillus spp. and their substantiation with those having GRAS status, to reach a consensus over the same. This review highlights the probiotic candidature of spore forming Bacillus spp. and presents an overview of the proposed health benefits, including application in food and pharmaceutical industry. Moreover, the growing need to evaluate the safety of individual Bacillus strains as well as species on a case by case basis and necessity of more profound analysis for the selection and identification of Bacillus probiotic candidates are also taken into consideration.

Antibacterial effects of Lactobacillus isolates of curd and human milk origin against food-borne and human pathogens.

This study was undertaken to assess the antibacterial efficacy of lactobacilli isolated from curd and human milk samples. Identities of thirty-one different lactobacilli (20 from curd and 11 from human milk) were confirmed by genus-specific PCR and 16S rRNA-based sequencing. These strains belonged to five species, Lactobacillus casei, L. delbrueckii, L. fermentum, L. plantarum, and L. pentosus. Antibacterial activities of cell-free supernatants (CFSs) of all the Lactobacillus isolates were estimated through standard agar-well diffusion assay, against commonly occurring food-borne and clinically important human pathogens. None of the lactobacilli cell-free supernatant (CFS) exhibited inhibitory activity against four pathogens, namely Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Klebsiella pneumoniae. Bacillus cereus, Salmonella enterica serovar Typhi, and Shigella flexneri were moderately inhibited by majority of CFSs, whereas, weak activity was observed against Pseudomonas aeruginosa and Proteus mirabilis. CFS of some of the curd isolates displayed antagonistic activity against Streptococcus mutans; however, human milk lactobacilli did not displayed any inhibitory activity against them. As expected, Nisin (Nisaplin®) showed inhibitory activity against Gram-positive, S. aureus, B. cereus, and L. monocytogenes. Interestingly, few of the examined CFSs exhibited inhibitory activities against both Gram-positive and Gram-negative pathogens. Findings from this study support the possibility to explore the tested lactobacilli and their CFSs as natural bio-preservatives, alone or in combination with approved bacteriocins in food and pharma formulations after validating their safety.