Avaliação do estado oxidação dos óleos de abacate, azeite e arroz / Oxidation state evaluation of the avocado, olive and rice oils

O estado de oxidação é um importante aspecto relacionado à qualidade nutricional e sensorial dos óleos vegetais, que pode limitar a utilização dos mesmos. Assim, objetivou-se com este estudo avaliar o estado oxidação de óleo de abacate produzido nacionalmente, comparativamente a azeite de oliva extra virgem e a óleo de arroz refinado. Avaliaram-se nos produtos os índices de peróxidos, p-anisidina e coeficiente de extinção específica (K232 e K270). Os resultados indicaram que, de um modo geral, as amostras lipídicas mostravam bom estado de conservação, tanto em relação a produtos primários quanto secundários de oxidação. Entretanto, com base na legislação para azeite de oliva, pode-se inferir que o óleo de arroz apresentava elevado valor para produtos de oxidação secundários, expressos pelo K270. O óleo de abacate mostrou os mais baixos valores em todas as determinações realizadas, portanto, indicando estar em ótimo estado de conservação em relação à presença de produtos de oxidação.

Application of Fourier transform infrared spectroscopy for the quality and safety analysis of fats and oils: A review.

Fats and oils are essential food components. Their quality and safety pose major concerns for consumers and food producers because of factors such as oxidation and rancidity, excessive levels of trans fatty acid (TFA), and widespread adulteration. Thus, a rapid and easy-to-use technique must be exploited for quality parameter evaluation and monitoring to ensure the edibility, safety, and quality of fats and oils. In the last decades, Fourier transform infrared (FTIR) spectroscopy has shown great potential in analyzing fats and oils given its speed and simplicity. FTIR-based analytical techniques for common intrinsic quality parameters, including peroxide value, free fatty acid, moisture, TFA, iodine value, as well as oxidation stability, adulteration, and classification of various fats and oils, are summarized in this review. The advantages and disadvantages of selected infrared spectral accessories and sample preparation and spectral processing methods are highlighted. The prospects and reformative aspects for future application of the FTIR technique in the field of fats and oils are also discussed. This review may serve as a basis for applying FTIR not only in future research but also in the fat and oil industries.

The feasibility of multisectoral policy options aimed at reducing trans fats and encouraging its replacement with healthier oils in India.

INTRODUCTION: The World Health Organization recommends replacement of trans fat with polyunsaturated fat to reduce cardiovascular disease risk. Although several high-income countries have been successful in reducing trans fat in the food supply, low- and middle-income countries such as India may face additional contextual challenges such as the large informal sector, lack of consumer awareness, less enforcement capacity and low availability and affordability of healthier unsaturated fats. The objective of this study was to examine the feasibility and acceptability of multisectoral policy options aimed at supporting trans fat reduction and its replacement with polyunsaturated fats in India. METHODS: Multisectoral policy options examined in this study were identified using food supply chain analysis. Semi-structured interviews (n = 17) were conducted with key informants from agriculture, trade, finance, retail, industry, food standards, non-governmental organizations and the health professions to gain their views on the feasibility and acceptability of the policy options. Purposive sampling was used to identify key informants. Data were coded and organized based on key themes. RESULTS: There was support for policies aimed at improving the quality of seeds, supporting farmer co-operatives and developing affordable farming equipment suited to smallholders to improve the production of healthier oils. Increasing the role of the private sector to improve links among producers, processors and retailers may help to streamline the fats supply chain in India. Blending healthier oils with oils high in saturated fat, which are currently readily available, could help to improve the quality of fat in the short term. Improving consumer awareness through mass media campaigns and improved labelling may help increase consumer demand for healthier products. CONCLUSIONS: Reorienting agricultural policies to support production of healthier oils will help increase their uptake by industry. Policy coherence across sectors will be critical to reduce trans fat intakes and could be improved by increasing engagement among researchers, the private sector and government.

Terpenes as green solvents for extraction of oil from microalgae.

Herein is described a green and original alternative procedure for the extraction of oil from microalgae. Extractions were carried out using terpenes obtained from renewable feedstocks as alternative solvents instead of hazardous petroleum solvents such as n-hexane. The described method is achieved in two steps using Soxhlet extraction followed by the elimination of the solvent from the medium using Clevenger distillation in the second step. Oils extracted from microalgae were compared in terms of qualitative and quantitative determination. No significant difference was obtained between each extract, allowing us to conclude that the proposed method is green, clean and efficient.

Selectively improving the bio-oil quality by catalytic fast pyrolysis of heavy-metal-polluted biomass: take copper (Cu) as an example.

Heavy-metal-polluted biomass derived from phytoremediation or biosorption is widespread and difficult to be disposed of. In this work, simultaneous conversion of the waste woody biomass into bio-oil and recovery of Cu in a fast pyrolysis reactor were investigated. The results show that Cu can effectively catalyze the thermo-decomposition of biomass. Both the yield and high heating value (HHV) of the Cu-polluted fir sawdust biomass (Cu-FSD) derived bio-oil are significantly improved compared with those of the fir sawdust (FSD) derived bio-oil. The results of UV-vis and (1)H NMR spectra of bio-oil indicate pyrolytic lignin is further decomposed into small-molecular aromatic compounds by the catalysis of Cu, which is in agreement with the GC-MS results that the fractions of C7-C10 compounds in the bio-oil significantly increase. Inductively coupled plasma-atomic emission spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy analyses of the migration and transformation of Cu in the fast pyrolysis process show that more than 91% of the total Cu in the Cu-FSD is enriched in the char in the form of zerovalent Cu with a face-centered cubic crystalline phase. This study gives insight into catalytic fast pyrolysis of heavy metals, and demonstrates the technical feasibility of an eco-friendly process for disposal of heavy-metal-polluted biomass.

Metalworking fluid mist occupational exposure limits: a discussion of alternative methods.

NIOSH published a recommended exposure limit (REL) for metalworking fluids (MWF) in 1998 that was designed to prevent respiratory disorders associated with these industrial lubricants. The REL of 0.4 mg/m(3) (as a time-weighted average for up to 10 hours) was for the fraction of aerosol corresponding to deposition in the thoracic region of the lungs. This nonregulatory occupational exposure limit (OEL) corresponded to approximately 0.5 mg/m(3) for total particulate mass. Although this REL was designed to prevent respiratory disorders from MWF exposures, NIOSH acknowledged that exposures below the REL may still result in occupational asthma and hypersensitivity pneumonitis--two of the most significant respiratory illnesses associated with MWF. In the 8 years since the publication of the NIOSH MWF REL, neither the Occupational Safety and Health Administration (OSHA) nor the American Conference of Governmental Industrial Hygienists (ACGIH) has recommended an exposure limit for water-soluble MWF specifically, other than their previous exposure limits for mineral oil. An informal effort to benchmark companies involved in the manufacture of automobiles and automotive parts in North America indicated that most companies are using the NIOSH MWF REL as a guide for the purchase of new equipment. Furthermore, most companies have adopted a goal to limit exposures to below 1.0 mg/m3. We failed to find any company that has strictly enforced an OEL of 1.0 mg/m(3) through the use of either administrative controls or personal protective equipment, when engineering controls failed to bring the exposures to below this limit. We also found that most companies have failed to implement specific medical surveillance programs for those employees exposed to MWF mist above 1.0 mg/m(3). Organization Resources Counselors (ORC) published in 1999 (on their website) a "best practices" manual for maintaining MWF systems and reducing the likelihood of MWF-related illnesses. The emphasis of this approach was on control techniques, and there was no assignment of a specific OEL for MWF due to the wide variety of fluids that exist. The ORC did suggest that maintaining exposure levels to below 2.0 mg/m(3) would assist in minimizing upper respiratory complaints associated with MWF. Although the ORC manual indicated that MWF vary in composition and no single OEL is likely to be appropriate for all such fluids, it adopted a very similar concept to control banding, placing all MWF operations into a single band using similar (if not identical) controls. OSHA, in lieu of adopting a 6B health standard for MWF, has also published a voluntary "best practices" manual on their website. Their document drew heavily from the work of ORC and also incorporated information from the 1998 NIOSH MWF criteria document. Industrial users of MWF need to have guidance, such as an OEL, to determine when either engineering, administrative controls, or personal protective equipment must be implemented to protect their employees. The purpose of this article is to explore various approaches that might be taken to result in a single or multiple limits for exposures to MWF and its components. Approaches such as control banding are discussed in terms of an alternative to the use of an OEL.

Determination of acid number and base number in lubricants by Fourier transform infrared spectroscopy.

This paper describes the development of practical Fourier transform infrared (FT-IR) methods for the determination of acid number (AN) and base number (BN) in lubricants through the combined use of signal transduction via stoichiometric reactions and differential spectroscopy to circumvent matrix effects. Trifluoroacetic acid and potassium phthalimide were used as stoichiometric reactants to provide infrared (IR) signals proportional to the basic and acidic constituents present in oils. Samples were initially diluted with 1-propanol, then split, with one half treated with the stoichiometric reactant and the other half with a blank reagent, their spectra collected, and a differential spectrum obtained to ratio out the invariant spectral contributions from the sample. Quantitation for AN and BN was based on measurement of the peak height of the v(C = O) or v(COO) absorptions, respectively, of the products of the corresponding stoichiometric reactions, yielding a standard error of calibration of < 0.1 mg KOH/g oil. The AN/BN FT-IR methods were validated by the analysis of a wide range of new and used oils supplied by third parties, which had been analyzed by ASTM methods. Good correlations were obtained between the chemical and FT-IR methods, indicating that the measures are on the whole comparable. From a practical perspective, these new FT-IR methods have significant advantages over ASTM titrimetric methods in terms of environmental considerations, sample size, and speed of analysis, as well as the variety of oil types that can be handled. FT-IR analysis combining stoichiometric signal transduction with differential spectroscopy may be of wider utility as an alternative to titration in the determination of acid or basic constituents in complex nonaqueous systems.

[Comparison of methods to characterise thermally altered frying fats and oils]. / Methodenvergleich zur Charakterisierung thermisch veränderter Fritierfette und -öle.

During the process of deep fat frying the fat or oil undergoes several chemical and physical changes. To guarantee an effective quality control for used frying fats simple and rapid methods for the measurement of heat abuse are needed. Therefore several frying oils were heated with and without foodstuff and the change of polar parts, acid number, colour acid number, specific absorption and dielectric properties with prolonged heating time were determined. It could be shown that under usual frying conditions acid number and colour acid number, which are often used in praxis, as well as the specific absorption are not unrestrictedly useful to characterise heated frying fats. It turned out, however, that the determination of the dielectric properties with a foodoil-sensor is a useful tool to investigate heat abuse of frying fats and oils in routine analysis.

Regulating the use of degraded oil/fat in deep-fat/oil food frying.

During frying, the degradation of oil produces harmful compounds. Improper monitoring of oil-discard times in restaurants either risks the public health or causes financial losses to industries. Measuring the oil quality is a complex problem and an online sensor is needed. The process of frying reviewed includes moisture, heat and fat/oil transfer, crust formation and various structural, textural and chemical changes in the product, and degradation of frying medium. Some of the European nations and the U.S. have specific regulations against the use of deteriorated frying oils. Due to the absence of a suitable online frying oil quality sensor for restaurant situations, it is difficult to implement any regulation against the use of deteriorated frying oil. Based on various regulations, a model regulation to increase the safety and quality of fried foods is discussed. Background and requirements for developing an online sensor to measure frying oil quality are discussed. Other related areas reviewed in this article are factors affecting oil penetration and absorption by the food, surfactant theory of frying, analytical indices, quick tests and acceptability of frying oil.

Batch-swirl method for detoxification of isopropyl myristate used for sterility testing of oils and ointments: membrane selection.

A 1-hr batch-swirl method was developed for the preparation of isopropyl myristate to be used in the sterility testing of oils and ointments. The method is simpler and faster than that in USP XX. Flow rates of various membrane filters were tested. Cellulose acetate filters increased the filtration rate of oils and ointments and, thus, reduced the exposure time of possible microbial contaminants to the toxicity of isopropyl myristate.

[Production, control and use in swine of anti-foot-and-mouth disease vaccine in oil adjuvant]. / A propos de la production, du contrôle et de l'utilisation chez le porc du vaccin antiaphteux en adjuvant huileux.

A certain number of parameters involved in the manufacture, control and use of an efficacious vaccine against foot-and-mouth disease have been studied. This report considers the problems raised by the standardization of the raw material constituent to the vaccine as well as the different types of innocuity and activity testing carried out on sows, young pigs and bacon pigs. Special attention is given to virulence testing methods, to the criteria allowing evaluation of the quality of the vaccines and to the transmission of maternal immunity of the sows to their piglets and its incidence on the vaccination schedule.

Characteristics of prickly lettuce seed oil in relation to methods of extraction.

Samples of seed oil of prickly lettuce (Lactuca Sacriola oleifera) which had been obtained by pressing or by extracting with acetone, ethyl ether, petroleum ether or carbon tetrachloride were analysed for the following parameters: viscosity, saponification number, iodine number, thiocyanogen value, unsaponifiable matter, free fatty acids, peroxide number and fatty acid composition. The different parameters varied in part considerably in relation to the method of production (pressing or solvent extraction) and to the solvent. It is tried to interprete these relationships.

The effects of treatment with enzymatic preparations and tannin phenolic absorbent agents in extracting the olive oil by single pressure process on the oil yield, on the analytical characteristics of the oils of the vegetation waters and of the waste waters.

The vegetation waters of the must, the oils and the waste waters extracted from olive pastes, treated by enzymatic preparations (Cellulase, Hemicellulase, Polygalacturonase and Protease) and tannin phenolic adsorbent agents (Polyclar AT, Methylcellulose, Albumine) employed during crushing of olive were analysed:--the vegetation waters in order to justify some technological results (oil yields and extraction speed) obtained by the treatments;--the oils in order to examine the effects of the treatments on the same chemical characteristics and the stability to rancidity. --The waste waters to verify the possible influence of the treatments on the BOD. From the results relative to the vegetation waters, it has been suggested that the increase of the "detached oil" does occur by two different biochemical mechanisms which involve the constitutive lipoprotein of the oil drop membrane and colloidal constituents of the liquid and solid phase of the pastes. For what concerns the oils, the treatments induce the slight modification of the fatty acid composition and chromatic characteristics, a higher stability to rancidity, a qualitative and quantitative increase of the "headspace" violates constituents above oils. The waste waters obtained from the olive pastes show lower BOD5 values.

Physical characteristics of a new cleaning and polishing agent for use in a prophylaxips paste.

A prophylaxis composition containing a sodium-potassium aluminum silicate abrasive system was evaluated in the laboratory in comparison with several different commercial prophylaxis pastes. The in vitro data indicate that the new composition increases enamel polish and decreases abrasion characteristics without sacrificing cleaning efficacy when compared with the commercial products tested.