Grilling Process Research Articles

Emission characteristics of particulate matter, odors, and volatile organic compounds from the grilling of pork

Meat-grilling restaurants are considered to be residential emission sources of air pollutants. To investigate the emission characteristics of particulate matter (PM), odors, and volatile organic compounds (VOCs) from the grilling of meat, a grilling apparatus equipped with butane gas burners was used to grill pork belly and marinated pork ribs in a laboratory setting. When grilling the pork belly, the emission factor for PM with a diameter of 2.5 μm or below (PM2.5) was 754 mg-PM·kg-meat−1, accounting for 99% of total suspended particles (TSPs), while that of the marinated pork ribs was 137 mg-PM·kg-meat−1 (96% of TSPs). Ammonia and acetaldehyde were the most common odors emitted during grilling at 43–88 mg·kg-meat−1 and 22–30 mg·kg-meat−1, respectively. Aldehydes were the most significant contributor to total odor intensity (36%–67%). Benzene, vinyl acetate, and hexene were the most abundant VOCs for the pork belly, while butane, vinyl acetate, and n-dodecane were the most abundant for the marinated ribs. Among the VOCs emitted from the pork grilling process, hexene, butane, and toluene were the dominant ozone precursors. The information obtained in this study is useful for furthering the understanding of the characteristics of air pollutants emitted from actual meat-grilling restaurants. Additionally, knowledge of the PM, odor, and VOC emission characteristics and their emission factors is useful for establishing management strategies for air pollutants from meat-grilling restaurants.

Fatty Acid Composition and Carotenoids in Raw and Grilled Tilapia GIFT Fillets Supplemented with Lycopene, β-Carotene and Lutein

This study evaluated the incorporation of β-carotene, lutein and lycopene into tilapia (genetically improved farmed tilapia, GIFT) fillets supplemented through 0, 20 and 40 days, and their influence on the fatty acid composition and nutritional quality of raw and grilled fillets. A control diet and a diet containing those carotenoids were elaborated with the same lipid source (soybean oil). For carotenoids analysis, the extraction was performed according to the literature, employing acetone and hexane. The relative intensities of m/z ratios of those carotenoids ions were obtained by ultraperformance liquid chromatography-tandem mass spectrometry with chemical ionization at atmospheric pressure (UPLC-APCI MS/MS), and an increase of carotenoid concentration in the supplemented fillets was observed, especially after the grilling process (180 oC for 15 min). An increase in the concentration of total carotenoids in grilled fillets (75 and 35% higher than raw fillets, for 20 and 40 days of supplementation, respectively, corresponding to 8.32 and 2.42 µg β-carotene g-1 sample) was also observed. Therefore, the carotenoids promoted the stability of lipid oxidation in grilled samples; fact that can be correlated with antioxidant effect of these compounds, it can be also explained by the breakdown of carotenoids physical barrier and the conditions used in the grilling process. Moreover, acceptable n-6/n-3 indices and recommended polyunsaturated fatty acids/saturated fatty acids (PUFA/SFA) values were observed in supplemented fillets. Consequently, lutein, β-carotene and lycopene were considered viable as additive on fish diet, since the supplementation promoted the increase of food quality, even after preparation for consumption.

Diet contains carcinogens and deficiency of vitamin C determines the level of oxidative DNA damage among Jakarta toll collectors

Consuming meat food products that undergo high-temperature combustion is able to provide opportunities exposed to carcinogenic substances and leads to oxidative stress. Oxidative stress is also a precondition for the occurrence of DNA damage and cancer can be detected by the presence of 8- hydroxy-'2-deoxyguanosine (8OHdG). The study aimed to investigate whether the high prevalence of oxidative stress in Jakarta highway toll collector is independently or causally implicated in deficiency of vitamin C and the grilled food as the third factor modified the association. A cross-sectional study and urinary 8-OHdG was detected using the Enzyme-Link Immunosorbent Assay (ELISA) method on 161 toll gate collectors. The study found a strong relationship between grilled food and 8-OHdG (p-value 0.037); prevalence risk ratio (PRR) 2.01 (95% CI 1.044-3.890). However, relationship between variable vitamin C and the 8-OHdG stratified by grilled food founded inverse negatively, it was due to the high frequency of subjects 8-OHdG presented significantly with the deficiency of vitamin C. There was not enough intake of vitamin C among people who ate grilled food. Mantel-Haenzel formula was calculated and the estimation found the condition of independence from the test were X2MH=0.843 among the group who consumed the grilled food. The association between intake of grilled food and oxidative stress is the mere result of the effect of deficiency of vitamin C. Special attention should be given to minimize diet containing various carcinogens like the meat grilling process with a high temperature to decrease degenerative diseases and cancer risk in sub-population with high expose to air pollution.

Production of biodiesel from food processing waste using response surface methodology

ABSTRACT The optimum conditions for biodiesel production by the transesterification of waste oil form the pork grilling process in the food factory in Udon Thani, Thailand, using NaOH and KOH as catalysts, has been investigated. A Box–Behnken Design (BBD) followed by a Response Surface Methodology (RSM) with 30 runs was used to assess the significance of three factors: the methanol to oil molar ratio, the amount of NaOH and KOH used, and the reaction time required to achieve the optimum percent fatty acid methyl ester (%FAME). The measured %FAME following transesterification using NaOH as a catalyst was an optimum 95.6% with a methanol to oil molar ratio of 12.2:1, a NaOH percentage mass fraction of 0.49% and a reaction time of 63 min. Using KOH as a catalyst, the %FAME was an optimum 93.0% with a methanol to oil molar ratio of 12:1, a KOH percentage mass fraction of 0.61% and a reaction time of 72 min. The coefficient of determination (R 2) for regression equations were 98.55% and 93.99%, respectively. The probability value (P<0.05) demonstrated a very good significance for the regression model. The physicochemical properties of the biodiesel obtained from the waste oil met the ASTM 6751 biodiesel standard, illustrating that waste oil from the pork grilling process can be used as a raw material for biodiesel production by transesterification.

Reduction of the polycyclic aromatic hydrocarbon (PAH) content of charcoal smoke during grilling by charcoal preparation using high carbonisation and a preheating step

ABSTRACTCharcoal-grilling may lead to contamination of food with carcinogenic polycyclic aromatic hydrocarbons (PAHs) during the grilling process. The objective of this work was to determine the effect of charcoal preparation on 16 USEPA priority PAHs in the smoke produced during the grilling process. Firstly, mangrove charcoal was prepared at carbonisation temperatures of 500, 750 and 1000°C. The charcoal were then preheated by burning at 650°C. This preheating step is usually used to prepare hot charcoal for the grilling process in the food industry. In this study, charcoal was preheated at different burning times at 5, 20 min and 5 h, at which time partial and whole charcoal glowed, and charcoal was completely burnt, respectively. Finally, PAHs in the smoke were collected and determined by GC/MS. The result showed that charcoal prepared at a carbonisation temperature of 500°C had higher levels of PAHs released into the smoke. In contrast, charcoal produced at 750 and 1000°C had lower PAHs released for all burning times. In addition, PAHs released for 5, 20 min and 5 h of burning time were about 19.9, 1.2 and 0.7 µg g−1 dry charcoal for charcoal produced at 500°C, and about 0.9–1.4, 0.8–1.2 and 0.15–0.3 µg g−1 dry charcoal for charcoal produced at 750 and 1000°C, respectively. Therefore, this research suggests that food grilled using charcoal carbonised at a high temperature of about 750°C presents a lower risk of PAH contamination. In addition, in the preheating step, whole charcoal should fully glow in order to reduce the PAH content in charcoal before grilling.

Influence of the cold storage time of raw beef meat and grilling parameters on sensory quality and content of heterocyclic aromatic amines

Heterocyclic aromatic amines (HAAs) are one of the most cancerogenic and mutagenic compounds present in food products. Thus, the researches on discovering new factors influencing formation of HAAs in food as well as the ways of reduction these compounds in food products are one of the main directions in food science. These investigations should led to the production of tasty food with significantly decrease content of HAAs. Unfortunately, there is no scientific research which are investigating the concentration of HAA together with the sensory properties of the products (e.g. grilled beef meat). The performance of the typical grilling process (180 °C and 280 °C) of beef meat (rib eye, sirloin and roast beef) stored in a raw state during 5 and 15 days in cooling condition and, than sensory evaluation and determination of correlation between overall sensory quality and content of HAA was the objective of presented study. This experiment confirmed that through proper selection parameters of culinary processing parameters such as thermal meat processing, the type of the culinary element of the beef meat and time of its storage in cooling conditions it is possible to ensure high overall sensory quality along with low content of HAA forming during grilling.

A model explaining and predicting lamb flavour from the aroma-active chemical compounds released upon grilling light lamb loins

The objective of the work is to understand the role of the different aroma compounds in the perception of the local “lamb flavour” concept. For this, a set of 70 loins (Longissimus dorsi) from approximately seventy day-old Rasa Aragonesa male lambs were grilled and the aroma-active chemicals released during the grilling process were trapped and analyzed. Carbonyl compounds were derivatizated and determined by GC-NCI-MS, whereas other aromatic compounds were directly analyzed by GC-GC-MS. Odour activity values (OAVs) were calculated using their odour threshold values in air. Lamb flavour could be satisfactory explained by a partial least-squares model (74% explained variance in cross-validation) built by the OAVs of 32 aroma-active chemical compounds. The model demonstrates that the lamb flavour concept is the result of a complex balance. Its intensity critically and positively depends to the levels of volatile fatty acids and several dimethylpyrazines while is negatively influenced by the different alkenals and alkadienals. (E,E)-2,4-decadienal and (E)-2-nonenal showed top OAVs.

Genotoxicity and Histopathological Studies on the Liver, Kidney and Lymphocytes of Male Rats Fed on Diet Containing Waste Fat Released from Chicken During Grilling Process

Fat released from chicken during grilling process, as waste, is used by some low income people in Egypt in cooking as dietary fat because it is a cheap fat source compared to other fats. The present study aimed to elucidate the genotoxic and histopatholgic effects of grilled chicken fat on the liver, kidney and lymphocytes of male albino rats. Fifteen two months old male rats were divided to three groups, the first group was fed on control diet, the second and third groups were fed diets containing wasted fat at substitution levels of 50 and 100% from the fat of diet, respectively. The animals were fed ad-libtium for eight weeks. The single cell gel electrophoresis (Comet) assay is a simple and effective method for detecting DNA damage in control and treated rat cells, and results showed significant increase in tailed nuclei (DNA damage), tail moment , % DNA in the tail and tail length in liver , kidney and lymphocytes of treated groups compared to the control.In addition, both liver and kidney of treated rats showed a marked degenerative changes congestion of blood vessels in addition to loss of protein, polysaccharides and DNA content.

Analysis of the Color Change in Fish during the Grilling Process

Samples of red sea bream (Pagrus major), a white-meat fish, were grilled under an infrared heater, and the temperature and color of the sample surface was measured. For the change in color, brightness component L* and two chromatic components a*(from green to red) and b*(from blue to yellow) were measured. As the browning reaction proceeded, L* decreased monotonously and a* and b* varied in a complex way; however, a* and b* were correlated with L*. The browning reaction was treated as a first-order reaction and it was assumed that L* decreased in proportion to the reactive product. The reaction rate constant of the diminution rate of L* was determined to be in agreement with the values obtained from the experiment in which sample temperatures were maintained at a certain level. The estimated values of L*, a*, and b* were in good agreement with experimental values.

Nutritional, biochemical and cytogenotoxicity studies on wasted fat released from chicken during grilling process

Some physico–chemical properties of fat released from chicken during grilling process were evaluated and the results showed that refractive index and saponification values were not affected by grilling process. However, serious increases in oxidative deterioration parameters and color were noticed. The main objective of this study was to characterize the effect of grilled fat on body weight, liver function, chromosomal aberrations and micronucleus formation in rats. Eight-week-old Swiss male albino rats, weighing approximately 90g were used in this study. Rats were fed on a diet containing grilled fat for two months showed insignificant decrease in body weight compared to the control except, the eighth week (last weighing). The serum analysis should that aspartate transaminase (AST), cholesterol, creatinine and urea levels increased significantly whereas, alanine transaminase (ALT), and triglyceride levels were not affected. Also, cytogenetic analysis showed various types of chromosomal aberrations, i.e., chromatide breaks, ring chromosome, fragment chromosome, and end to end association chromosomes and insignificant increase in the frequency of micronucleated cells.

Effect of grilling process on antibiotic residues in edible tissues of poultry by FPT method

Regarding to vast application of the antibiotic drugs in animals quality control of food stuff, from point view of not containing antibiotic residues, is necessary. Existing of antibiotic residues in food stuff, especially meat, and their transference to the body of consumer, is the cause of effects like bacterial resistance, allergic reactions, toxicity, carcinogenic effects and disturbing of natural micro flora of intestine. This paper presents the net change by grilling on residues of antibiotics in edible tissues of poultry. Four-plate test is one of the microbiologic methods for detecting antibiotic residues in food stuff, which is at the base of inhibition zone formation around the sample in four culture media with different pH and test bacteria. For this purpose, 40 carcasses were collected on each of eight visits from Tabriz poultry slaughtering houses. Four locations were sampled aseptically from each carcass: breast muscle; skin; liver and gizzard. After doing different phases of four-plate test on raw samples , from total 40 muscle samples, 25 cases (62/5%); from total 40 liver samples, 40 cases (100%); from total 40 skin samples, 21 cases (52/5%) and from total 40 gizzard samples, 15 cases (37/5%) are diagnosed to be polluted to antibiotic residues. Then positive samples incubated in 200 °C. incubation time regarding to usual cooking time were as follows: muscle 40 min; skin 15min; liver 25 min; gizzard 60 min then we perused samples by FPT method again for present of antibiotic residue and non of the positive raw samples have any residue of antibiotics after grilling (P< 0.05). Therefore enough cooking temperature & time can have a great effect on antibiotics residues in food.

Growth of Yersinia enterocolitica in Inegol meatballs.

Our results demonstrate that more importance should be given to the hygienic conditions during the production of the Inegol meatballs and that efficient grilling process should be applied when preparing the meatballs.

Effect of two methods of grilling on the oxidative rancidity and cholesterol oxidation in beef and chicken shawerma

The effect of direct blue and charcoal radiation heat grilling on the oxidative rancidity of fat and cholesterol oxidation in beef and chicken shawerma was studied during the first 3 hours of grilling process. The oxidative rancidity of the fat was measured by thiobarbituric acid value (TBA), while that of cholesterol by evaluating the concentration of 7-ketocholesterol. No significant effect (p≤ 0.05) of the source of the grilling radiation heat was found on TBA values or 7-ketocholesterol content. The degree of unsaturation of the fat had significant effect (p≤0.05) on TBA and 7-ketocholesterol values. TBA values and 7-ketocholesterol for both samples grilled either by direct blue or charcoal radiation heat reached maximum values after 30 min of the heat treatment then they remained relatively constant throughout the rest time of the experiment.

Determination of heterocyclic amines in flame-grilled fish patty by capillary electrophoresis.

A simple and reliable capillary zone electrophoretic (CZE) method for quantifying mutagenic and carcinogenic heterocyclic amines (HCAs) in cooked foods with UV-visible diode-array detection is described. The buffer system consisted of 50 mM disodium hydrogen phosphate, 30 mM sodium chloride, 20 mM citric acid and 26% methanol at pH 2.1. An uncoated silica tubing, 51 cm in length, was used for the CZE separation. The capillary tubing temperature was maintained at 25 degrees C with a constant voltage of 20 kV. The reproducibility of the method was over 95% for a five-replicate analysis of 10 micrograms/l-spiked 2-amino-3,4,7,8-tetramethylimidazo[4,5-f]quinoxaline (4,7,8-TriMeIQx) and the detection limit was in the low microgram/l range with coefficients of variation between 6 and 18%. An analytical run took only 15 min for 12 known HCAs. Using this procedure, up to 30 samples could be analysed in a single day. The method is reliable and can be used for screening of various HCAs. It has been applied to assess the concentrations of heterocyclic amines in otak-otak, a Malay-style grilled fish patty. The major mutagenic contaminant found in this foodstuff was 2-aminodipyrido[1,2-a:3',2'-d]imidazole (Glu-P-2) (286-1068 micrograms/kg), followed by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (1.6-13.0 micrograms/kg) and 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) (14.0-87.5 micrograms/kg). Two co-mutagens norharman (NH) and harman (H) were also detected in otak-otak at levels of 2.0-13.0 micrograms/kg and 12.8-21.3 micrograms/kg, respectively. The substantial amount of Glu-P-2 detected in otak-otak is probably a result of the ingredients used and the high temperature grilling process.