Identification of C9-C11 unsaturated aldehydes as prediction markers of growth and feed intake for non-ruminant animals fed oxidized soybean oil

Counteracting Roles of Lipidic Aldehydes and Phenolic Antioxidants on Soy Protein Oxidation Defined by a Chemometric Survey of Solvent and Mechanically Extracted Soybean Meals

Soybean meal (SBM) is a premier source of protein for feeding food-producing animals. However, its nutritional value can be compromised by protein oxidation. In this study, a total of 54 sources of solvent extracted SBM (SSBM) and eight sources of mechanically extracted SBM (MSBM), collected from different commercial producers and geographic locations in the United States during the years 2020 and 2021, were examined by chemometric analysis to determine the extent of protein oxidation and its correlation with soybean oil extraction methods and non-protein components. The results showed substantial differences between SSBM and MSBM in the proximate analysis composition, protein carbonyl content, lipidic aldehydes, and antioxidants, as well as subtle differences between 2020 SSBM and 2021 SSBM samples in protein oxidation and moisture content. Correlation analysis further showed positive correlations between protein carbonyl content and multiple lipid parameters, including the ether extract, p-anisidine value, individual aldehydes, and total aldehydes. Among the antioxidants in SBM, negative correlations with protein carbonyl content were observed for total phenolic content and isoflavone glycoside concentrations, but not for Trolox equivalent antioxidant capacity (TEAC), α-tocopherol, and γ-tocopherol. Overall, soybean oil extraction methods, together with other factors such as enzyme treatment and environmental conditions, can significantly affect the proximate analysis composition, the protein and lipid oxidation status, and the antioxidant profile of SBM. Lipidic aldehydes and phenolic antioxidants play counteracting roles in the oxidation of soy protein. The range of protein carbonyl content measured in this study could serve as a reference to evaluate the protein quality of SBM from various sources used in animal feed.

Identification of Protective Amino Acid Metabolism Events in Nursery Pigs Fed Thermally Oxidized Corn Oil

Feeding thermally oxidized lipids to pigs has been shown to compromise growth and health, reduce energy digestibility, and disrupt lipid metabolism. However, the effects of feeding oxidized lipids on amino acid metabolism in pigs have not been well defined even though amino acids are indispensable for the subsistence of energy metabolism, protein synthesis, the antioxidant system, and many other functions essential for pig growth and health. In this study, oxidized corn oil (OCO)-elicited changes in amino acid homeostasis of nursery pigs were examined by metabolomics-based biochemical analysis. The results showed that serum and hepatic free amino acids and metabolites, including tryptophan, threonine, alanine, glutamate, and glutathione, as well as associated metabolic pathways, were selectively altered by feeding OCO, and more importantly, many of these metabolic events possess protective functions. Specifically, OCO activated tryptophan-nicotinamide adenosine dinucleotide (NAD⁺) synthesis by the transcriptional upregulation of the kynurenine pathway in tryptophan catabolism and promoted adenine nucleotide biosynthesis. Feeding OCO induced oxidative stress, causing decreases in glutathione (GSH)/oxidized glutathione (GSSG) ratio, carnosine, and ascorbic acid in the liver but simultaneously promoted antioxidant responses as shown by the increases in hepatic GSH and GSSG as well as the transcriptional upregulation of GSH metabolism-related enzymes. Moreover, OCO reduced the catabolism of threonine to α-ketobutyrate in the liver by inhibiting the threonine dehydratase (TDH) route. Overall, these protective metabolic events indicate that below a certain threshold of OCO consumption, nursery pigs are capable of overcoming the oxidative stress and metabolic challenges posed by the consumption of oxidized lipids by adjusting antioxidant, nutrient, and energy metabolism, partially through the transcriptional regulation of amino acid metabolism.

Effect of Aliphatic Aldehydes on Flavor Formation in Glutathione-Ribose Maillard Reactions

The Maillard reaction (MR) is affected by lipid oxidation, the intermediate products of which are key to understanding this process. Herein, nine aliphatic aldehyde−glutathione−ribose models were designed to explore the influence of lipid oxidation products with different structures on the MR. The browning degree, fluorescence degree, and antioxidant activity of the MR products were determined, and the generated volatile organic compounds (VOCs) and nonvolatile compounds were analyzed by gas chromatography-mass spectrometry and ultra-performance liquid chromatography-mass spectrometry. A total of 108 VOCs and 596 nonvolatile compounds were detected. The principal component and hierarchical clustering analyses showed that saturated aldehydes mainly affected the VOCs generated by the MR, while unsaturated aldehydes significantly affected the nonvolatile compounds, which changed the taste attributes of the MR products. Compared with the control group, the addition of unsaturated aldehydes significantly increased the sourness score and decreased the umami score. In addition, the addition of unsaturated aldehydes decreased the antioxidant activity and changed the composition of nonvolatile compounds, especially aryl thioethers and medium chain fatty acids, with a strong correlation with umami and sourness in the electronic tongue analysis (p < 0.05). The addition of aliphatic aldehydes reduces the ultraviolet absorption of the intermediate products of MR browning, whereas saturated aldehydes reduce the browning degree of the MR products. Therefore, the flavor components of processed foods based on the MR can be effectively modified by the addition of lipid oxidation products.

Feeding thermally processed spray-dried egg whites, singly or in combination with 15-acetyldeoxynivalenol or peroxidized soybean oil on growth performance, digestibility, intestinal morphology, and oxidative status in nursery pigs

Two experiments (EXP) determined the susceptibility of spray-dried egg white (SDEW) to oxidation (heating at 100 °C for 72 h; thermally processed, TP) and whether feeding TP-SDEW, 15-acetyldeoxynivalenol (15-ADON), or peroxidized soybean oil (PSO), singularly or in combination, would affect pig performance, intestinal morphology, digestibility, and markers of oxidative stress in nursery pigs. In EXP 1, 32 pigs (7.14 kg body weight, BW) were placed individually into pens and fed diets containing either 12% SDEW, 6% TP-SDEW plus 6% SDEW, or 12% TP-SDEW. Performance was measured at the end of the 24-d feeding period with biological samples harvested following euthanasia. In EXP 2, 64 pigs (10.6 kg BW) were placed individually into pens and fed diets containing 7.5% soybean oil or PSO, 10% SDEW or TP-SDEW, and diets without or with 3 mg 15-ADON/kg diet in a 2 × 2 × 2 factorial arrangement. Performance was measured at the end of the 28-d feeding period with biological samples harvested following euthanasia. In EXP 1, dietary treatment did not affect pig performance, apparent ileal digestibility of amino acids (AAs), apparent total tract digestibility (ATTD) of gross energy (GE) or nitrogen (N), ileal crypt depth, or villi height:crypt depth ratio (P > 0.05). The effects of feeding TP-SDEW on protein damage in the plasma and liver (P < 0.05) were variable. In EXP 2, there were no three-way interactions and only one two-way interactions among dietary treatments on parameters evaluated. There was no effect of feeding TP-SDEW on ATTD of GE or N, intestinal morphology, or on oxidative markers in the plasma, liver, or ileum (P > 0.05). There was no effect of feeding diets containing added 15-ADON on ATTD of GE, ileal AA digestibility, intestinal morphology, oxidative markers in the plasma, liver, or ileum, or pig performance (P > 0.05). Feeding pigs diets containing PSO resulted in reduced ATTD of GE and N, plasma vitamin E concentration, and pig performance (P < 0.01) but did not affect intestinal morphology or oxidative markers in the liver or ileum (P > 0.05). In conclusion, it was difficult to induce protein oxidation in SDEW and when achieved there were limited effects on performance, digestibility, intestinal morphology, and oxidative status. Furthermore, singly adding 15-A-DON to a diet had no effect on the animal. At last, adding PSO reduces animal performance, but has limited effect on digestibility, intestinal morphology, and oxidative status in nursery pigs.

Changes in Chemical Composition of Flaxseed Oil during Thermal-Induced Oxidation and Resultant Effect on DSC Thermal Properties

To investigate the changes in chemical composition of flaxseed oil during thermal-induced oxidation and the resultant effect on thermal properties, samples with different oxidation levels were obtained by being heated at 180 °C for two hours and four hours. The oxidation degree was evaluated using peroxide value (PV), extinction coefficient at 232 nm and 268 nm (K232 and K268), and total polar compounds (TPC). Using chromatography, the fatty acid profile and triacylglycerol (TAG) profile were examined. Differential scanning calorimetry (DSC) was used to determine the crystallization and melting profiles. Thermal-induced oxidation of flaxseed oil led to a significant increase (p < 0.05) in PV, K232, K268, and TPC, but the relative content of linolenic acid (Ln) and LnLnLn reduced dramatically (p < 0.05). TPC derived from lipid degradation affected both crystallization and melting profiles. Statistical correlations showed that the onset temperature (Ton) of the crystallization curve was highly correlated with K232, TPC, and the relative content of LnLnLn (p < 0.05), whereas the offset temperature (Toff) of the melting curve was highly correlated with the relative content of most fatty acids (p < 0.05). This finding provides a new way of rapid evaluation of oxidation level and changes of chemical composition for flaxseed oils using DSC.

Effects of oxidized soybean oil on the performance of sows and jejunum health of suckling piglets

Oils provide a considerable amount of energy to the swine diet, but they are prone to lipid oxidation if not properly preserved. Consumption of oxidized oils can adversely affect the animal organism and even the offspring. This study investigated the impact of oxidized soybean oil in the diets of sows from 107 days gestation to 21 days of lactation on the performance of sows and jejunum health of suckling piglets. Sixteen sows were randomly allocated into two groups: one group (n = 8) was fed with the fresh soybean oil (FSO) diet, and another group (n = 8) was treated with the oxidized soybean oil (OSO) diet. Dietary oxidized soybean oil does not affect sow performance. Antioxidant enzyme activity in the milk was reduced significantly in the OSO group, such as the superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and catalase (CAT) activities (p < 0.05). On Day 21, oxidized soybean oil increased tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) levels in sow milk and the concentrations of TNF-α and IL-8 cytokines in plasma (p < 0.05). Suckling piglets from sows fed on OSO showed a trend towards increased IL-6 and TNF-α in plasma (p < 0.1). The mRNA expression of interleukin 1β (IL-1β) was augmented, whereas interleukin 10 (IL-10) was decreased, and zonula occludens-1 (ZO-1) had a tendency to be down-regulated in OSO treatment. This study revealed that the OSO of feed decreased the antioxidant capacity of milk, further contributing to the inflammatory response in the jejunum of suckling piglets.

Effect of Natural Antioxidants from Marigolds (Tagetes erecta L.) on the Oxidative Stability of Soybean Oil

In recent years, synthetic antioxidants that are widely used in foods have been shown to cause detrimental health effects, and there has been growing interest in antioxidants realised from natural plant extracts. In this study, we investigate the potential effects of natural antioxidant components extracted from the forage plant marigold on the oxidative stability of soybean oil. First, HPLC-Q-TOF-MS/MS was used with 1,1-diphenyl-2-picrylhydrazyl (DPPH) to screen and identify potential antioxidant components in marigold. Four main antioxidant components were identified, including quercetagetin-7-O-glucoside (1), quercetagetin (2), quercetin (3) and patuletin (4). Among them, quercetagetin (QG) exhibited the highest content and the strongest DPPH radical scavenging activity and effectively inhibited the production of oxidation products in soybean oil during accelerated oxidation, as indicated by reductions in the peroxide value (PV) and acid value (AV). Then, the fatty acids and volatile compounds of soybean oil were determined with gas chromatography–mass spectrometry (GC-MS) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). A total of 108 volatile components, including 16 alcohols, 23 aldehydes, 25 ketones, 4 acids, 15 esters, 18 hydrocarbons, and 7 other compounds, were identified. QG significantly reduced the content and number of aldehydes and ketones, whereas the formation of acids and hydrocarbons was completely prevented. In addition, the fatty acid analysis demonstrated that QG significantly inhibited oxidation of unsaturated fatty acids. Consequently, QG was identified as a potential, new natural antioxidant that is believed to be safe, effective and economical, and it may have potential for use in plant extracts feed additives.

Evidence-Based Challenges to the Continued Recommendation and Use of Peroxidatively-Susceptible Polyunsaturated Fatty Acid-Rich Culinary Oils for High-Temperature Frying Practises: Experimental Revelations Focused on Toxic Aldehydic Lipid Oxidation Products

In this manuscript, a series of research reports focused on dietary lipid oxidation products (LOPs), their toxicities and adverse health effects are critically reviewed in order to present a challenge to the mindset supporting, or strongly supporting, the notion that polyunsaturated fatty acid-laden frying oils are "safe" to use for high-temperature frying practises. The generation, physiological fates, and toxicities of less commonly known or documented LOPs, such as epoxy-fatty acids, are also considered. Primarily, an introduction to the sequential autocatalytic peroxidative degradation of unsaturated fatty acids (UFAs) occurring during frying episodes is described, as are the potential adverse health effects posed by the dietary consumption of aldehydic and other LOP toxins formed. In continuance, statistics on the dietary consumption of fried foods by humans are reviewed, with a special consideration of French fries. Subsequently, estimates of human dietary aldehyde intake are critically explored, which unfortunately are limited to acrolein and other lower homologues such as acetaldehyde and formaldehyde. However, a full update on estimates of quantities derived from fried food sources is provided here. Further items reviewed include the biochemical reactivities, metabolism and volatilities of aldehydic LOPs (the latter of which is of critical importance regarding the adverse health effects mediated by the inhalation of cooking/frying oil fumes); their toxicological actions, including sections focussed on governmental health authority tolerable daily intakes, delivery methods and routes employed for assessing such effects in animal model systems, along with problems encountered with the Cramer classification of such toxins. The mutagenicities, genotoxicities, and carcinogenic potential of aldehydes are then reviewed in some detail, and following this the physiological concentrations of aldehydes and their likely dietary sources are considered. Finally, conclusions from this study are drawn, with special reference to requirements for (1) the establishment of tolerable daily intake (TDI) values for a much wider range of aldehydic LOPs, and (2) the performance of future nutritional and epidemiological trials to explore associations between their dietary intake and the incidence and severity of non-communicable chronic diseases (NCDs).

Maternal Exposure to Oxidized Soybean Oil Impairs Placental Development by Modulating Nutrient Transporters in a Rat Model

INTRODUCTION

As an exogenous food contaminant, dietary oxidized lipid impairs growth and development, and triggers chronic diseases in humans or animals. This study explores the effects of soybean oil with different oxidative degree on the placental injury of gestational rats.

METHODS AND RESULTS

Thirty-two female adult rats are randomly assigned to four groups. The control group is fed the purified diet with fresh soybean oil (FSO), and the treatment groups are fed purified diets with lipid content replaced by oxidized soybean oil (OSO) at 200, 400, and 800 mEqO2 kg-1 from conception until delivery. On day 20 of gestation, OSO decreased placental and embryonic weights as the oxidative degree increased linearly and quadratically. The expression of Bax showed a linear increase, and Bcl-2 decreased as the oxidative degree increased. The expression of Fosl1 and Esx1 is linearly and quadratically decreased in OSO-treated groups than FSO group. OSO decreased the level of IL-10 but increased expression of IL-1β in placenta and plasma. OSO remarkably upregulates levels of Fatp1 and Glut1 and decreases expression of Snat2 and Glut3.

CONCLUSION

OSO aggravates placental injury by modulating nutrient transporters and apoptosis-related genes, impedes placental growth and development, and ultimately leads to the decrease of fetal weight.

Fingerprinting triacylglycerols and aldehydes as identity and thermal stability indicators of camellia oil through chemometric comparison with olive oil

Camellia oil is widely recognized as a high-quality culinary oil in East Asia for its organoleptic and health-promoting properties, but its chemical composition and thermal stability have not been comprehensively defined by comparisons with other oils. In this study, the triacylglycerols (TAGs) in camellia, olive, and six other edible oils were profiled by the liquid chromatography-mass spectrometry (LC-MS)-based chemometric analysis. Besides observing the similarity between camellia oil and olive oil, TAG profiling showed that OOO, POO, and OOG (O: oleic acid, P: palmitic acid, and G: gadoleic acid) can jointly serve as the identity markers of camellia oil. Thermal stability of virgin camellia oil (VCO) was further evaluated by extensive comparisons with virgin olive oil (VOO) in common lipid oxidation indicators, aldehyde production, and antioxidant and pro-oxidant contents. The results showed that p-anisidine value (AnV) was the sensitive lipid oxidation indicator, and C9-C11 aldehydes, including nonanal, 2-decenal, 2,4-decadienal, and 2-undecenal, were the most abundant aldehydes in heated VCO and VOO. Under the frying temperature, heated VCO had lower AnV and less aldehydes than heated VOO. Interestedly, the VCO had lower levels of pro-oxidant components, including α-linolenic acid, free fatty acids, and transition metals, as well as lower levels of antioxidants, including α-tocopherol and phenolics, than the VOO. Overall, great similarities and subtle differences in TAG and aldehyde profiles were observed between camellia and olive oils, and the thermal stability of camellia oil might be more dependent on the balance among its unsaturation level, pro-oxidant, and antioxidant components than a single factor.

Influence of feeding thermally peroxidized lipids on growth performance, lipid digestibility, and oxidative status in nursery pigs

Three experiments were conducted to evaluate oil source and peroxidation status (experiment 1) or peroxidized soybean oil (SO; experiments 2 and 3) on growth performance, oxidative stress, and digestibility of dietary ether extract (EE). In experiment 1, palm oil (PO), poultry fat (PF), canola oil (CO), and SO were evaluated, while in experiments 2 and 3, only SO was evaluated. Lipids were either an unheated control (CNT) or thermally processed at 90 °C for 72 hr, being added at 10%, 7.5%, or 3% of the diet in experiments 1, 2, and 3, respectively. In experiment 1, 288 pigs (body weight, BW, 6.1 kg) were fed 1 of 8 factorially arranged treatments with the first factor being lipid source (PO, PF, CO, and SO) and the second factor being peroxidation status (CNT or peroxidized). In experiment 2, 216 pigs (BW 5.8 kg) were fed 1 of 6 treatments consisting of 100%, 90%, 80%, 60%, 20%, and 0% CNT SO blended with 0%, 10%, 20%, 40%, 80%, and 100% peroxidized SO, respectively. In experiment 3, 72 pigs (BW 5.8 kg) were fed either CNT or peroxidized SO. Pigs were fed 21 d with feces collected on day 12 or 14 and pigs bled on day 12 blood collection. In experiment 1, an interaction between oil source and peroxidation status was observed for averaged daily gain (ADG) and average daily feed intake (ADFI; P = 0.10) which was due to no impact of feeding pigs peroxidized PO, PF, or SO on ADG or ADFI compared with feeding pigs CNT PO, PF, or SO, respectively; while pigs fed peroxidized CO resulted in reduced ADG and ADFI compared with pigs fed CNT CO. There was no interaction between oil source and peroxidation status, and no lipid source effect on gain to feed ratio (GF; P ≥ 0.84), but pigs fed the peroxidized lipids had a lower GF compared with pigs fed the CNT lipids (P = 0.09). In experiment 2, feeding pigs diets containing increasing levels of peroxidized SO resulted in reduced ADG (quadratic, P = 0.03), ADFI (linear, P = 0.01), and GF (quadratic, P = 0.01). In experiment 3, feeding peroxidized SO at 3% of the diet reduced ADG (P = 0.11) and ADFI (P = 0.13), with no observed change in GF (P = 0.62). Differences in plasma protein carbonyls, glutathione peroxidase, and vitamin E due to feeding peroxidized lipids were inconsistent across the 3 experiments. Digestibility of dietary EE was reduced in pigs fed peroxidized PO or SO (P = 0.01, experiment 1) and peroxidized SO in experiments 2 and 3 (P ≤ 0.02). In conclusion, the peroxidation status of dietary lipids consistently affects growth performance and EE digestibility but has a variable effect on measures of oxidative stress.