Assessment of early harvest in the prevention of aflatoxins in peanuts during drought stress conditions.

The present study aimed to evaluate the effectiveness of early harvest in preventing aflatoxins in peanuts under drought-stress conditions. A field experiment was conducted on the 2018-2019 and 2019-2020 growing seasons in a greenhouse with an irrigation system to induce three drought stress conditions: no stress, mild, and severe stress. In addition, three harvest dates were proposed: two weeks earlier, one week earlier, and ideal harvest time. The mean peanut yield was 2634 kg/ha, considering the two growing seasons, and the drought stress conditions and harvest dates did not influence significantly. The shelling percentage was significantly higher in samples harvested at ideal harvest (77.7 %) than two weeks earlier (76.2 %) and was not influenced by drought stress conditions. Although a low mean percentage of grains with insect damage was identified, this percentage was statistically higher under severe stress (0.4 %) compared to no-stress conditions (0.2 %). The soil contamination ranged from 2.52 × 103 to 1.64 × 104 CFU/g of Aspergillus section Flavi, and the drought stress resulted in significantly higher concentrations in mild and severe stressed samples. A. section Flavi was found to infect all the peanut kernel samples. The drought stress resulted in higher percentages of A. section Flavi infections in samples from mild and severe stress conditions. The harvest date did not influence the soil and peanut kernel occurrence of A. section Flavi. A total of 435 and 796 strains of A. section Flavi were isolated from soil and peanut kernels, respectively. The potential of aflatoxin production by soil isolates was 31, 44, and 25 % for aflatoxin non-producers, aflatoxin B producers, and aflatoxin B and G producers, respectively, while in peanut kernel isolates were 44, 44, and 12 %. Three different A. section Flavi species were identified from peanut kernels: A. flavus, A. parasiticus, and A. pseudocaelatus. The mean aflatoxin concentration in peanut kernels was 42, 316, and 695.5 µg/kg in samples under no stress, mild stress, and severe stress conditions, respectively. Considering the harvest time, the mean aflatoxin concentration was 9.9, 334.3, and 614.2 µg/kg in samples harvested two weeks earlier, one week earlier, and in ideal harvest, respectively. In conclusion, the early harvest proved to be a viable, cost-free alternative for controlling aflatoxin in the peanut pre-harvest, resulting in a safer product and a better quality for sale and economic gain.

One-step rapid extraction of phytosterols from vegetable oils.

The conditions for the extraction of phytosterols (campesterol, stigmasterol and ß-sitosterol) from vegetal oils were optimized by means of response surface methodology (RSM). A 24 central composite rotatable design (CCRD) was used to investigate the effects of four independent variables: sample weight (g), saponification temperature (°C), saponification time (h) and number of extractions (n). The CCRD was carried out in 27 trials, including eight axial and three central points; and the response variables were the contents of campesterol, stigmasterol, ß-sitosterol and total phytosterols. The optimized conditions established by the RSM were 0.3 g of sample, saponification for 3 h at 50 °C and 4 extractions with n-hexane. Satisfactory values for linearity, recovery, repeatability, accuracy, precision, limits of detection (2.0-2.3 mg/100 g) and quantification (6.5-7.7 mg/100 g) were achieved. The optimized method was also validated by comparison with the official AOCS method, and the contents of stigmasterol and ß-sitosterol did not show significant differences (p > 0.05) when determined by both methods. However, low values (p < 0.05) for campesterol were found when the samples were analyzed by the AOCS method. The method optimized and validated in the present work is easy to carry out, fast and accurate. The method was successfully applied to sunflower, canola, corn, soybean and olive oils, and the lowest contents of total phytosterols were found in olive oil while and the highest amounts, in corn oil.

Acute and subacute oral toxicity assessment of dry encapsulated and non-encapsulated green coffee fruit extracts.

The coffee fruit is a high source of bioactive compounds such as phenolic acids and methylxanthines, comprising chlorogenic acids and caffeine, respectively. Extract from this matrix may be used as supplement or active ingredient of functional foods, energy drinks, cosmetics or drugs. Safety of caffeine- and chlorogenic acid-rich encapsulated and non-encapsulated hydroethanolic extracts from green coffee fruit (GCFE) was assessed by acute and subacute toxicity tests. In the acute test, oral single dosage until 1000 mg/kg per body weight (bw) did not show any adverse effect on both female and male mice according to the Hippocratic screening and clinical parameters for a period of 14 days. While the oral median lethal dose of non-encapsulated GCFE was 5000 mg/kg bw/day, that of encapsulated GCFE was not detectable likely due to the delayed release of caffeine and other compounds from GCFE. Non-encapsulated GCFE displayed a stimulating effect at a dose of 1000 mg/kg bw/day after 30 min of oral administration, but not after 60 min. Daily consumption of encapsulated GCFE for 30 days showed no adverse effect in male rats even at the highest dose. Extrapolating this value of no-observed-adverse-effect level (1000 mg/kg bw/day) to human consumption, a human equivalent dose of 189 mg/kg bw/day or 11.34 g/day could be estimated for encapsulated GCFE considering a 60 kg adult body weight.

Fat reduction and whey protein concentrate addition alter the concentration of volatile compounds during Prato cheese ripening.

The impact of fat reduction and the addition of whey protein concentrate (WPC) on the volatile compounds profile of Prato cheese was evaluated for 210 days of storage at 12 °C. Full fatPrato cheese, Prato cheese with fat reduction and reduced fatPrato cheese with 0.5% (w/v) WPC were made, and replicated on a different day. Cheese volatile compounds were extracted by solid phase microextraction (SPME) and separated, identified and quantified by gas chromatography coupled to a mass spectrometry detector (GC-MS). Fat reduction and the WPC addition resulted in lower concentrations of compounds derived from lipolysis and free fatty acid catabolism. Fat reduction generated higher levels of diacetyl and acetoin, both from the citrate metabolism, at days 5 and 30. A similar pattern was observed for sulfur compounds derived from the catabolism of free amino acids, at day 120. Higher levels of diacetyl (day15), dimethyl disulfide (days 150-180) and dimethyl trisulphide (days 150-210) were found for cheese with WPC. These differences might have occurred due to alterations in the structure and polarity of the protein matrix caused by fat reduction and the WPC addition.

Physical characteristics of the paper filter and low cafestol content filter coffee brews.

The results found in the literature concerning the effect of consuming filter coffee brews on increasing the blood cholesterol levels due to the presence of diterpenes, are divergent. Thus the present research evaluated the diterpene (cafestol and kahweol) concentrations in filter coffee brews prepared with paper filters of different sizes, colors and origins (Brazil, Japan, The United States of America, Germany, France and the Netherlands), with and without micro perforations. This is the first study that reports the physical characteristics of paper filter and its importance to obtain filter coffee brew with low cafestol content. Thus, a sample of Catuai cultivar coffee with high cafestol content was roasted to a medium-light degree and used to prepare the brews in a 1:10 ratio (coffee powder to water). The diterpenes were extracted by direct saponification and quantified and identified by HPLC-DAD-MS/MS. The paper filters were physically characterized by measuring their grammage, and the fat permeation rate calculated in order to better understand the differences between the filters which allow one to obtain higher or lower diterpene contents. The cafestol and kahweol concentrations in the brews varied from 1.62 to 2.98 mg/L and from 0.73 to 1.96 mg/L, respectively. The highest cafestol and kahweol concentrations were obtained using paper filters with micro perforations, considering similar sized paper filters. The paper filters showed high fat permeability and grammages between 50.46 and 67.48 g/m2. The diterpene retention capacities of the filters produced in the different countries were similar. The results showed that the porosity of the paper filter and the particle size of the ground roasted coffee were determinant factors in obtaining filter coffee brews with lower cafestol contents.

Whey Peptide-Iron Complexes Increase the Oxidative Stability of Oil-in-Water Emulsions in Comparison to Iron Salts.

Food fortification with iron may favor lipid oxidation in both food matrices and the human body. This study aimed at evaluating the effect of peptide-iron complexation on lipid oxidation catalyzed by iron, using oil-in-water (O/W) emulsions as a model system. The extent of lipid oxidation of emulsions containing iron salts (FeSO4 or FeCl2) or iron complexes (peptide-iron complexes or ferrous bisglycinate) was evaluated during 7 days, measured as primary (peroxide value) and secondary products (TBARS and volatile compounds). Both salts catalyzed lipid oxidation, leading to peroxide values 2.6- to 4.6-fold higher than the values found for the peptide-iron complexes. The addition of the peptide-iron complexes resulted in the formation of lower amounts of secondary volatiles of lipid oxidation (up to 78-fold) than those of iron salts, possibly due to the antioxidant activity of the peptides and their capacity to keep iron apart from the lipid phase, since the iron atom is coordinated and takes part in a stable structure. The peptide-iron complexes showed potential to reduce the undesirable sensory changes in food products and to decrease the side effects related to free iron and the lipid damage of cell membranes in the organism, due to the lower reactivity of iron in the complexed form.

Changes in the lipid fraction of king mackerel pan fried in coconut oil and cooked in coconut milk.

The influence of cooking on the nutritional value of king mackerel when cooked in coconut milk or pan fried in coconut oil was verified from the alterations in the fatty acid content; formation of cholesterol oxides and the nutritional quality indices of the lipids. Cooking in coconut milk caused an 11.6% reduction in the protein content and 28.3% reduction in the ash content. The lipid content increased after cooking (253%) and frying (198%) causing an increase in the caloric value. The total saturated and monounsaturated fatty acids of the cooked king mackerel increased 462% and 248%, respectively, whereas these increases were 418% and 130%, respectively, for the fried king mackerel. There were reductions of 21% and 38% in the total EPA+DHA of the pan fried and cooked samples, respectively, as compared to the fresh king mackerel. The heat treatment did not cause alterations in cholesterol content.

Is cafestol retained on the paper filter in the preparation of filter coffee?

Coffee brew presents sensory, stimulatory and antioxidant properties highly appreciated by consumers, despite being associated with an increase in the level of blood cholesterol due to the effects of the diterpenes, especially cafestol, present in the lipid fraction. Although it is believed that the paper filter retains the brew diterpenes, new studies have shown that sometimes coffee filtered through paper can also increase the blood cholesterol level, putting in doubt the efficiency of the paper filter in retaining the diterpenes. Thus the objective of the present study was to verify the distribution of cafestol between the paper filter, the spent coffee and the coffee brew itself, from two coffee samples containing high and low cafestol contents selected from 13 samples of different cultivars and from different locations. In addition, the effect of the roasting degree on the cafestol contents of the roasted coffee was evaluated and the relationship between particle size of the roasted coffee and the extraction of solids. The highest cafestol content was found in the lightly roasted coffee, and the coffee brew presented higher solids contents when the particle size of the coffee powder was below 500µm. The results showed that of the initial cafestol concentration present in the roasted coffee, the paper filter retained 12.41%, the spent coffee 87.45% and the brew 0.15%. Thus, one can conclude that the greater part of the coffee cafestol is retained by the spent coffee, due to the low extraction of the lipid fraction by the hot water.

Influence of salt on lipid oxidation in meat and seafood products: A review.

Sodium chloride, commonly known as salt, is a widely used additive in food industry due to its preservation and antimicrobial properties provided by its ability to reduce water activity. Moreover, the addition of salt to meat and seafood aims at improving water retention capacity and enhancing flavor due to its influence on the activity of some enzymes responsible for flavor development. On the other hand, salt added in meat and seafood can favor lipid oxidation, which is one of the main responsibles for quality losses in the food industry. In this review, the main mechanisms of fatty acids and cholesterol oxidation are described as well as the influence of salt on lipid oxidation in meat and seafood. Besides, the possible mechanisms of the pro-oxidant action of sodium chloride are presented and potential solutions to inhibit the salt action in lipid oxidation and decrease the salt content in food are discussed.

Microwave assisted direct saponification for the simultaneous determination of cholesterol and cholesterol oxides in shrimp.

A novel microwave-assisted direct saponification method for the simultaneous determination of cholesterol and cholesterol oxides in shrimp was developed and validated. Optimal saponification conditions, determined by means of an experimental design, were achieved using 500mg of sample and 20mL of 1mol/L KOH ethanol solution for 16min at 45°C at maximum power at 200W and magnetic stirring at 120rpm. Higher extraction of cholesterol oxides in a reduced saponification time (∼75 times) was achieved in comparison with the direct cold saponification method. The new method showed low detection (≤0.57µg/mL) and quantification (≤1.73µg/mL) limits, good repeatability (≤10.50% intraday and ≤8.56% interday) and low artifact formation (evaluated by using a deuterated cholesterol-D6 standard). Raw, salted and dried-salted shrimps were successfully analyzed by the validated method. The content of cholesterol oxides increased after salting and decreased after drying.

Inhibition of Cholesterol and Polyunsaturated Fatty Acids Oxidation through the Use of Annatto and Bixin in High-Pressure Processed Fish.

Annatto and bixin, the main carotenoid of annatto seeds, were both found to inhibit cholesterol oxidation in minced herring (Clupea harengus) and minced mackerel (Scomber scombrus) during high pressure processing (600 MPa for 10 min) and subsequent chilled storage for 2 wk, a treatment which otherwise increased the content of cholesterol oxidation products above a critical limit for human consumption. Annatto but not bixin reduced the loss of docosahexaenoic acid caused by high pressure processing of herring from 12% to 7%, an effect assigned to antioxidative effects of phenolic compounds in annatto, while bixin as a carotenoid binds to membranes protecting membrane cholesterol.

Influence of coffee genotype on bioactive compounds and the in vitro capacity to scavenge reactive oxygen and nitrogen species.

The influence of green coffee genotype on the bioactive compounds and the in vitro antioxidant capacity against the principal reactive oxygen (ROO(•), H2O2, HO(•), and HOCl) and nitrogen (NO(•) and ONOO(-)) species of biological relevance was investigated. This is the first report on the capacity of green coffee to scavenge H2O2, HOCl, and NO(•). Variations in the contents of total chlorogenic acids (22.9-37.9 g/100 g), cinnamoyl-amino acid conjugates (0.03-1.12 g/100 g), trigonelline (3.1-6.7 g/100 g), and caffeine (3.9-11.8 g/100 g) were found. Hydrophilic extracts of Coffea canephora and Coffea kapakata were the most potent scavengers of ROO(•), H2O2, HO(•), NO(•), and ONOO(-) due to their chlorogenic acid contents, which were, on average, 30% higher than those found in Coffea arabica and Coffea racemosa. The results showed that genotype is a determinant characteristic in the bioactive compound contents and consequently in the antioxidant capacity of green coffee.

Impact of chemical changes on the sensory characteristics of coffee beans during storage.

Sensory changes during the storage of coffee beans occur mainly due to lipid oxidation and are responsible for the loss of commercial value. This work aimed to verify how sensory changes of natural coffee and pulped natural coffee are related to the oxidative processes during 15 months of storage. During this period, changes in the content of free fatty acids (1.4-3.8 mg/g oil), TBARS values (8.8-10.2 nmol MDA/g), and carbonyl groups (2.6-3.5 nmol/mg of protein) occurred. The intensity of "rested coffee flavour" in the coffee brew increased (2.1-6.7) and 5-caffeoylquinic acid concentration decreased (5.2-4.6g/100g). Losses were also observed in seed viability, colour of the beans and cellular structure. All the results of the chemical analyses are coherent with the oxidative process that occurred in the grains during storage. Therefore, oxidation would be also responsible for the loss of cellular structure, seed viability and sensory changes.

New method for the extraction of volatile lipid oxidation products from shrimp by headspace-solid-phase microextraction-gas chromatography-mass spectrometry and evaluation of the effect of salting and drying.

A new method based on headspace-solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed, aimed at evaluating the formation of volatile lipid oxidation products (VLOPs) in shrimp during the salting and drying process. Of the four fibers evaluated, the fiber coated with divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) was the most adequate for the quantification of the VLOPs. The best analytical conditions were obtained by homogenization in an ultraturrax followed by extraction at 40 °C for 30 min. The optimized method allowed for the rapid and simple extraction of the VLOPs, with low detection (≤0.15 ng g(-1)) and quantification (≤0.50 ng g(-1)) limits and satisfactory precision (≤12.67%) and extraction efficiency (≥94.28%). The salting and drying negatively affected shrimp quality, reducing the fatty acid content and increasing the VLOPs, especially hexanal.

In vitro scavenging capacity of annatto seed extracts against reactive oxygen and nitrogen species.

Bixa orellana L. (annatto), from Bixaceae family, is a native plant of tropical America, which accumulates several carotenoids (including bixin and norbixin), terpenoids, tocotrienols and flavonoids with potential antioxidant activity. In the present study, the in vitro scavenging capacity of annatto seed extracts against reactive oxygen species (ROS) and reactive nitrogen species (RNS) was evaluated and compared to the bixin standard. Annatto extracts were obtained using solvents with different polarities and their phenolic compounds and bixin levels were determined by high performance liquid chromatography coupled to diode array detector. All annatto extracts were able to scavenge all the reactive species tested at the low µg/mL range, with the exception of superoxide radical. The ethanol:ethyl acetate and ethyl acetate extracts of annatto seeds, which presented the highest levels of hypolaetin and bixin, respectively, were the extracts with the highest antioxidant capacity, although bixin standard presented the lowest IC(50) values.

Effect of annatto seed and coriander leaves as natural antioxidants in fish meatballs during frozen storage.

UNLABELLED: The effects of annatto (0.1 g/100g) and coriander (0.5 g/100g) were assessed against lipid oxidation in white hake meatballs cooked in boiling water (95 ± 1 °C) for 30 min and stored at -18 °C for 120 d. The fatty acids (FA) and the nutritional quality, cholesterol, cholesterol oxides, thiobarbituric acid reactive substances (TBARS) values, and conjugated dienes were analyzed to follow the course of oxidation. Annatto and coriander were efficient in the control of lipid oxidation, also preserving the essential FA. At 120 d of storage, the eicosapentaenoic acid (EPA) concentration decreased respectively by 43%, 32%, 12%, and 9% in the control, coriander, annatto, and annatto + coriander patties. For docosahexaenoic acid (DHA), these concentrations decreased, respectively, 44%, 30%, 11%, and 7%, revealing a probable synergistic effect among the antioxidant compounds present in both spices. On the other hand, annatto and coriander were not able to act protecting the meatballs against lipid oxidation when they were cooked, also not exerted any effect in the cholesterol oxidation. PRACTICAL APPLICATION: Spices, especially coriander and annatto, can be an alternative to substitute synthetic additives with antioxidants to prevent loss of important unsaturated fatty acids (UFA) in fish meatballs during frozen storage for 120 d. The maximum effect was observed when 0.5% coriander and 0.1% annatto were used in combination. Cooking did not induce the formation of cholesterol oxides, compounds that can cause more health damages than cholesterol itself; however, during storage the cholesterol oxides levels presented a little increase regardless of spice addition.

Lipid and cholesterol oxidation in chicken meat are inhibited by sage but not by garlic.

UNLABELLED: The effects of the addition of sage and garlic in chicken meat on lipid and cholesterol oxidation, having as prooxidant factors the addition of salt, thermal treatment, and frozen storage, were evaluated. The content of unsaturated fatty acids did not change in the presence of sage; on the contrary, with garlic, the content of these fatty acids decreased after cooking and storage. Hexanal and pentanal contents were lower in patties containing sage, and higher in those with garlic. The 7-ketocholesterol was the cholesterol oxide found in higher amount in raw chicken on day 0, while the formation of 7ß- and 7α-hydroxycholesterol was verified only from day 30 on. Cooking and storage resulted in increase of total cholesterol oxides and decrease of α- and γ-tocopherol. Sage was effective in controlling lipid and cholesterol oxidation, minimizing the prooxidant effects of salt, cooking, and storage. However, garlic presented no effect as antioxidant and accelerated lipid oxidation. PRACTICAL APPLICATION: The addition of sage to chicken meat (0.1 g/100 g) is a good alternative to prevent and delay the formation of compounds derived from lipid oxidation that are responsible for off-flavors and loss of nutritional quality during long-term frozen storage. Care must be taken when using garlic to seasoning chicken meat products, such as hamburgers and meatballs, especially cooked or precooked due to its potential to promote lipid oxidation and consequently raising the risk of having the product rejected by the consumer.

Synthesis of 7-hydroperoxycholesterol and its separation, identification, and quantification in cholesterol heated model systems.

7-Hydroperoxycholesterol is considered to be an intermediate compound of the cholesterol oxidation path as the first product formed when cholesterol is oxidized by triplet oxygen. However, there is a limitation on cholesterol mechanism studies because of the lack of 7-hydroperoxycholesterol analytical standard due to its low stability. To verify the formation of hydroperoxides in cholesterol model systems heated at 140, 180, and 220 °C, 7α-hydroperoxycholesterol was synthesized by cholesterol photooxidation followed by rearrangement at room temperature in chloroform. Its structure was confirmed on the basis of 13C NMR and mass spectra obtained by APCI-LC-MS. The synthesized compound was also used as standard for the quantification of 7-hydroperoxycholesterol as the sum of 7α- and 7ß-hydroperoxycholesterol. The results demonstrated that 7-hydroperoxycholesterol is the first compound formed when the temperature is lower (140 °C). However, the concentration of the 7-hydroperoxycholesterol depends on the temperature and time of exposure: the higher the time, the higher the amount of 7-hydroperoxycholesterol at lower temperatures, and the lower the time, the lower the amount of 7-hydroperoxycholesterol at higher temperatures (180 and 220 °C). By the formation of 7-hydroperoxycholesterol, the known cholesterol oxidation mechanism in three phases (initiation, propagation, and termination) could be confirmed; once at lower temperatures, the stage of cholesterol oxidation is at initiation, at which hydroperoxide formation predominates.