食品与工业微生物学杂志

Objective: Purification and characterization of β-galactosidase from Lactobacillus brevis PLA28 were carried out and transgalactosylation activity was also studied for the synthesis of galacto-oligosaccharides (GOS). Methods: β-Galactosidase was purified by using ammonium sulphate precipitation method and hydrophobic interaction chromatography. Reaction conditions were optimized for the assay of this β-galactosidase. GOS synthesis was carried out under the optimized reaction conditions in batch mode and the product formed was detected by thin layered chromatography (TLC). Results: β-Galactosidase was purified to 6.6 fold with a yield of 6% and specific activity of 4 U/mg protein. Molecular weight of the purified β-galactosidase was found to be 45 and 60 kDa on SDS PAGE and 105 kDa on native PAGE. The temperature and pH optima of purified enzyme were 30°C and pH 6.5 respectively. The enzyme was found to be stable at 30°C for 6 h. Vmax and KM of the purified β-galactosidase were calculated to be 6.6 U/mg protein and 8.33 mM respectively. GOS synthesis was observed at pH 6.5, 30°C in 6-8 h of incubation by purified enzyme. Conclusion: Lactobacillus brevis PLA28 β-galactosidase has exhibited capability for transgalactosylation reaction with lactose conversion to synthesize GOS.

The purpose of this investigation was to examine the bactericidal activity of long lifetime ozone water (LLO water) against pathogenic bacteria of medical, veterinary, and public health interest. An electrolytic system using Pt mesh electrodes combined with a conventional polymer electrolyte, the Nafion 117 membrane, produced LLO water from tap water with high efficiency. LLO water killed 7.144 ± 0.0507 log10 CFU of Escherichia coli O157:H7, 6.979 ± 0.045 log10 CFU of methicillin-resistant Staphylococcus aureus, 6.503 ± 0.3681 log10 CFU of Pseudomonas aeruginosa and 6.579 ± 0.123 log10 CFU of Legionella pneumophila within one minute. In contrast, endospores of Bacillus anthracis were killed within 20 min. Results of observation of the bactericidal activity of LLO by using an electron microscope, it was revealed that LLO water was shown the bactericidal action by swelling and destroying on the cell wall of the bacterial cells. Our studies demonstrated that LLO water has the potential to be widely applicable in food hygiene, medicine and veterinary medicine as a sterilizing agent. This is the first study to demonstrate the bactericidal activity and characteristics of LLO water.

Despite of old methods, an emerging technology of Fourier Transform Infrared (FTIR) spectroscopy has been appeared to use as a promising application for the detection of adulteration in food. FTIR method works on the principal of interaction of electromagnetic radiations with the molecules of specific food with defined energy. In this review, the three regions of electromagnetic spectra including near infrared, mid infrared and far infrared are the points of spotlight. For food industry, FTIR method is expedient, automatic, time saving and most importantly, it shows non-destructive analysis of food physically as well as chemically. Moreover, FTIR in collaboration with the authentic commendable data analytical system appeared as a tremendous appeal for descriptive test of food from extremely large quantity to its trivial component level, showing dramatically potential for adulteration analysis with the substantial contrivance for the quality control progressions. A systematic review of literaturehas been performed to amass the information of FTIR technique as non destructive method for analysis of intentionally added harmful chemicals from existing research publications.

A central composite experimental design was used to evaluate optimal conditions of the medium component, pH and temperature for cyclodextrin glycosyltransferase production from sorghum by Bacillus circulans (American Type Culture Collection). Sorghum concentration, initial pH and temperature were optimized using the response surface method. Maximal CGTase production of 216.94 U.mL-1 was obtained after 48 hours of fermentation when the concentrations of the medium were 0.16% sifted sorghum, 0.5% triptone, 0.5% yeast extract, 1% sodium carbonate, 0.1% K2HPO4, 0.02% MgSO4•7 H2O, initial pH of 8.0 and temperature of 35°C under rotational shaking. Further studies aimed at increasing the fermentation scale using optimal conditions for the high enzymatic production and high volumetric productivity are needed to improve the fermentation process described in the present study.

The antioxidants play an important role in the preservation of foods and the management of oxidative stress related diseases by acting on reactive oxygen species and free radicals. However, their use in high temperature processed food and pharmaceuticals are limited due to its low thermal stability. The objective of the study was to use the biofield energy treatment on butylated hydroxytoluene (BHT) i.e. antioxidant and analyse its impact on the physical, thermal, and spectral properties of BHT. For the study, the sample was divided into two groups and termed as control and treated. The treated group was subjected to biofield energy treatment. The characterization of treated sample was done using X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and UV-visible (UV-Vis) spectroscopy. The XRD results showed the alteration in lattice parameters, unit cell volume, and molecular weight along with 14.8% reduction in the crystallite size of treated sample as compared to the control. The DSC analysis showed an increase in the latent heat of fusion from 75.94 J/g (control) to 96.23 J/g in the treated BHT sample. The TGA analysis showed an increase in onset temperature of decomposition (130°C→136°C) and maximum thermal decomposition temperature (152.39°C→158.42°C) in the treated sample as compared to the control. Besides, the FT-IR analysis reported the shifting of aromatic C-H stretching peak towards higher frequency (3068→3150 cm-1) and C=C stretching towards lower frequency (1603→1575 cm-1) as compared to the control sample. Moreover, the UV spectrum also revealed the shifting of the peak at λmax 247 nm (control) to 223 nm in the treated sample. The overall results showed the impact of biofield energy treatment on physical, thermal and spectral properties of BHT sample.