Evaluation of long- and short-term storage conditions and efficiency of a novel microencapsulated Salmonella phage cocktail for controlling Salmonella in chicken meat

This study aims to assess the stability and activity of using a lyophilization, formulation design and to evaluate their efficiency for controlling Salmonella in chicken meat. The phage-loaded 0.3 M sucrose gelatin mixture at 4 and 25 °C displayed significantly less phage titer loss (p < 0.05) than the other excipients and liquid phage cocktail in 12 months. The results showed that there were significant reductions of Salmonella at the end of the storage in chicken meat for newly prepared phage powder (1.86 log CFU/cm2 and 2.18 log CFU/cm2), lyophilized phage powders stored at 4 °C (1.08 log CFU/cm2 and 1.26 log CFU/cm2) and stored at 25 °C (0.66 log CFU/cm2 and 1.00 log CFU/cm2) for 10 months at MOI 100 and 1000, respectively. The results demonstrated that lyophilized phages in a simple food grade formulation can be successfully stored and might be used in biocontrol of Salmonella in meat.

Analysis of corn and sorghum flour mixtures using laser-induced breakdown spectroscopy

BACKGROUND

In a world constantly challenged by climate change, corn and sorghum are two important grains because of their high productivity and adaptability, and their multifunctional use for different purposes such as human food, animal feed, and feedstock for many industrial products and biofuels. Corn and sorghum can be utilized interchangeably in certain applications; one grain may be preferred over the other for several reasons. The determination of the composition corn and sorghum flour mixtures may be necessary for economic, regulatory, environmental, functional, or nutritional reasons.

RESULTS

Laser-induced breakdown spectroscopy (LIBS) in combination with chemometrics, was used for the classification of flour samples based on the LIBS spectra of flour types and mixtures using partial least squares discriminant analysis (PLS-DA) and the determination of the sorghum ratio in sorghum / corn flour mixture based on their elemental composition using partial least squares (PLS) regression. Laser-induced breakdown spectroscopy with PLS-DA successfully identified the samples as either pure corn, pure sorghum, or corn-sorghum mixtures. Moreover, the addition of various levels of sorghum flour to mixtures of corn-sorghum flour were used for PLS analysis. The coefficient of determination values of calibration and validation PLS models are 0.979 and 0.965, respectively. The limit of detection of the PLS models is 4.36%.

CONCLUSION

This study offers a rapid method for the determination of the sorghum level in corn-sorghum flour mixtures and the classification of flour samples with high accuracy, a short analysis time, and no requirement for time-consuming sample preparation procedures. © 2020 Society of Chemical Industry.

Protein based evaluation of meat species by using laser induced breakdown spectroscopy

Meat adulteration through partial substitution with cheaper species or mislabeling causes significant problems in terms of health, religious beliefs, economy, and product quality. Therefore, identification of meat species is crucial for monitoring and prevention of meat fraud. In the present study, protein based laser induced breakdown spectroscopy method was developed for the first time to identify three meat species (beef, chicken and pork) by using bulk proteins and protein fractions, namely actin and myosin. LIBS spectra were evaluated with principal component analysis for clustering pattern of meat species, and partial least square analysis was performed to determine adulteration ratio. In PLS analysis, limit of detection (LOD) values for beef adulteration with chicken and pork meat were calculated as 2.84% and 3.89% by using bulk proteins, respectively.

Determination of milk fat authenticity in ultra-filtered white cheese by using Raman spectroscopy with multivariate data analysis

Cheese is one of the most widely consumed food products in the world. However, the increasing demand for nutritionally enhanced or functional products by the cheese industry has created new approaches that partially or fully replace milk fat. With this, new methods of adulteration have also been noted, potentially leading to these fully/partially-replaced products being offered as cheese. In this study, Raman spectroscopy was used to determine origins of fats in margarine, corn, and palm oils present in white and ultra-filtered cheese samples. Raman spectra were evaluated with partial least square-discriminant (PLS-DA) and PLS to identify fat/oil origins and adulteration ratios. The coefficients of determination and limits of detection for margarine, and corn and palm oil adulteration were found to be 0.990, 0.993, 0.991 and 3.38%, 3.36% and 3.59%, respectively.

Detection of Pistacia vera adulteration by using laser induced breakdown spectroscopy

BACKGROUND

Pistachio has high economic value because of its high consumption rate and consumer demand. Therefore, it has become an important target for adulteration. Green pea and spinach are the most frequently used foods for pistachio adulteration as a result of their kernel color. The present study aimed to detect pistachio adulteration with green pea and spinach samples using laser induced breakdown spectroscopy (LIBS) combined with chemometric methods.

RESULTS

In the first step of the study, principal component analysis was employed for qualitative analysis of pure pistachio, green pea, spinach and adulterated pistachio samples, and discrimination was achieved successfully. A score plot clearly discriminating pure pistachio, green pea and spinach samples, as well as their blind samples, was drawn using principle component (PC)1 and PC2 which explained 86.86% and 12.16% of the variance, respectively. The results showed that the calibration curve for green pea adulterated pistachio provides successful determination of adulteration level and had an R2 of 0.995 and a limit of detection (LOD) of 2.04%, whereas the calibration curve for spinach adulterated pistachio had an R2 of 0.993 and a LOD of 1.64%.

CONCLUSION

The results of the present study demonstrate that LIBS with the chemometric methods showed a good performance based on the high value of prediction accuracy for pistachio adulteration. This technique has high potential as a rapid method for pistachio identification and detection of adulteration. © 2018 Society of Chemical Industry.

Mineral content analysis of root canal dentin using laser-induced breakdown spectroscopy

OBJECTIVES

This study aimed to introduce the use of laser-induced breakdown spectroscopy (LIBS) for evaluation of the mineral content of root canal dentin, and to assess whether a correlation exists between LIBS and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) methods by comparing the effects of irrigation solutions on the mineral content change of root canal dentin.

MATERIALS AND METHODS

Forty teeth with a single root canal were decoronated and longitudinally sectioned to expose the canals. The root halves were divided into 4 groups (n = 10) according to the solution applied: group NaOCl, 5.25% sodium hypochlorite (NaOCl) for 1 hour; group EDTA, 17% ethylenediaminetetraacetic acid (EDTA) for 2 minutes; group NaOCl+EDTA, 5.25% NaOCl for 1 hour and 17% EDTA for 2 minutes; a control group. Each root half belonging to the same root was evaluated for mineral content with either LIBS or SEM/EDS methods. The data were analyzed statistically.

RESULTS

In groups NaOCl and NaOCl+EDTA, the calcium (Ca)/phosphorus (P) ratio decreased while the sodium (Na) level increased compared with the other groups (p < 0.05). The magnesium (Mg) level changes were not significant among the groups. A significant positive correlation was found between the results of LIBS and SEM/EDS analyses (r = 0.84, p < 0.001).

CONCLUSIONS

Treatment with NaOCl for 1 hour altered the mineral content of dentin, while EDTA application for 2 minutes had no effect on the elemental composition. The LIBS method proved to be reliable while providing data for the elemental composition of root canal dentin.

Identification of offal adulteration in beef by laser induced breakdown spectroscopy (LIBS)

Minced meat is the major ingredient in sausages, beef burgers, and similar products; and thus it is the main product subjected to adulteration with meat offal. Determination of this kind of meat adulteration is crucial due to religious, economic and ethical concerns. The aim of the present study is to discriminate the beef meat and offal samples by using laser induced breakdown spectroscopy (LIBS). To this end, LIBS and multivariate data analysis were used to discriminate pure beef and offal samples qualitatively and to determine the offal mixture adulteration quantitatively. In this analysis, meat samples were frozen and LIBS analysis were performed. The results indicate that by using principal component analysis (PCA), discrimination of pure offal and offal mixture adulterated beef samples can be achieved successfully. Besides, adulteration ratio can be determined using partial least square analysis method (PLS) with 0.947 coefficient of determination (R²) and 3.8% of limit of detection (LOD) values for offal mixture adulterated beef samples.

Laser-Induced Breakdown Spectroscopy Based Protein Assay for Cereal Samples

Protein content is an important quality parameter in terms of price, nutritional value, and labeling of various cereal samples. However, conventional analysis methods, namely, Kjeldahl and Dumas, have major drawbacks such as long analysis time, titration mistakes, and carrier gas dependence with high purity. For this reason, there is an urgent need for rapid, reliable, and environmentally friendly technologies for protein analysis. The present study aims to develop a new method for protein analysis in wheat flour and whole meal by using laser-induced breakdown spectroscopy (LIBS), which is a multielemental, fast, and simple spectroscopic method. Unlike the Kjeldahl and Dumas methods, it has potential to analyze a high number of samples in considerably short time. In the study, nitrogen peaks in LIBS spectra of wheat flour and whole meal samples with different protein contents were correlated with results of the standard Dumas method with the aid of chemometric methods. A calibration graph showed good linearity with the protein content between 7.9 and 20.9% and a 0.992 coefficient of determination (R²). The limit of detection was calculated as 0.26%. The results indicated that LIBS is a promising and reliable method with its high sensitivity for routine protein analysis in wheat flour and whole meal samples.

Determination of whey adulteration in milk powder by using laser induced breakdown spectroscopy

A rapid and in situ method has been developed to detect and quantify adulterated milk powder through adding whey powder by using laser induced breakdown spectroscopy (LIBS). The methodology is based on elemental composition differences between milk and whey products. Milk powder, sweet and acid whey powders were produced as standard samples, and milk powder was adulterated with whey powders. Based on LIBS spectra of standard samples and commercial products, species was identified using principle component analysis (PCA) method, and discrimination rate of milk and whey powders was found as 80.5%. Calibration curves were obtained with partial least squares regression (PLS). Correlation coefficient (R(2)) and limit of detection (LOD) values were 0.981 and 1.55% for adulteration with sweet whey powder, and 0.985 and 0.55% for adulteration with acid whey powder, respectively. The results were found to be consistent with the data from inductively coupled plasma - mass spectrometer (ICP-MS) method.

Efficacy of topical benzydamine hydrochloride gel on oral mucosal ulcers: an in vivo animal study

The aim of this study was to investigate the effect of benzydamine hydrochloride bioadhesive gel on healing of oral mucosal ulceration in an animal model. For in vivo determination of the effects of the bioadhesive gel, 36 rabbits were separated into three groups: the first group was treated with the gel formulation without active agent, the second group with the gel formulation containing benzydamine, and the third group received no treatment. Clinical healing was established by measuring the area of the ulcer in each test group on days 3, 6, 9 and 12. Histological healing was determined on the same days. Benzydamine containing gel applications resulted in a decrease in the ulcer area in 12 days (p=0.000). Histological evaluation showed that the benzydamine group had a higher mean histological score than the base and the control groups during the whole test period, and the difference between the benzydamine group and the control group was significant (p=0.04). The bioadhesive gel formulation of benzydamine hydrochloride showed a statistically significant increased rate of mucosal repair in this experimental standard mucosal wound animal study. It is a candidate for the topical treatment of oral mucosal ulcerative lesions.