Antioxidant ability of potato (Solanum tuberosum) peel extracts to inhibit soybean oil oxidation

Lipophilic antioxidants in edible oils: Mechanisms, applications and interactions

Essential fatty acids (EFAs) in edible oils are crucial for human nutrition. However, their high unsaturation renders edible oils susceptible to oxidation during storage and processing. The addition of lipophilic antioxidants is an effective strategy to inhibit oxidation and safeguard the nutritional integrity of edible oils. This review focused on the diverse mechanisms and applications of lipophilic antioxidants to inhibit oxidation of edible oils. A range of both synthetic and natural lipophilic antioxidants, including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), propyl gallate (PG), tocopherols, tocopherols, carotenoids, flavonoids, ascorbyl palmitate, and lipophilic phenolic compounds were discussed. Moreover, lipophilic antioxidant extracts, as the mixture of natural lipophilic antioxidants, can significantly inhibit oil oxidation. The interaction mechanisms of natural lipophilic antioxidants were reviewed. However, compared to synthetic lipophilic antioxidants, the mechanisms and interactions of natural lipophilic antioxidants need to be further studied. Additionally, their stability and solubility, the extraction and purification costs, and the impact on the sensory must be considered when applying natural lipophilic antioxidants to edible oils. This review serves as a timely reference for application of natural lipophilic antioxidants in edible oils, contributing to the development of healthier and more sustainable options.

Valorization of saffron (Crocus sativus L.) stigma as a potential natural antioxidant for soybean (Glycine max L.) oil stabilization

Synthetic antioxidants are known for their efficiency to improve vegetable oil oxidative stability. But owing to their harmful effects on human health, edible oil industry is seeking for safe and healthy natural antioxidants. The present work was setup with the aim of improving soybean oil (SO) oxidative stability by using saffron (Crocus sativus L.) stigmas collected in Morocco. Saffron stigmas were used as a natural antioxidant at various concentrations (0.2, 0.3, and 0.6%) in soybean oil compared to tocobiol (0.3%) as a synthetic antioxidant (the positive control). Performances of such natural and synthetic antioxidants were evaluated by measuring oil basic quality indices under accelerated storage at 60 °C for 12 weeks. Such indices consisted of free fatty acids (FFA), peroxide value (PV), anisidine value (p-AV), total oxidation value (TOTOX), UV extinction coefficients (K232 and K270), fatty acids composition (FA), and iodine value (IV). The obtained data show that there were significant (p < 0.05) increases in FFA, PV, p-AV, K232, K270, and TOTOX but no much variations were observed for FA and IV especially in saffron stigmas fortified oils across storage times. However, in the case of oils fortified with saffron stigmas at different doses, such an increase was of a lesser magnitude (for FFA, PV, p-AV, K270, and TOTOX) as compared to tocobiol. These outcomes were confirmed by principal component analysis with strong positive correlations (p < 0.001) among FFA, PV, p-AV, K232, K270, and TOTOX. The most important, for which determination coefficient R2 > 0.9, were modeled through simple regressions. In conclusion, saffron stigmas with the different doses performed better than the positive control (tocobiol) regardless of the storage time. It could be concluded that saffron stigmas are a promising natural antioxidant, alternative to synthetic antioxidants, to enhance the oxidative stability of edible oils.

Metabolomics Reveals the Response Mechanisms of Potato Tubers to Light Exposure and Wounding during Storage and Cooking Processes

Potato is susceptible to light exposure and wounding during harvesting and transportation. However, the metabolite profile changes in these potato tubers are unclear. The potato cultivars in this study included Hezuo88 (HZ88), Shida6 (SD6), and Jianchuanhong (JCH); the effects of light exposure (L), wounding (W), and the cooking process on potato metabolites were determined. In total, 973 metabolites were identified, with differential metabolites (mainly alkaloids, flavonoids, and phenolic acids) accumulated on days 0 and 2 (0 d and 2 d) in the 0dHZ88 vs. 0dJCH (189), 0dHZ88 vs. 0dSD6 (147), 0dSD6 vs. 0dJCH (91), 0dJCH vs. 2dIJCH (151), 0dJCH vs. 2dWDJCH (250), 0dJCH vs. 2dWLJCH (255), 2dIJCH vs. 2dWDJCH (234), and 2dIJCH vs. 2dWLJCH (292) groups. The flavonoid content in the light exposure group was higher than that in the dark group. The alkaloid content in the wounded group was higher than that in the uninjured potato tuber group, but the lipid content in the wounded group was lower. Importantly, only 5.54% of the metabolites changed after potato tuber steaming. These results provide valuable information for the breeding and consumption of potato tubers.

Composition and Antioxidant Ability of Extract from Different Flaxseed Cakes and Its Application in Flaxseed Oil

In this research, extracts from five flaxseed cakes (hot-pressed cake (HPC), cold-pressed cake (CPC), n-hexane extracted cake (HEC), supercritical CO₂ extracted cake (SCEC) and subcritical n-butane extracted cake (SBEC)) were analyzed for the contents of total phenolic, total flavonoid and antioxidant ability. At the same time, the antioxidant capacity of HPC extract and synthetic butylated hydroxyanisole (BHA) in the oxidative evolution of flaxseed oil was compared by accelerated storage experiment (8 days at 65°C). The results showed that compared with other flaxseed cake extract, the extract of HPC contained the highest content of total phenolic (78.01 mg GAE/g extract) and total flavonoid (2.73 mg RE/g extract), and showed the strongest antioxidant ability on DPPH, ABTS FRAP and total reducing power assay. We also found that different concentrations (800, 1000, 2000 ppm) of flaxseed cake extract could significantly slow down the oxidation of flaxseed oil during storage at 65°C, and the antioxidant effect strengthened with the increase of extract dosage. The antioxidant effect of the 2000 ppm extract was higher than that of 200 ppm BHA. The results indicated that flaxseed cake extract could effectively inhibit the oxidation of flaxseed oil and was a good substitute for synthetic antioxidants in oil industry.

Optimization of Conventional Extraction Parameters for Recovering Phenolic Compounds from Potato (Solanum tuberosum L.) Peels and Their Application as an Antioxidant in Yogurt Formulation

The aim of this work was to optimize the conventional parameters for the extraction of phenolic compounds from potato (Solanum tuberosum L.) peels (PP). A central composite design (CCD) was used to establish the impacts of ethanol concentration (%), extraction time (min), and liquid/solid ratio (mL/g). The optimal experimental conditions that maximized extraction were ethanol at a concentration of 80% (v/v) for a time of 150 min with a ratio of 1 g/30 mL. Under optimal conditions, the total phenolic content (TPC) and the total flavonoid content (TFC) were 204.41 ± 8.64 mg GAE/100 g DW and 21.47 ± 0.76 mg QE/100 g DW, respectively. The PP extract had a potent antioxidant capacity tested by phosphomolybdate and DPPH assays with IC₅₀ of 10.65 ± 0.21 and 179.75 ± 3.18 µg/mL, respectively. Furthermore, by fortifying yogurt with PP as a natural ingredient, an improvement ofits physical, nutritional, antioxidant, and sensorial qualities was attempted in this study. The yogurts formulated with PP revealed significantly higher (p ≤ 0.05) TPC, TFC, and antioxidant capacity in comparison with the control sample. In addition, the sensory evaluation showed that the yogurts enriched with PP were preferred over the control yogurt. The results indicate that PP can be considered an interesting byproduct since it can improve the nutritional, bioactive, and sensorial profile of yogurt, highlighting that PP, due to its high phenol content, can substantially improve the antioxidant effect of the new formulated yogurt.

The Antioxidant Effect of Colombian Berry (Vaccinium meridionale Sw.) Extracts to Prevent Lipid Oxidation during Pork Patties Shelf-Life

A scarce amount of knowledge about the use of Colombian berry (CB) in meat products is available in the literature. This work studies the impact of the addition of CB extracts (CBE) on pork patties at three different concentrations in the range 250–750 mg/kg. CBE were characterized in terms of their polyphenolic profile and antioxidant activity [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, half maximal inhibitory antioxidant concentration (IC₅₀), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP) and oxygen radical absorbance capacity (ORAC) tests)]. After pork patties elaboration, instrumental and sensorial colour, as well as lipid oxidation measured as thiobarbituric acid reactive substances assay (TBARS) values, were evaluated for 10 days of refrigerated storage in a modified atmosphere (80% O₂–20% CO₂). The total anthocyanin composition represented 35% of the polyphenolic substances of the CBE, highlighting high contents in cyanidin derivatives. Additionally, other flavonoids (quercetin and kaempferol compounds) and phenolics acids, substances positively related to antioxidant activity, were identified and quantified. In addition, the incorporation of CBE resulted in improvements in colour and lipid stability of pork patties, especially for the highest concentration used. Our findings demonstrated that CBE could be added to pork patties without impairing their sensorial profile. Overall, our results indicate that the use of CBE as a source of natural antioxidant, natural colourant, or even as a functional ingredient could be promising, but more studies are necessary to confirm it.

Modelling the Effects of Roselle Extract, Potato Peel Flour, and Beef Fat on the Sensory Properties and Heterocyclic Amines Formation of Beef Patties Studied by Using Response Surface Methodology

Heterocyclic amines (HCAs) are compounds with carcinogenic potential formed during high-temperature processing of meat and meat products. Vegetables or their extracts with high antioxidant capacity can be incorporated into the meat matrix to reduce their formation, but it is necessary to find the optimal levels to achieve maximum inhibition without affecting the sensory properties. The objective of this study was to evaluate the effects of roselle extract (RE, 0-1%), potato peel flour (PP, 0-2%), and beef fat (BF, 0-15%) on the sensory properties and formation of HCAs in beef patties using response surface methodology. IQx, IQ, MeIQx, MeIQ, 4,8-DiMeIQx, and PhIP were identified and quantified by HPLC. Regression models were developed to predict sensory properties and HCAs' formation. All models were significant (p < 0.05) and showed a R2 > 0.70. Roselle extract and beef fat had a negative linear effect on the formation of the total HCAs, while PP had a positive linear effect. The optimal formula that minimizes the formation of HCAs included 0.63% RE, 0.99% PP, and 11.96% BF. RE and PP are foods that can be used as ingredients in low-fat beef patties to minimize the formation of HCAs without affecting their sensory properties.

Improving the quality of vegetable oils treated with phytochemicals: a comparative study

In this study, sunflower, corn, peanut and hazelnut oils were investigated according to their oxidative stability and antioxidant activity parameters. The related vegetable oils were treated with gallic acid, rutin and carotenoid. Olive leaf extract having a large variety of phytochemical was also valorized. After the leaf samples were extracted through a homogenizer, they were added into the vegetable oils, respectively. Moreover, synthetic antioxidants were also dissolved into the oils for control reasons. Stability of the vegetable oils against the oxidation was evaluated via Rancimat by measuring induction time. The quality parameters of treated and untreated oil samples were compared depending on phenolic and carotenoid contents, antioxidant activity and induction time.

Pomegranate Peel as Suitable Source of High-Added Value Bioactives: Tailored Functionalized Meat Products

In the last few years, the consumer's concern with the relationship between health and diet has led to the search of foods with functional properties beyond the nutritional. In this framework, the consumption of pomegranate has increased due to their sensorial attributes and remarkable amounts of bioactive compounds, which generate, at the same time, huge amounts of by-products. A search in the Scopus database for the last 10 years has revealed the rising interest in pomegranate peel (PP), the main residue from this fruit. The meat industry is a food sector that has had to search for new alternatives to substitute the use of synthetic preservatives by new natural additives, to extend the self-life and keep the quality attributes of their processed products. This review sets out the main bioactivities of PP extracts, and their incorporation in meat products is elaborated. PP is a good source of bioactive compounds, including phenolic acids, flavonoids and hydrolyzable tannins, which have beneficial health effects. It can be concluded that the reformulation of meat products with PP extracts is a suitable strategy for enhancing their technological characteristics, in addition to conferring functional properties that make them healthier and potentially more acceptable for the consumer.

Consumer Acceptance and Quality Parameters of the Commercial Olive Oils Manufactured with Cultivars Grown in Galicia (NW Spain)

Mansa and Brava are olive autochthonous cultivars from Galicia, a new olive-growing zone from NW Spanish, from which high-quality extra virgin olive oils (EVOOs) are obtained. The oils obtained as by co-crushing Mansa and Brava olives in different proportions as by blending with others olives cultivars have different composition that influence in their sensory quality. The consumer acceptance of commercial oils elaborated with Local Galician cultivars was evaluated and a quality-mapping of olive oils was created. It was found that the both Local oils had good physical-chemical quality parameters. From sensory analysis viewpoint, Local-MB oils presented the highest intensity values for color, odor, taste, and flavor, and the consumers had a higher acceptance and preference by Picual, Local-MBPA (60% Mansa and Brava, 25% Picual, and 15% Arbequina and Local-MB (60% Mansa and 40% Brava) oils. A quality-mapping of olive oils indicate that attributes better scored from the consumer are high intensity for color, odor, taste and flavor, and pungent and floral series, and bitter is rejected by them.

Potato Peels as a Source of Novel Green Extracts Suitable as Antioxidant Additives for Fresh-Cut Fruits

Potato is a source of different bioactive compounds, and the potato transformation industry produces conspicuous quantities of potato peels as waste. In this context, the objective of this research was twofold: (i) the evaluation of the recovery of bioactive compounds from organic potato byproducts through an innovative multistep green extraction process; (ii) to evaluate the preservation during storage of the main quality-physicochemical parameters of minimally processed apples treated with two different natural extracts obtained. The potato extracts were obtained by solid CO2 cryomaceration followed by solid/liquid extraction based on water or 10% ethanol/water solutions. The efficacy of potato extracts, with or without 1% of citric acid, was tested in comparison with traditional preserving compounds in minimally processed apple preparation. All the extracts were characterized by a high antioxidant power and were rich in phenol compounds, showing a good activity in keeping the qualitative parameters of fresh-cut apple. A significant anti-browning effect as well as a slowing down of the softening of fruits during storage were observed. The obtained results suggest the suitability of the potato extracts as antioxidant additives for fresh-cut fruits, thus avoiding the use of unsafe chemicals.

Guarana seed extracts as a useful strategy to extend the shelf life of pork patties: UHPLC-ESI/QTOF phenolic profile and impact on microbial inactivation, lipid and protein oxidation and antioxidant capacity

The antioxidant and antimicrobial effects of guarana seed extracts (GSE) added to pork patties were evaluated for 18 days storage at 2 ± 1 °C. Five treatments were prepared: i) without natural antioxidant [control (negative control)], ii) with BHT at 200 mg/kg (positive control), and iii) with three different concentrations: 250  mg/kg (guarana seed low dose-GSL), 500  mg/kg (guarana seed medium dose-GSM) and 1000  mg/kg (guarana seed high dose-GSH) of guarana extracts, respectively. The pH, instrumental colour (CIE L*, a*, b*), total viable counts (TVC), Pseudomonas spp. counts and lactic acid bacteria (LAB) counts, 2-thiobarbituric acid reactive substances (TBARS) and carbonyl content were determined after 0, 7, 11, 15 and 18 days of storage period. The in vitro antioxidant activity together with the phenolic profile of GSE was also studied. Microbial analysis showed that GSE had no antimicrobial activity on pork patties. The untargeted UHPLC-ESI-QTOF approach confirmed the wide phenolic composition of GSE able to explain the antioxidant power (28.2 g/kg of phenolic equivalents). Low doses (GSL) of GSE were able to preserve the values of colour parameters, obtaining higher L*, a* and b* values during storage, which is reflected in the lowest colour differences during storage (ΔE*_0-18 = 4.56). TBARS and carbonyls values in GSE added samples were lower than control and BHT ones. GSL and GSM provided better results than the synthetic antioxidant (0.08 and 0.07 vs 0.18 mg MDA/kg; 2.47 and 3.13 vs 3.23 nmol/mg, for GSL and GSM vs BHT, respectively). These findings show that GSE are very effective against colour deterioration, lipid and protein oxidation in pork patties and possessing the potential to be used as natural antioxidants.

Practical use of natural antioxidants in meat products in the U.S.: A review

Historically, meat and poultry processors in the U.S. have relied on the use of synthetic antioxidants like butylated hydroxyanisole, butylated hydroxytoluene, tert-butylhydroquinone, and propyl gallate, as well as tocopherols to prevent lipid and protein oxidation. There is a trend towards utilizing natural antioxidants as replacements for synthetic ones. Some processors are already using multi-functional ingredients, such as rosemary and oregano, approved for use as spices and natural flavors to curb oxidation. Yet, there are still other ingredients that have not been applied in this fashion. Spices and natural flavors can often be incorporated in products that have defined statements of identity or composition. Further, these ingredients allow the processor to transition to a clean label without compromising the shelf life and quality of the products. Spices and natural flavors may have higher minimum effective concentrations than their synthetic counterparts, but they will offer increased consumer acceptability, decreased potential health risks, and can often achieve the same degree of oxidation prevention.

Application of hull, bur and leaf chestnut extracts on the shelf-life of beef patties stored under MAP: Evaluation of their impact on physicochemical properties, lipid oxidation, antioxidant, and antimicrobial potential

The impact of chestnut extracts (Castanea sativa) from leaf, bur and hull at different concentrations on the shelf-life of beef patties during 18 days of refrigerated storage at (2 ± 1 °C) was studied and compared to control and synthetic antioxidant (BHT) samples. Total phenolics and in vitro antioxidant capacity of extracts were evaluated by using DPPH, FRAP, reducing power and oil accelerated oxidation test (peroxide value, conjugated dienes, p-anisidine and fatty acid profile). The microbial spoilage, colour parameters, lipid oxidation and sensorial properties were used to assess antioxidant activity in beef patties. The highest total phenolic content was found in bur extracts (43.68 ± 2.05 g/100 g lyophilized extract). In addition, bur extracts showed the strongest antioxidant activity in all in vitro assays. None of the evaluated extracts showed antimicrobial activity. The addition of hull extracts at 500 and 1000 ppm resulted in the highest (P < .05) metmyoglobin reduction in the surface of beef patties compared to control and the others batches after 15 days of storage. However, leaf extract at 1000 ppm was the most effective in inhibiting lipid oxidation. Overall, for all extracts evaluated, the increase in the concentration of chestnuts extracts improved the desired effect, hence our findings suggest the possibility of using chestnuts extracts (preferable a mixture from the different parts of the chestnut byproducts) rather than synthetic antioxidants. Finally, sensorial analysis did not show any detrimental effect from a sensory point of view, after the addition of chestnuts extracts, thus indicating a potential to develop chestnut extracts as food ingredients.

Proximate composition, phenolic content and in vitro antioxidant activity of aqueous extracts of the seaweeds Ascophyllum nodosum, Bifurcaria bifurcata and Fucus vesiculosus. Effect of addition of the extracts on the oxidative stability of canola oil under accelerated storage conditions

Extracts from three macroalgae species (Ascophyllum nodosum (ANE), Bifurcaria bifurcata (BBE) and Fucus vesiculosus (FVE)) were tested for proximate composition (total solid, protein and total carbohydrate contents), total phenols content (TPC), and for their antioxidant activities in vitro in comparison to that of BHT compound by using four different assays (ABTS radical cation decolouration, DPPH free radical scavenging activity, ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC)). The inclusion of the extracts as oil stabilizers in canola oil in substitution of the synthetic antioxidant (BHT) was also evaluated by assessing lipid oxidation parameters (peroxide value (PV), p-anisidine value (AV), TBARS value, conjugated dienes (CD) and TOTOX index) under accelerated storage conditions (16days, 60°C). There was an inverse relationship between total solid content and total polyphenols content in the seaweed extracts. FVE showed an intermediate TPC (1.15g PGE/100g extract), but it presented the highest in vitro antioxidant activity when measured using the ABTS, DPPH and FRAP tests. BBE, that displayed the highest TPC (1.99g PGE/100g extract), only showed the highest in vitro antioxidant activity when measured using the ORAC test. ANE showed the lowest TPC and the lowest antioxidant activity in all the tests performed. The seaweed extracts added in a 500ppm concentration significantly reduced the oxidation during canola oil storage at 60°C, being this antioxidant effect significantly higher than that of BHT added at 50ppm. Results indicate that seaweed extracts can effectively inhibit the oxidation of canola oil and they can be a healthier alternative to the synthetic antioxidants in the oil industry.

Effect of olive leaf extract rich in oleuropein on the quality of virgin olive oil

Effect of olive leaf extract rich in oleuropein on the quality of virgin olive oil was investigated. After extracting the dried and ground olive leaves with the assistance of homogenizer, the dried extract was partially dissolved into the oil to increase the oxidative stability of the oil. A face central composite design through response surface methodology was used to investigate the effects of enrichment conditions (extract content, time and mixing speed) on the responses, total phenolic content and oleuropein concentration of the enriched olive oil. Furthermore, antioxidant activity of the oil was determined by 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt method. Additionally, oxidative stability of the enriched oil was assessed by the Rancimat method. Total carotenoid content, peroxide value, α-tocopherol and chlorophyll were also measured, respectively. Addition of 0.15% natural antioxidant increased the stability of the oil (≈46%). The antioxidant capacity of the enriched oil was almost 2.5 times higher than that of the untreated oil. Furthermore, olive leaf extract improved the quality of the virgin olive oil with respect to tocopherol, carotenoid and chlorophyll contents and peroxide value, respectively. The leaf sampling was also performed both in the autumn and summer to evaluate the possible seasonal effects on phenolic profile in order to be careful for selecting the proper harvesting time to apply the extract into the oil.