Evaluation of the quality of pet foods using fast techniques and official methods

This paper was designed to evaluate the rancidity of 18 pet food samples using the Diamed FATS kits and official AOCS methods for the quantification of free fatty acids, peroxide value and concentrations of malonaldehyde and alkenal in the lipid extracted. Although expiration dates have passed, the samples presented good quality evidencing little oxidative rancidity. The results of this study suggest that the Brazilian pet food market is replete with products of excellent quality due to the competitiveness of this market sector.

Evaluation of noni (Morinda citrifolia) volatile profile by dynamic headspace and gas chromatography-mass spectrometry

Noni is a fruit that has interested the scientific community due to its medicinal and functional activities. Different products that contain noni are already in the market, but their consumption could be impaired by their distinctive unpleasant aroma and flavor. The aim of this work was to evaluate the noni pulp volatile profile by dynamic headspace and gas chromatography-mass spectrometry. Thirty seven volatile compounds were detected, mainly alcohols (63.3%), esters (26.9%), cetones (7.4%), and acids (1.2%).

A method to determine volatile contaminants in polyethylene terephthalate (PET) packages by HDC-GC-FID and its application to post-consumer materials

A simple and low cost method to determine volatile contaminants in post-consumer recycled PET flakes was developed and validated by Headspace Dynamic Concentration and Gas Chromatography-Flame Ionization Detection (HDC-GC-FID). The analytical parameters evaluated by using surrogates include: correlation coefficient, detection limit, quantification limit, accuracy, intra-assay precision, and inter-assay precision. In order to compare the efficiency of the proposed method to recognized automated techniques, post-consumer PET packaging samples collected in Brazil were used. GC-MS was used to confirm the identity of the substances identified in the PET packaging. Some of the identified contaminants were estimated in the post-consumer material at concentrations higher than 220 ng.g-1. The findings in this work corroborate data available in the scientific literature pointing out the suitability of the proposed analytical method.

A fast and efficient method for the study of caffeine levels in energy drinks using micellar electrokinetic chromatography (MEKC)

Energy drinks are becoming popular in Brazil and in the world due to their stimulant properties. Caffeine is present in energy drinks with the aim of stimulating the central nervous system and intensifying brain activity. On the other hand, the ingestion of high doses of caffeine can cause undesirable symptoms such as anxiety and tachycardia. Therefore, it is necessary to monitor the caffeine content added to energy drinks to guarantee that the levels in the final product are in accordance with the labeling and within the legislation limits. The goal of this work was to validate a fast, efficient, and low-cost method for the determination of caffeine in energy drinks by micellar electrokinetic chromatography (MEKC). A total of seven brands were analyzed, each in three lots. The electrolyte was prepared with 50 mmol.L-1 of sodium dodecyl sulfate (SDS) and 10 mmol.L-1 of sodium carbonate (pH 11.0). The mean concentration of caffeine ranged from 122.8 to 318.6 mg.L-1. None of the brands had caffeine levels above the maximum limit. Considering the interval of confidence (95%), 72% of the samples had less caffeine than the amount informed on the product label.

Development and validation of a method for detection and quantification of ochratoxin A in green coffee using liquid chromatography coupled to mass spectrometry

A method using Liquid Chromatography Tanden Mass Spectrometry (LC-MS/MS) with matrix-matched calibration curve was developed and validated for determining ochratoxin A (OTA) in green coffee. Linearity was found between 3.0 and 23.0 ng.g-1. Mean recoveries ranged between 90.45% and 108.81%; the relative standard deviation under repeatability and intermediate precision conditions ranged from 5.39% to 9.94% and from 2.20% to 14.34%, respectively. The limits of detection and quantification were 1.2 ng.g-1 and 3.0 ng.g-¹, respectively. The method developed was suitable and contributed to the field of mycotoxin analysis, and it will be used for future production of the Certified Reference Material (CRM) for OTA in coffee.

Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee

Decaffeinated coffee accounts for 10 percent of coffee sales in the world; it is preferred by consumers that do not wish or are sensitive to caffeine effects. This article presents an analytical comparison of capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) methods for residual caffeine quantification in decaffeinated coffee in terms of validation parameters, costs, analysis time, composition and treatment of the residues generated, and caffeine quantification in 20 commercial samples. Both methods showed suitable validation parameters. Caffeine content did not differ statistically in the two different methods of analysis. The main advantage of the high performance liquid chromatography (HPLC) method was the 42-fold lower detection limit. Nevertheless, the capillary electrophoresis (CE) detection limit was 115-fold lower than the allowable limit by the Brazilian law. The capillary electrophoresis (CE) analyses were 30% faster, the reagent costs were 76.5-fold, and the volume of the residues generated was 33-fold lower. Therefore, the capillary electrophoresis (CE) method proved to be a valuable analytical tool for this type of analysis.

Characterization and extraction of volatile compounds from pineapple (Ananas comosus L. Merril) processing residues

The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%), followed by ketones (26%), alcohols (18%), aldehydes (9%), acids (3%) and other compounds (9%). Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.

Characterization and classification of pequi trees (Caryocar brasiliense Camb.) based on the profile of volatile constituents using headspace solid-phase microextraction - gas chromatography - mass spectrometry and multivariate analysis

In order to determine the variability of pequi tree (Caryocar brasiliense Camb.) populations, volatile compounds from fruits of eighteen trees representing five populations were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. Seventy-seven compounds were identified, including esters, hydrocarbons, terpenoids, ketones, lactones, and alcohols. Several compounds had not been previously reported in the pequi fruit. The amount of total volatile compounds and the individual compound contents varied between plants. The volatile profile enabled the differentiation of all of the eighteen plants, indicating that there is a characteristic profile in terms of their origin. The use of Principal Component Analysis and Cluster Analysis enabled the establishment of markers (dendrolasin, ethyl octanoate, ethyl 2-octenoate and β-cis-ocimene) that discriminated among the pequi trees. According to the Cluster Analysis, the plants were classified into three main clusters, and four other plants showed a tendency to isolation. The results from multivariate analysis did not always group plants from the same population together, indicating that there is greater variability within the populations than between pequi tree populations.

Optimization of image analysis techniques for quality assessment of whole-wheat breads made with fat replacer

The cellular structure of healthy food products, with added dietary fiber and low in calories, is an important factor that contributes to the assessment of quality, which can be quantified by image analysis of visual texture. This study seeks to compare image analysis techniques (binarization using Otsu’s method and the default ImageJ algorithm, a variation of the iterative intermeans method) for quantification of differences in the crumb structure of breads made with different percentages of whole-wheat flour and fat replacer, and discuss the behavior of the parameters number of cells, mean cell area, cell density, and circularity using response surface methodology. Comparative analysis of the results achieved with the Otsu and default ImageJ algorithms showed a significant difference between the studied parameters. The Otsu method demonstrated the crumb structure of the analyzed breads more reliably than the default ImageJ algorithm, and is thus the most suitable in terms of structural representation of the crumb texture.

Several techniques for the preparation of flour from carcasses of the Pantanal alligator (Caiman crocodilus yacare)

AbstractFlour prepared via current assay methodologies from the carcasses of the Pantanal alligator (Caiman crocodilus yacare) was analyzed for its chemical composition, minerals, fatty acids, and sensorial profile. Carcasses of the Pantanal alligator, originating from the Coocrijapan scientific zoo, Cáceres MT Brazil, were utilized. The carcasses were cooked for 60 minutes in a pressure cooker with water containing 2% salt and 5% chimichurri. The cooked carcasses were then ground and the mass was used for the manufacture of flour via three techniques: non-smoked, hot-smoked, and liquid-smoked. After each technique, the carcasses were dehydrated at 60ºC for 3h and were ground. Alligator flour was then produced. The moisture of liquid-smoked flour (10.97%) was higher than that of non-smoked flour (3.78%) and hot-smoked flour (4.43%). The flours provided high protein (57.11% - 58.27%) and ash (23.45 – 26.42%) rates, and were predominantly calcium (6.77% - 7.69%), phosphorus (3.67% - 4.05%), and iron (73.13 – 273.73 ppm/100 mg). Smoked-flour had a better acceptance rate by tasters when compared to non-smoked flour. Results show that flours produced from alligator carcasses had high protein, ash, and mineral rates and a reasonable acceptability by most tasters.

Construction of a supercritical fluid extraction (SFE) equipment: validation using annatto and fennel and extract analysis by thin layer chromatography coupled to image

Abstract The present work describes setting up a laboratory unit for supercritical fluid extraction. In addition to its construction, a survey of cost was done to compare the cost of the homemade unit with that of commercial units. The equipment was validated using an extraction of annatto seeds’ oil, and the extraction and fractionation of fennel oil were used to validate the two separators; for both systems, the solvent was carbon dioxide. The chemical profiles of annatto and fennel extracts were assessed using thin layer chromatography; the images of the chromatographic plates were processed using the free ImageJ software. The cost survey showed that the homemade equipment has a very low cost (~US$ 16,000) compared to commercial equipment. The extraction curves of annatto were similar to those obtained in the literature (yield of 3.8% oil). The separators were validated, producing both a 2.5% fraction of fennel seed extract rich in essential oils and another extract fraction composed mainly of oleoresins. The ImageJ software proved to be a low-cost tool for obtaining an initial evaluation of the chemical profile of the extracts.

Effects of different packaging techniques on the microbiological and physicochemical properties of coated pumpkin slices

Abstract In this study the effects of zein film coating along with benzoic acid on the quality of sliced pumpkin samples, which were packaged with different techniques were investigated. The samples were allocated into different groups and were treated with different processes. Following processing, the samples were stored at +4 °C for twenty days. Physicochemical and microbiological analyses were carried out on the samples once every five days during the storage period. According to color analysis, the L* value was observed to have significantly decreased in the processed and packaged samples in comparison with the control group. Besides, a* and b* values increased in all groups. It was determined that zein film alone did not exhibit the expected effectiveness against moisture loss in the samples. According to the results of microbiological analysis, a final decrease at approximately 1.00 log level was determined in total count of mesophilic aerobic bacteria (TMAB) in the group which was vacuum packaged in PVDC with zein coating when compared with the initial TMAB. Furthermore, no molding occurred in zein-coated group on the last day of the storage period, while massive mold growth was noted in the group which was packaged without any pretreatment procedure.

Accelerating food safety and quality control: The use of antibody engineering techniques in the detec-tion of low-molecular weight food contaminants

The increased awareness and evolved consumer habits have set more demanding standards for the quality and safety control of food products. The production of foodstuffs which fulfill these standards can be hampered by different low-molecular weight contaminants. Such compounds can consist of, for example residues of antibiotics in animal use or mycotoxins. The extremely small size of the compounds has hindered the development of analytical methods suitable for routine use, and the methods currently in use require expensive instrumentation and qualified personnel to operate them. There is a need for new, cost-efficient and simple assay concepts which can be used for field testing and are capable of processing large sample quantities rapidly. Immunoassays have been considered as the golden standard for such rapid on-site screening methods. The introduction of directed antibody engineering and in vitro display technologies has facilitated the development of novel antibody based methods for the detection of low-molecular weight food contaminants. The primary aim of this study was to generate and engineer antibodies against low-molecular weight compounds found in various foodstuffs. The three antigen groups selected as targets of antibody development cause food safety and quality defects in wide range of products: 1) fluoroquinolones: a family of synthetic broad-spectrum antibacterial drugs used to treat wide range of human and animal infections, 2) deoxynivalenol: type B trichothecene mycotoxin, a widely recognized problem for crops and animal feeds globally, and 3) skatole, or 3-methyindole is one of the two compounds responsible for boar taint, found in the meat of monogastric animals. This study describes the generation and engineering of antibodies with versatile binding properties against low-molecular weight food contaminants, and the consecutive development of immunoassays for the detection of the respective compounds.