Ultrasound-assisted extraction of polyphenols from potato peels: profiling and kinetic modelling

peer-reviewedUltrasound‐assisted extraction (UAE) at 33 and 42 kHz has been investigated in the extraction of polyphenols from peels of two potato varieties, cream‐skinned Lady Claire (LC) and pink‐skinned Lady Rosetta (LR), commonly used in snack food production. Extraction efficacy between the UAE‐untreated (control) and the UAE‐treated extracts was assessed on the total phenolic content and antioxidant capacities (DPPH and FRAP). Application of UAE showed significantly higher recovery of phenolic compounds compared to solid–liquid extraction process alone. Lower ultrasonic frequency (33 kHz) was more effective in recovering polyphenols compared to 42 kHz ultrasonic treatment. The liquid chromatography‐tandem mass spectrometry revealed that chlorogenic acid and caffeic acid were the most prevalent phenolics in LR peels, whereas caffeic acid was dominant in LC peels. Peleg's equation showed a good correlation (R2 > 0.92) between the experimental values and the predicted values on the kinetics of UAE of phenolic compounds.The authors acknowledge financial support from the ‘NovTechIng’ project funded under the Food Institutional Research Measure (Project No. FIRM/11/F/050) by the Irish Department of Agriculture, Food and Marine

Antioxidant starch-based films with encapsulated eugenol. Application to sunflower oil preservation

[EN] Starch films containing eugenol, which was added to the film-forming dispersion in free form or encapsulated with different wall materials (whey protein or lecithin), were obtained by casting. The physical and the antioxidant properties of the films, the release kinetics of eugenol in different food simulants and their performance at preventing sunflower oil oxidation during storage were evaluated. Encapsulated eugenol modified the film microstructure, yielding less stretchable films with reduced water affinity, transparency and oxygen permeability as compared to films formulated with non-encapsulated eugenol. The addition of eugenol microcapsules containing oleic acid promoted the eugenol retention in the starch matrix during film formation and thus, these films exhibited the greatest antioxidant activity. Films developed with encapsulated eugenol powder containing lecithin and oleic acid were highly effective at preventing sunflower oil oxidation even throughout 53 days of storage at 30¿°C, maintaining low and almost constant values of peroxide index, conjugated dienes and trienes in comparison with the control samples.The authors acknowledge the financial support provided by the Spanish Ministerio de Educacion y Ciencia (Projects AGL2013-42989-R and AGL2016-76699-R). Author Emma Talon thanks the Universitat Politecnica de Valencia for a FPI Grant (99/2011). The authors also thank the services rendered by the Electron Microscopy Service of the UPV.Talón-Argente, E.; Vargas, M.; Chiralt, A.; González Martínez, MC. (2019). Antioxidant starch-based films with encapsulated eugenol. Application to sunflower oil preservation. LWT - Food Science and Technology. 113:1-10. https://doi.org/10.1016/j.lwt.2019.108290S11011

Using lignocellulosic fractions of coffee husk to improve properties of compatibilised starch-PLA blend films

[EN] The effectiveness of the incorporation of cellulosic reinforcing agents (cellulosic fibres: CF and cellulose nanocrystals: CNC) and antioxidant aqueous extract (AE) from coffee husk at improving the functional properties of compatibilised starch-PLA blend films was studied. Tensile and barrier properties, crystallization pattern and thermal behaviour were analysed in films containing 1 wt% of CF or CNC incorporated by two different methods or 5.8 wt% of antioxidant extract. The antioxidant properties of the films were also tested through their efficacy at preserving sunflower oil from oxidation. Of the cellulosic fractions, CNC directly blended with the starch phase were the most effective at reinforcing tensile properties of the material (148% and 45% increase in elastic modulus and tensile strength, respectively) and at reducing their water vapour and oxygen permeability (28% and 42% reduction, respectively). The AE did not improve the mechanical performance of the blend films, but conferred antioxidant capacity useful for food packaging applications.The authors thank the Ministerio de Economia y Competitividad (Spain) for the financial support provided through Project AGL2016-76699-R. The authors also wish to thank the Electron Microscopy Service of the UPV for their technical assistance.Collazo-Bigliardi, S.; Ortega-Toro, R.; Chiralt Boix, MA. (2019). Using lignocellulosic fractions of coffee husk to improve properties of compatibilised starch-PLA blend films. Food Packaging and Shelf Life. 22:1-10. https://doi.org/10.1016/j.fpsl.2019.100423S1102

Selections of donors depending on agronomic traits, seed yield components, and fatty acid profile for genetic improvement of Carthamus using stepwise multiple regression

Safflower (Carthamus tinctorius L.) is of potential interest to agriculture due to mainly variability of fatty acid composition of seeds oil. The purpose of this study was to evaluate various exotic genotypes of safflower for agronomic traits, components of seed yield and fatty acid content. For this purpose, plant height (cm), number of first, second and third branches/plant, seed yield/plant (g), thousand-seed weight (g), oil content (%), and composition of fatty acid were investigated. Stepwise multiple regression analysis was used to develop fitted equation to predicate seed yield/plant. Analysis of variance of agronomic traits showed high differences among genotypes. Although the safflower oil genotype K2 had the highest oil seed content (42.8%), K13 obtained the highest percentage of monounsaturated fatty acids (MUFA). Highest oleic type of safflower oil has been found in K13 and K26, which can be used as a source oil quality for plant breeding. Heritability as broad sense was high and ranged from 82% in number of secondary branches (NSB) and number of third branches (NTHB) to 99% in seed index (1000 seeds weight) and oil content. High genetic advance was found in plant height (PH), seed yield/plant (SYP) and 1000-seed weight, estimated at 43.41 cm, 21.34 g and 17.62 g, respectively. Stepwise multiple regression analysis indicated that, 99.2% of the total variation in seed yield/plant could be explained by variation in yield of secondary (YSB) branches, yield of first branches (YFB), yield of third branches (YTHB), plant height (PH) and spiny as dummy variable. 23.56% of the total variation in seed oil percent could be explained by variation in yield of first branches (YFB), seed index and spiny as dummy variable. The information detected here may be a useful tool for the selection of parents in safflower breeding program

Antioxidant ability of potato ( Solanum tuberosum

12 pages, 4 tables, 2 figuresPotato peels are an agro industrial waste of one of the major crops worldwide. However, the potential of potato peels as source of antioxidants in the food industry is not yet sufficiently known. In this work, the antioxidant effect of potato peel extract (PPE) on oxidative stability of soybean oil was evaluated. We found that the addition of low PPE concentrations to soybean oil at four different levels, expressed as chlorogenic acid concentrations (14.01, 20.37, and 31.94 ppm), affected lipid oxidation indices (peroxide, anisidine, and conjugated dienes values), fatty acid composition, and volatile compounds. Antioxidant effect increased with increasing dose extract. Inhibition percentages of hexanal production increased with the PPE concentration. In addition, low concentrations of PPE showed higher oxidation stability than control untreated samples. Overall, our study shows that low concentrations of PPE exhibited promising antioxidant activity to be applied over a wider range of products in the food industry.Isabel Rodríguez was funded by a postdoctoral contract from the Xunta de Galicia, Spain (Plan I2C, 2012).Peer reviewe

Potential of Low Cost Agro-Industrial Wastes as a Natural Antioxidant on Carcinogenic Acrylamide Formation in Potato Fried Chips

Acrylamide is classified as a toxic and a prospective carcinogen to humans, and it is formed during thermal process via Maillard reaction. In order to find innovative ways to diminish acrylamide formation in potato chips, several extracts of agricultural wastes including potato peels, olive leaves, lemon peels and pomegranate peels extracts were examined as a soaking pre-treatment before frying step. Total phenolic, total flavonoids, antioxidant activity, and the reduction in sugar and asparagine contents were additionally performed. Proximate composition of these wastes was found to be markedly higher in fat, carbohydrate and ash contents. Lemon peels and potato peels showed almost similar phenolic content (162 ± 0.93 and 157 ± 0.88 mg GAE /g, respectively) and exhibited strong ABTS and DPPH radical scavenging activities than the other wastes. The reduction percentage of reducing sugars and asparagine after soaking treatment ranged from 28.70 to 39.57% and from 22.71 to 29.55%, respectively. HPLC results showed higher level of acrylamide formation in control sample (104.94 mg/kg) and by using the wastes extracts of lemon peels, potato peels, olive leaves, and pomegranate peels succeeded to mitigate acrylamide level by 86.11%, 69.66%, 34.03%, and 11.08%, respectively. Thus, it can be concluded that the soaking of potato slices in the tested wastes extracts as antioxidant as pre-treatment before frying reduces the formation of acrylamide and in this way, the risks connected to acrylamide consumption could be regulated and managed