Cooking Procedures Research Articles

Quantification of the Aluminum Content Leached into Foods Baked Using Aluminum Foil.

In this study, determinations of the aluminum content in meat and fish performed after having cooked these foods using commercially available aluminum foil have been performed. The release of this chemical element was evaluated by cooking beef, chicken, and fish wrapped with commercial aluminum foil using seasoning or without seasoning in order to evaluate the effect on Al leaching into the food. The characterization of the food samples was carried out using two different analytical methods: inductively coupled plasma optical emission spectrometry (ICP-OES), for the quantification of aluminum, and scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS) to evaluate any structural changes occurring inside the aluminum foil after the cooking procedure. It has been demonstrated that the leaching that occurs when the foods are cooked by wrapping them in Al foil is not negligible and that the consumption of these foods, together with the consumption of other foodstuffs, such as, for example, some vegetables that may naturally contain aluminum, can lead to consuming a weekly dose not far from the TWI (tolerable weekly intake).

Effect of parboiling on toxic metal content and nutritional composition of three rice varieties locally produced in Nigeria

Parboiling of rice is a common cooking method and its effect on quality of rice is sparse in the existing literature. The current study was designed to evaluate the effect of parboiling on levels of nutritional components and toxic metals of rice locally produced and consumed in Nigeria. Three varieties of rice were considered and each sample divided into two portions for parboiling and conventional cooking procedures using standard methods. The rice flours were prepared for proximate analysis, amino acid and vitamin profiles using HPLC, while minerals and toxic metals were analyzed by inductively-coupled plasma optical emission spectrometry (ICP-OES). Parboiling significantly (p<0.05) increased ash and fiber contents of the rice samples, whereas, lipids considerably (p<0.05) reduced compared to the unparboiled rice. The levels of some of the essential amino acids, vitamins were significantly reduced by parboiling. Parboiling markedly (p<0.05) reduced levels of aluminium, nickel, chromium and manganese; cadmium, lead and arsenic levels were however increased significantly by parboiling. This study reveals that parboiling may significantly affect components of cooked rice and exert impact that may alter health status. Future studies are suggested to clarify further the effect of parboiling on toxic metals in staple food like rice.

Investigation of the Adsorption Behavior of Jet-Cooked Cationic Starches on Pulp Fibers.

The optimization of the thermal treatment of cationic starch in the paper industry offers the opportunity to reduce the energy consumption of this process. Four different industrially relevant cationic starches, varying in source, cationization method and degree of substitution were treated by a steam-jet cooking procedure, comparable to industrially employed starch cooking processes. The influence of the starch properties and cooking parameters on the adsorption behavior of the starches on cellulosic pulp was investigated. The adsorbed amount was affected by the cooking temperature and the type of starch. For some starch grades, a cooking temperature of 115 °C can be employed to achieve sufficient starch retention on the pulp fibers. The energy consumption could further be reduced by cooking at higher starch concentrations without loss of adsorption efficiency.

Quantification of Allyl Methyl Sulfide, Allyl Methyl Sulfoxide, and Allyl Methyl Sulfone in Human Milk and Urine After Ingestion of Cooked and Roasted Garlic.

Due to its characteristic flavor and positive effects on human health, garlic is a highly valued food ingredient. Consumption of garlic alters the quality of body odors, which may in some instances hinder social interaction but be beneficial in other contexts, as it is assumed to contribute to early flavor learning in the breastfeeding context, for example. In previous work, allyl methyl sulfide (AMS) has been identified as the major odor-active metabolite in urine and milk, being excreted together with the odorless metabolites allyl methyl sulfoxide (AMSO) and allyl methyl sulfone (AMSO2) after ingestion of raw garlic. The present work aimed to elucidate whether commonly used culinary thermal processing steps influence the excretion profiles of garlic-derived compounds. To this aim, urine (n = 6) and milk (n = 4) samples were donated before and after ingestion of roasted and cooked garlic and investigated by gas chromatography-olfactometry/mass spectrometry, and, in the case of milk, by aroma profile analysis. The concentrations of AMS, AMSO, and AMSO2 were determined by stable isotope dilution assays. Sensory evaluations revealed that a garlic-like odor was perceivable in milk samples donated after ingestion of roasted and cooked garlic. Besides AMS, AMSO, and AMSO2, no other odor-active or odorless compounds related to the ingestion of roasted or cooked garlic were detected in the urine and milk samples. Maximum concentrations of the metabolites were detected around 1–2 h after garlic intake. In some cases, a second maximum occurred around 6 h after ingestion of garlic. The cooking procedure led to a more important reduction of metabolite concentrations than the roasting procedure. These findings suggest that intake of processed garlic leads to a transfer of odor-active and odorless metabolites into milk, which contributes to early flavor learning during breastfeeding and may also have a physiological effect on the infant.

Decontamination of aflatoxin B1 in peanuts using various cooking methods.

Peanut and its processed products are recurrently contaminated with aflatoxins (AFs) which are of potential public health concern. Among the different types of AFs, Aflatoxin B1 (B1) is the most frequently detected in peanuts over the maximum level (ML),and thus has warranted considerable research interest in the domain of food safety. In this study, we investigated the decontamination of B1 in three naturally-incurred lots (4, 12, and 40µg/kg)of peanuts bya range of cooking treatments, including frying, pressure cooking, and roasting.B1 concentrations were determined by ultra-high performance liquid chromatography- fluorescence detection. The method provided a limit of quantification of 0.25µg/kg for B1, which was much lower than any of its national and internationalMLs.The recoveries of B1 in fresh and cooked peanuts (positive-control) werein the range of 90-100%. Overall, all the cooking methods demonstrated a significant reduction in B1 loads.The degree to which theprocessing methods reducedthe B1 content followed the pattern: roasting with a combination ofNaCl and citric acid > pressure-cooking with a combination ofNaCl and citric acid > frying.As the cooking procedures did not involve any complicated steps or sophisticated equipment, these could be readily adopted for decontamination orreductionin the level of B1 for a safer consumption of peanuts at the household level without affecting the organoleptic properties.

Identification of fluorescent nanoparticles from roasted sweet potato (Ipomoea batatas) during normal cooking procedures

Fluorescent nanoparticles (FNs) were identified from roasted sweet potato with a particle size of 7.0, 2.8, 2.4 nm for peel FNs, and 2.3, 1.9, 2.2 nm for pulp FNs after roasting at 250 °C for 20, 40, and 60 min, respectively. Blue fluorescence of FNs was observed under ultra-violet light excitation. The fluorescence intensity of the FNs increased when they were transferred from acidic to alkaline environment, and the FNs showed good photostability. The fluorescence of peel and pulp FNs was quenched 42.65% and 35.59%, respectively, in vitro digestion. The FNs could be absorbed by the digestive tracts of mice and enter liver, heart, kidney, brain, lung and testis. A distinct interaction between FNs and dopamine was confirmed in weakly alkaline aqueous solution. This work provided useful information in understanding the property of FNs generated in plant-based food of roasted sweet potato during normal cooking.

Study of the incorporation of native and microencapsulated chia seed oil on pasta properties

SummaryThe present work studied the effect of the incorporation of encapsulated chia seed oil on the cooking quality of dry pasta. Pasta morphology and oil distribution in the samples were studied. No significant variations were determined in cooking parameters as optimal cooking time, cooking loss and texture of cooked pasta with the incorporation of the encapsulated oil, but significant differences were determined in uncooked pasta texture and variables that describe water interaction, such as water absorption and swelling index. In addition, the incorporation of microencapsulated oil avoided oxidative deterioration, showing a protective effect and preventing the formation of hydroperoxide radicals in pasta preparation, storage and cooking procedures (compared with free oil‐containing pasta), resulting in a safer product. Storage at modified atmosphere exerts an additional protective effect on oil, enhancing the effect of the microcapsules. Microencapsulation proved to be an effective technology that preserves oil quality in ω‐3 rich pasta.

137Cs, 40K, and K in raw and stir-fried mushrooms from the Boletaceae family from the Midu region in Yunnan, Southwest China

The parallel batches of the same species and geographical origin mushrooms both raw and stir-fried were investigated to get an insight into the content and intake of 137Cs, 40K, and K from mushroom meals. The Boletaceae family species (Baorangia bicolor, Boletus bainiugan, Butyriboletus roseoflavus, Retiboletus griseus, Rugiboletus extremiorientalis, and Sutorius magnificus) were collected from the Midu County (Dali Bai Autonomous Prefecture) in 2018. The activity concentrations of 137Cs in the caps of dried raw mushrooms were in the range 14 ± 1 Bq kg−1 dry biomass (db) (R. griseus) to 34 ± 2 Bq kg−1 db (R. extremiorientalis), and in stems from 16 ± 1 Bq kg−1 db (B. bicolor and B. bainiugan) to 23 ± 1 Bq kg-1 db (R. extremiorientalis). The mean activity concentration in the whole fruiting bodies in all six species was 18 ± 4 Bq kg-1 db. The activity concentrations of 137Cs were roughly the same in both dehydrated materials, stir-fried, and raw mushrooms, while the contents of 40K and stable K were around 2- to 3-fold smaller in stir-fried than raw product. The raw and stir-fried mushrooms on a whole (wet) weight basis showed activity concentrations of 137Cs in the range from 1.2 to 3.2 Bq kg−1 ww (mean 1.9 ± 0.6 Bq kg−1 ww) and 6.0 to 9.4 Bq kg−1 ww (mean 7.0 ± 1.2 Bq kg−1 ww), respectively. Evidently, when expressed on a whole (wet) weight basis, the cooked mushrooms showed on average around 3.5-fold greater activity concentration of 137Cs when compared with raw mushrooms. The 137Cs, 40K, and total K enrichment in stir-frying (in a whole (wet) weight basis for the meal), confronted with the results for dehydrated raw and fried mushrooms, show the direct correlation with loss of mass (largely moisture) during the cooking procedure but not much of 137Cs and 40K. Edible wild mushrooms from Yunnan were little contaminated with radiocaesium. As assessed, the mean radioactivity dose from natural 40K in around 9.3-fold exceeded the dose obtained for artificial 137Cs from stir-fried mushroom meals, which both were very low doses.

Comparative analysis of the texture and physicochemical properties of cooked rice based on adjustable rice cooker

Increasing demands for better palatability of cooked rice is driving innovations in cooking control of rice cooker. Cooking procedure is the core of rice cookers. To fully understand the differences of different rice procedures, the cooking curves of 12 rice cookers were acquired and analyzed by pattern recognition methods in this study. The results suggested that the initial heating stage (0–1400 s) was the major factor affecting the hardness and stickiness of the cooked rice. Meanwhile, the effect of heating rate on the texture of cooked rice was verified using a power-regulated rice cooker that the lower heating rates led to lower hardness (from 3608.2 g to 2692.9 g), stickiness (from 385.8 g s to 282.4 g s), and viscoelastic (from 0.05 to 0.06 to 0.08–0.09) of the cooked rice. The gelatinization temperatures of starch increased with heating rate, while the enthalpy increased firstly (2.22 J/g to 4.76 J/g) and then decreased (4.76 J/g to 2.96 J/g). Proton distribution in rice cooked at different heating rates was found responsible for the varied distribution and combination state of water in rice. These results indicated that the structural transformation of kernel were varied at different heating rates.

Quantitative Instrumental Assessment of Cooked Rice Stickiness

Stickiness is a major textural characteristic of cooked rice and an important criterion in cultivars classification. Many reports on instrumental evaluation cooked rice stickiness are based on variants of the texture profile analysis (TPA), a method that has fundamental methodological flaws and creates logical inconsistencies. Notable among these is that cooked rice tested as a flat cylindrical specimen having a larger diameter is always harder and stickier than when tested as a narrower specimen. Recent novel improvements have been the use of a universal testing machine (UTM) to record the force and calculate the work needed to separate a pre-compressed pair of individual cooked rice kernels, or to separate a single pre-compressed cooked kernel from the flat surface to which it is attached, while accounting, in both cases, for the contact areas. It is proposed to modernize an older manual method to measure the attractive force between two uncompressed cooked rice kernels directly with a tensiometer by replacing it with a UTM and expressing the result in term of a cohesion index, the dimensionless ratio between the net separation force and an individual cooked kernel’s weight. Rough calculations based on published data indicate that cooked rice of cultivars known to be sticky would have an index on the order of 15 while those known as non-sticky about 3 only, where the actual values will depend on the cooking procedure and the dry rice’s history. Also proposed is a similar adhesion index to characterize the attractive interaction of cooked rice with any surface of interest.

The Effect of a Short Message-Based Nutrition Education Intervention on Employees’ Knowledge and Practice in Terms of Adopting the Methods of Inhibition of Polycyclic Aromatic Hydrocarbons Formation in the Cooked Meat

The present study was undertaken to examine the effect of a short message-based (SMS) nutrition education intervention on the employees’ knowledge and practice in terms of adopting the methods of inhibition of the formation of Polycyclic Aromatic Hydrocarbons (PAHs) in the cooked meat. The quasi-experimental study was conducted among 128 employees at Iran University of Medical Sciences, Tehran, Iran, during May 2017–Jan 2018. One faculty was randomly assigned to a control group and the other was assigned to an intervention group. Then, 64 employees of each faculty were randomly selected. Information (data) was collected by a questionnaire. Information (data) regarding knowledge and practice regarding the methods of inhibition of PAHs formation in the cooked meat was collected by a researcher-made questionnaire. Twenty six short messages were designed and sent to the participants’ phones in the intervention group during the 26-day intervention period. Two groups were followed-up two months after the intervention delivered via SMS. Following the intervention delivered via SMS, there were significant differences in the participants’ knowledge and also their practice regarding the methods of controlling cooking procedure for the inhibition of PAHs formation in the cooked meat in the intervention group compared to the control group. In addition, there was no significant difference in the meat preparation techniques used between the groups after the intervention. Developing SMS-based interventions may improve the knowledge and practice of the individuals to control the cooking procedure to prevent/reduce PAHs in the cooked meat.

Influence of feeding systems on Chemical Contents and Sensory Quality of Longissimus thoracis Lamb Muscle cooked in boil and grill

Nutritive and sensory characteristics of the lamb meat depend not only on breeding conditions and systems but also on cooking procedures. The aim of this study was to evaluate the effect of two cooking methods on the nutri-tional and sensory quality of L. thoracis meat from lambs reared in two Alge-rian systems. The lambs grazed either in a highland pasture with a hay sup-plementation, or in a steppe pasture with concentrate supplemention. After three months of grazing, all the lambs from both rearing systems were slaughtered, and eviscerated in a local commercial slaughterhouse. The dis-sected muscles were trimmed, minced in a meat grinder and analysed. Grill-ing and broth cooking were respectively performed at 250°C and 100°C for 30 min. The obtained results indicated that cooking methods had a signifi-cant effect (p &lt;0.05) on all the analyzed parameters. It appeared that fat, water loss and thiobarbituric acid reactive substances (TBARS) values of the samples increased with cooking procedure. Overall, cooking increased total saturated and polyunsaturated fatty acid contents of the intramuscular lipid (p&lt;0.05) while reducing the n-6/n-3 ratio (p&lt;0.001). The results reported on the color analysis indicated significant difference for the red index (p&lt;0.05) which was more predominant in the Steppe fed lamb muscle than in the highland one (14.05 vs. 8.01, respectively). Changes in a* values appeared to be affected by lipid oxidation and are strongly correlated with thiobarbituric acid reactive substances (TBARS) values. Finally, although cooking results in an increase in the lipid oxidation of meat, its nutritional and dietary value is not impaired. It seems that the Algerian rearing systems is an interesting for outdoor sheep breeding and allow to obtain a meat preserving a healthy nutritional quality after cooking.

Cowpea storage under nitrogen‐modified atmosphere at different temperatures: Impact on grain structure, cooking quality, in vitro starch digestibility, and phenolic extractability

Cowpeas were stored for 12 months under a nitrogen-modified atmosphere at 15, 20, and 25°C. Cowpeas analyzed immediately, without subjection to the storage period, constituted the initial sample. Long-term storage promoted changes in the cooking characteristics of the cowpeas as a result of a rigidized cotyledon structure. Hardened cowpeas exhibited lower percentages of starch hydrolysis. Even under nitrogen-modified storage, the higher temperatures of 20 and 25°C favored the structural alterations that hampered the enzymatic digestion of starch. The changes were minimal at 15°C, indicating that the combination of a nitrogen-modified atmosphere and the indicated temperature not only most accurately maintained the coat color, but also provided the best glucose release results. The storage period and the cooking procedure reduced the free phenolic and proanthocyanidin content of the cowpeas, regardless of the applied storage conditions. Increases in the extractability of bound phenolics were observed, regardless of the storage conditions. Practical applications Results of the present study contribute to the understanding of the effects of the storage conditions on the cooking and nutritional quality of cowpeas and may help the cowpea production chain to adopt proper technologies in order to guarantee a constant supply of high-quality cowpeas to consumers from the developed and developing countries. The color, physicochemical properties, and starch digestibility were considered in the determination of the quality of stored cowpeas.

Translation errors of noodles product cooking instructions from Indonesian into English

This paper discussed the translation errors in various top brands of instant noodles in Indonesia, ranging from the products produced by the local industries to the one imported from overseas. In this research, the researchers used a descriptive qualitative research method. The sources of the data for the objects of the research were ten cooking instructions or procedures of various brands of instant noodles in Indonesia, translated from Indonesian into English. The data were collected by documentation techniques. The types of data were words, phrases and sentences. The data were classified and tabulated based on the error types, following the standard of ATA’s Framework for Standard Error Making Classification. The result of the analysis showed that there were 40 translation errors, found in 10 of 23 error categories with Omission as the most frequent error produced. The three most prominent error categories found in the instant noodles’ cooking instructions are Omission, Mistranslation, Syntax and Cohesion. Omission turns to be the highest category of translation errors which appeared 13 times out of 40 errors or 32.5 % of errors found in the analysis, followed by Mistranslation with 15% and Syntax and Cohesion that shares the same percentage of findings by reaching 12.5%. The researchers also found that out of 10 instant noodle brands, instant noodle brand D has the most translation errors with 9 error out of 40 errors in total, followed by brand J with 8 errors. The implication of the study is that the findings are hoped to be useful for the industry in terms of usage of English in labeling and branding the products, to avoid miscommunication and misinterpretation.

Comparative study of the phytochemical and mineral composition of fresh and cooked broccolini

Broccolini is originated from crossing the regular broccoli with Chinese kale. Consequently, it has similar properties to these vegetables, but other very particular characteristics. Its consumption has increased in the last few years and, consequently, there have been some studies related to its quality parameters and the influence of different cooking methods. Nevertheless, changes on its phenolic composition and mineral content originated by its cooking have not been investigated in-depth so far. Here we report the phytochemical profile of broccolini before and after boiling, steaming, and griddling cooking treatments. The mineral content and phytochemicals were assessed by inductively coupled plasma-mass spectrometry (ICP-MS) and high performance liquid chromatography-mass spectrometry (HPLC-MS), respectively. The main phenolics (mainly hydroxycinnamic acid derivatives from caffeic, coumaric, ferulic and sinapic acids) were quantified. Three oxylipins, three flavonoid glycosides and the glucosinolate glucobrassicin were also identified. ABTS and DPPH assays were also used as screening methods to assess the antioxidant potential of broccolini. A significant loss of the phenolic compounds and a reduction of the antioxidant activity were observed after the three cooking methods. Clear disadvantages were detected when broccolini was boiled, namely high losses of phenolic acids and derivatives (70%). Steaming and griddling also led to a significant loss of phenolics (50%) from fresh broccolini. The mineral content of this vegetable after domestic cooking procedures is also reported for the first time, calculating the contribution of broccolini consumption to official daily recommendations.

Video-based recipe retrieval

Recipe retrieval has received great attention in the research community, which focuses on retrieving a textual recipe given a text or an image as the query. However, cooking is an interesting activity, and many useful elements are hidden in the dynamic videos, which might be omitted in the statistic texts and images. On the other hand, although a number of video-based retrieval methods have been investigated in the past, existing technologies mainly focus on general applications and seldom take the domain-specific feature into account. To bridge the above gap, we investigate a new problem of video-based recipe retrieval, which refers to retrieving a cooking video from a list of video candidates given a textual recipe as the query, or the reverse side.In this work, we first propose a hierarchical attention network to learn the representations of textual recipe and its cooking procedures. Moreover, we employ reinforcement learning to dynamically locate a video moment given a cooking procedure as the query. Thereafter, the representations of video moments and cooking procedures are projected into a common space and optimized with a pairwise ranking loss, which is able to distinguish the matched and unmatched video moment-cooking procedure pairs. Therefore, the retrieval process between cooking videos and textual recipes is performed as the assembling matching results of video moments and cooking procedures. By experimenting on a self-collected dataset, we demonstrate the effectiveness and rationality of our proposed solution on the scope of both overall performance comparison and micro-level analyses.

Reducing Veterinary Drug Residues in Animal Products: A Review.

A survey we conducted suggests that the ingestion of veterinary drug residues in edible animal parts constitutes a potential health hazard for its consumers, including, specifically, the possibility of developing multidrug resistance, carcinogenicity, and disruption of intestinal normal microflora. The survey results indicated that antibiotics, parasitic drugs, anticoccidial, or nonsteroidal anti-inflammatory drugs (NSAIDs) are broadly used, and this use in livestock is associated with the appearance of residues in various animal products such as milk, meat, and eggs. We observed that different cooking procedures, heating temperatures, storage times, fermentation, and pH have the potential to decrease drug residues in animal products. Several studies have reported the use of thermal treatments and sterilization to decrease the quantity of antibiotics such as tetracycline, oxytetracycline, macrolides, and sulfonamides, in animal products. Fermentation treatments also decreased levels of penicillin and pesticides such as dimethoate, malathion, Dichlorodiphenyldichloroethylene, and lindane. pH, known to influence decreases in cloxacillin and oxacillin levels, reportedly enhanced the dissolution of antimicrobial drug residues. Pressure cooking also reduced aldrin, dieldrin, and endosulfan in animal products. Therefore, this review provides updated information on the control of drug residues in animal products, which is of significance to veterinarians, livestock producers, and consumer health.

Food safety risk assessment of metal pollution in crayfish from two historical mining areas: Accounting for bioavailability and cooking extractability

Here we characterize the bioaccumulation of mercury (Hg) and lead (Pb) in red swamp crayfish (Procambarus clarkii) from two river courses in Central Spain that are impacted by historical Hg and Pb mining activities, respectively. We estimate the absolute oral bioavailability of metals in crayfish tissues by means of in vitro bioaccessibility simulations, and assess whether their consumption may imply a health risk for humans by estimating target hazard quotients and safe consumption rates. We also study the effect of cooking crayfish on the mobilization of the metal body burden in the context of the traditional Spanish cuisine. The results showed that crayfish from the mining districts accumulated a high level of Hg and Pb pollution in both the tail muscle and the carcass. The in vitro bioaccessibility of Hg and Pb in the edible part was 27.86 ± 4.05 and 33.73 ± 5.91%, respectively. Absolute bioavailability was estimated to be 38.31 for Hg, and 20.21 (adults) and 67.35% (children) for Pb. Risk indices indicated that, even after adjusting for bioavailability, it is not safe to consume crayfish from the mining-impacted rivers because of their high levels of Hg and Pb. Using the carcass as a condiment for flavouring should also be avoided. The cooking procedure extracted relatively small amounts of the total Hg (8.92 ± 2.13%) and Pb (1.68 ± 0.29%) body burden. Further research that will support human and ecological risk assessment, along with the implementation of advisory measures for the local population as regards crayfish consumption, are recommended.

How Toxic is Milkweed when Harvested and Cooked according to Myaamia Tradition?

Asclepias syriaca L. (common milkweed) is known to contain sufficient amounts of cardiac glycosides, which are known to be toxic to humans. Nonetheless, it is traditionally used for food by Native Americans, including the Myaamia people of Indiana and Oklahoma. In order to test the hypothesis that traditional horticultural and culinary practices prevent the Myaamia from ingesting toxic levels of cardiac glycosides, we have determined the level of glycosides (digitoxin equivalent) in A. syriaca 1) in various parts of the plant, 2) at various heights for pre-reproductive plants, and 3) before and after cooking according to traditional Myaamia procedures. Plants were grown, harvested, dried, ground, and extracted twice with ethanol. The amount of digitoxin-equivalent glycoside in plant extract was determined spectrophotometrically using 2,2’,4,4’-tetranitrodiphenyl, a selective derivatizing agent. We find that all parts of the plant contain significant levels of cardiac glycosides at all stages of growth. Plants harvested as young shoots for food, the common practice of the Myaamia, contain slightly lower levels of cardiac glycosides when compared to the leaves and stems of older, taller plants. Moreover, the toxicity is significantly reduced by the traditional Myaamia cooking procedure—a repeated boiling with several changes of water. Therefore, it appears as though the risk of glycoside poisoning from traditional Myaamia use of milkweed for food is moderated by their harvesting practice and traditional cooking procedure.

Monitoring of Chlorogenic Acid and Antioxidant Capacity of Solanum melongena L. (Eggplant) under Different Heat and Storage Treatments.

Solanum melongena L., also known as eggplant, is a widely consumed vegetable and it is well-known for its beneficial antioxidant properties, due to phenolic compounds. In this work, the influence of different cooking procedures on the content of chlorogenic acid was evaluated on eggplant samples of different geographic origin by high-performance liquid chromatography (HPLC). An easy and quick extraction procedure with 50% methanol as the extraction solvent was optimized for the first time by means of a design-of-experiment and applied to heat treated samples of eggplant. The antioxidant capacity of eggplant extracts was also evaluated by using the ABTS assay and it was correlated with the data obtained by the HPLC method. The content of chlorogenic acid was different in each heat-treated eggplant sample and it depended on the temperature applied during the cooking procedure. In particular, an increase of chlorogenic acid content with rising temperature was observed. Conversely, a very high temperature (250 °C) caused a decrease of chlorogenic acid amount. The influence of storage on the content of chlorogenic acid was also monitored. While the level of chlorogenic acid in fresh samples decreased during four weeks of storage, an increase in its content in heat treated eggplant was observed within the same period. Multivariate data analysis was used to classify eggplant samples into different groups, according to the country of origin and heat treatment procedure. This study provides new insights to preserve the antioxidant properties of eggplant phenolics during different thermal and storage treatments in order to highlight their health promoting effects.