Grasas y Aceites

Controlled fermentation of heat-shocked, unsalted and inoculated Moroccan Picholine green olives

vie, 24 mar 2023 00:00:00 +0100

The present work reports the controlled fermentation of heat-shocked, unsalted and inoculated green olives. The effects of heat-shock (60, 70 and 80 °C three times for 5 min), inoculation with the oleuropeinolytic strain of L. plantarum FSO175 (L.p-FSO175) and the addition of Cell-Free Supernatant of C. pelliculosa L18 (CFS of C.p-L18) on the fermentation process of unsalted green olives were examined. The results showed a drastic reduction in the initial indigenous Enterobacteria, and an improvement in the acidification of heat-shocked olives at 70 and 80 °C, when compared to 60 °C. The inoculation with L.p-FSO175 and addition of CFS of C.p-L18 enhanced the fermentation and preservation of unsalted green olives, indicated by a significant decrease in pH, increase in free acidity and total disappearance of Enterobacteria. The heat-shock treatment at high temperature (80 °C), inoculation with L.p-FSO175 and addition of CFS of C.p-L18 led to the best reduction in bitterness, and favorable color changes (L, a, and b) in fermented olives. This sequential method led to more appreciated sensory characteristics (mainly bitterness and color) of fermented olives, lower spoilage incidence in olives, and reduced fermentation time to 50 days, and therefore may be suitable to control the fermentation of unsalted green olives of the Moroccan picholine variety.

Lipid profile, volatile compounds and oxidative stability during the storage of Moroccan Opuntia ficus-indica seed oil

jue, 16 mar 2023 00:00:00 +0100

The fatty acids, sterol, tocopherol and volatile compositions of Moroccan cold-pressed cactus (Opuntia ficus-indica) seed oil were studied. The most abundant fatty acid, tocopherol and sterol were linoleic acid (60.6%), γ-tocopherol (533 mg/kg) and β-sitosterol (6075 mg/kg), respectively. In this study, 23 volatile compounds were identified with perceivable odor attributes for 14 compounds. The oxidative quality of cactus seed oil was monitored over 4 weeks at 50 °C. Increases in PV, K232 and FFA were detected during the first two weeks as well as a decrease in the induction time; whereas no change was reported for the K270 values. The amount of total phenolic content increased until it reached 0.3 mg/kg and then decreased by the end of the storage period; while tocopherols started to decrease after the first week. The fat-free residue extracts showed a very strong effect to reduce the oxidation of linoleic acid. Consequently, the extracts were significantly more effective to bleach β-carotene in the β-carotene-linoleic acid assay in comparison with the control.

The intensity of the cluster drop affects the bioactive compounds and fatty acid composition in hazelnuts

O. Karakaya — jue, 16 mar 2023 00:00:00 +0100

This study was conducted to determine how the intensity of the cluster drop effects nut traits, bioactive compounds, and fatty acid composition in Tombul, Palaz and Kalınkara hazelnut cultivars. The cluster drop significantly affected bioactive compounds and fatty acid composition while it did not affect the traits of the nuts. As cluster drop intensity increased, nut traits and bioactive compounds in all cultivars increased. Strong cluster drop intensity determined the highest total phenolics, total flavonoids, and antioxidant activity. Except for the Kalınkara cultivar, a low amount of linoleic acid was detected while high amounts of oleic and stearic acid were determined in slight cluster drop intensity. As cluster drop intensity increased, palmitic acid increased. Principal component analysis showed that the slight and intermediate drop intensity were generally associated with kernel length, oleic, linoleic, stearic, palmitoleic, 11-eicosenoic and arachidic acids. In contrast, strong intensity was associated with nut and kernel weight, kernel ratio, kernel width, kernel thickness, kernel size, bioactive compounds, and palmitic acid. As a result, the bioactive compounds and fatty acid composition, which are important for human health, was significantly affected by cluster drop intensity.

Changes in the quality parameters of Cephalaria syriaca L. seed oil after the refining process

E. Duman — jue, 16 mar 2023 00:00:00 +0100

The present study has determined that the crude-oil refining process from the Cephalaria syriaca (CS) seed, which could be a new vegetable oilseed source, changed its physical and chemical quality properties (except specific gravity and refractive index). It was also determined that the dominant saturated and unsaturated fatty acids in the crude and refined oils were myristic (21.06-11.80%), palmitic (10.8-8.91%), stearic (2.26-2.70%), oleic (29.17-34.24%) and linoleic (35.56-40.57%). The vitamin E values of the crude and refined CS seed oils were 51.95-50.90 mg/kg, respectively. The oxidative stability values for crude and refined CS seed oils were 2.32-2.69 h, respectively. β-sitosterol and campesterol were the predominant sterols. As a result of the refining process, although magnesium, potassium, iron and copper decreased, the ratios of sodium, aluminum, calcium, chromium, strontium, rubidium, and barium increased. The results provide preliminary data for the future consumption of CS oil in particular for refined CS seed oil.

Fatty acid profile and rheological behavior of annatto seed oil (Bixa orellana), cupuassu seed fat (Theobroma grandiflorum), and their blends

mié, 22 mar 2023 00:00:00 +0100

Annatto seed oil (ASO) and cupuassu seed fat (CSF) were combined at the ratios: 30:70, 50:50, and 70:30 (% w/w). Their fatty acid profile, nutritional quality, FTIR (Fourier Transform Infrared) spectra, and rheological behavior were evaluated. ASO increased the content of polyunsaturated fatty acids in the blends; whereas CSF conferred higher contents of monounsaturated fatty acids. The blends exhibited low atherogenicity and thrombogenicity indices, suggesting nutritional advantages. The Newtonian fluid behavior and FTIR results suggested that mixing ASO and CSF at different proportions did not affect the functional groups. ASO showed an activation energy value which indicated that this fat viscosity was more sensitive to temperature changes. The Newtonian model proved to be suitable to describe the behavior of samples, according to statistical fit parameters R², χ², and RSS. The resulting blends presented improved physicochemical properties and nutritional attributes, indicating their feasibility for the development of new products.

The influence of microwave roasting on bioactive components and chemical parameters of cold pressed fig seed oil

D. Deniz Şirinyıldız, A. Yıldırım Vardin, A. Yorulmaz — vie, 24 mar 2023 00:00:00 +0100

The effect of microwave roasting process on the compositional parameters and bioactive contents of fig seed oil were investigated. Fig seeds were ground and roasted in a microwave oven at 350, 460 and 600 Watt for 5 and 10 minutes and the roasted seeds were processed to obtain oil. The results showed that peroxide, K₂₃₂ and K₂₇₀ values were adversely affected by roasting. Fig seed oil was a prosperous source of γ-tocopherol and significant losses were observed due to microwave pre-treatment. The major fatty acids in fig seed oil were linolenic, linoleic and oleic acids; whereas the major triacylglycerols were LnLO, LnLnL, LnLnLn and LnLnO, according to fatty acid profile. The most abundant sterol in the fig seed oil samples was β-sitosterol with 3235.90 to 3625.62 mg/kg, followed by Δ5- and Δ7-avenasterols. The principal component analysis and agglomerative hierarchial clustering served to differentiate between intense and mild microwave-treated oils as well as the unroasted samples.

Optimization of low thermal treatments to increase hydrophilic phenols in the Alperujo liquid fraction

M. Rodríguez, V. Cornejo, G. Rodríguez-Gutiérrez, P. Monetta — mié, 22 mar 2023 00:00:00 +0100

Hydrophilic phenols are the main bioactive compounds in alperujo. Among them, 3,4-Dihydroxyphenylglycol (DHPG), Hydroxytyrosol (HT) and Tyrosol (Ty), are the most relevant and deeply studied. These compounds exhibit high antioxidant capacity and a wide range of health benefits as well as technologically promising properties. Given that, their recovery represents an attractive opportunity to valorize this by-product. In this work low thermal treatments were applied to alperujo in order to obtain phenol-enriched liquid fractions. Optimization assays combining different levels of temperature (30 to 90 ºC), time (60 to 180 min) and water content (70 to 90%), followed by response surface methodologies were performed. The results indicated that by applying optimal conditions, is possible to obtain theoretical yields of Total phenols, DHPG, HT and Ty of 2.4, 957.8, 3.4 and 6.4 times greater, respectively, than raw dry alperujo. Interestingly, all the evaluated conditions can be reproduced with low investment in a standard olive oil industry.

Extraction of bioactive lipids from Pleuroncodes monodon using organic solvents and supercritical CO2

mié, 22 mar 2023 00:00:00 +0100

A huge volume of Engraulis ringens (Peruvian anchoveta) is caught together with the species Pleuroncodes monodon (munida), whose potential bioactive lipids are not commercially exploited. In the present study, lipid with carotenoid pigment (astaxanthin) and essential fatty acids (EPA+DHA) were obtained from munida lipids extracted with hexane:isopropyl alcohol (He-I), acetone (Ac), ethanol (Et) and supercritical CO₂ + ethanol (SC-CO₂-Et). The functional quality of the fatty acids was determined by atherogenicity index (AI), thrombogenicity index (TI) and the hypocholesterolemia:hypercholesterolemia (H:H) ratio. The highest astaxanthin (ASTX) contents (4238.65 and 4086.71 µg/g lipid) corresponded to extractions using Ac and SC-CO₂-Et. EPA+DHA ranged from 31.15 to 31.85% and the functional quality ranges were between 0.56-0.61 (AI), 0.19-0.21 (TI) and 1.73-1.81 (H:H). Consequently, SC-CO₂-Et extraction would be advisable because of its low environmental impact. The IA and IT quality indexes suggest that the consumption of munida lipids would be healthy, although the H:H ratio shows the opposite.

Oxidative stability and compositional characteristics of oil from microwave irradiated black cumin seed under accelerated oxidation condition

J. Hossen, M. Abbas Ali, N. Hidayu Othman, A. Md Noor — mié, 22 mar 2023 00:00:00 +0100

The present work evaluated the impact of microwave pre-treatment on the storage stability, fatty acids and triacylglycerol contents in black cumin seed oil (BCO) during storage at 62 ºC. During storage, the oxidative indicator values (free acidity, peroxide value, p-anisidine value, TOTOX, specific extinctions and thiobarbituric acid) for the oils increased faster in untreated oil samples than in the microwaved samples. The degradation rate of polyunsaturated fatty acids (PUFAs) and triacylglycerol species (LLL and OLL) during storage were higher in untreated samples compared to treated ones, indicating that oxidation proceeded more slowly in the treated samples. During storage, the generation of hydroperoxides, their degradation and the formation of secondary oxidation products as investigated by FTIR, were lower in the treated oils. In conclusion, microwave pre-treatment prior to oil extraction reduced the oxidative degradation of oil samples, thereby increasing the storage stability of BCO.

The effects of processing aids and techniques on olive oil extractability and oil quality índices

E. Khaleghi, H. Norozi Moghadam, S.M.H. Mortazavi — jue, 16 mar 2023 00:00:00 +0100

This study was conducted to investigate the effects of processing aids and techniques such as talcum powder (2% w/w), calcium carbonate (2% w/w), warm water dipping (45 °C), combined treatment (warm water dipping+2% calcium carbonate) and control (without adding processing aid) on extractability and quality of ‘Tarom 7’ olive oil as randomized complete block design with three replicates. The results showed that there were no significant differences in the carotenoid content, K₂₃₂, fatty acid profile or the Cox’s value in the oil obtained from untreated and treated fruits with processing aids. The highest chlorophyll content (0.84 mg/kg), total phenolic content (236.94 mg/kg), paste extractability (8.5%) and the lowest peroxide values (0.32 meqO₂/kg), K₂₇₀ (0.38) were obtained from the oil extracted with 2% talc powder. According to the results, it can be suggested that the 2% talc powder treatment could have a positive effect on olive oil quality and paste extractability.

Preparation of human milk fat substitute and improvement of its oxidative stability

vie, 24 mar 2023 00:00:00 +0100

1,3-Dioleoyl-2-palmitoylglycerol (OPO) was synthesized by enzymatic interesterification using palm stearin rich in tripalmitin (PPP) and ethyl oleate. Enzymatic interesterification parameters such as temperature, water content, enzyme load, and substrate molar ratio were optimized. High contents of C52 (primarily OPO and its isomeric compounds) production (46.7%) and sn-2 palmitic acid (PA) content of 75.3% were detected. In addition, OPO-human milk fat substitute (HMFS) was blended with coconut, soybean, algal and microbial oils at a weight ratio of 0.70:0.18:0.11:0.004:0.007 to simulate fatty acids in human milk fat (HMF) according to the mathematical model. The main and important fatty acids in the Final-HMFS were within the ranges of those present in HMF. The Final-HMFS could promote the absorption of fats and minerals and the development of retina tissues in infants. The mixture of L-ascorbyl palmitate (L-AP) and vitamin E (VE) resulted in a synergistic antioxidant effect both in OPO-HMFS and OPO-HMFS emulsions. This finding has great significance in improving the quality and extending shelf-life of HMFS.

Extraction of oil, carotenes and tocochromanols from oil palm (Elaeis guineensis) fruit with subcritical propane

H. Phan-Tai, G. Brunner — vie, 24 mar 2023 00:00:00 +0100

This work aims to screen the extraction of oil and bioactive compounds including carotenes and tocochromanols from oil palm fruit with subcritical propane and without using a cosolvent. The overall extraction curves of palm oil with subcritical propane were studied and compared to those extracted with supercritical carbon dioxide. Carotenes and tocochromanols were evaluated not only in the extracted oil, but also in the oil of residual fiber in order to calculate the efficiency to recover these valuable compounds. The experimental results showed that oil yield of up to 70 % could be obtained within 120 minutes with subcritical propane at 50 bar and a flow rate of 35 kg·h⁻¹·kg⁻¹. It was also shown that compressed propane is an excellent solvent for the extraction of oil enriched in carotenes and tocochromanols. Subcritical propane extraction can be used as an alternative process for the simultaneous recovery of these valuable minor components from palm fruit.

Changes in the essential oil content and composition of pelargonium graveolens l’hér with different drying methods

S. Akçura, R. Çakmakçi, Z. Ürüşan — jue, 23 mar 2023 00:00:00 +0100

In this study, the effect of various drying methods (fresh plant, shade-drying, sun-drying, and oven-drying at 30 and 60 °C) on the essential oil (EO) composition of rose-scented geranium were determined. Essential oil samples were extracted by hydrodistillation and analyzed by GC and GC-MS systems. The highest EO contents were obtained in the fresh plant (1.98%), followed by shade-drying (1.34 %) and oven-drying at 30 °C (1.20 %). The main components were citronellol (23.99-39.87%), geraniol (4.15-17.09%), menthone (4.48-8.34%), linalool (1.96-7.42%), β-caryophyllene (2.63-4.32%), geranyl tiglate (0.99-4.52%), citronellyl butyrate (0.53-5.31%) and cis-rose oxide (0.71-3.15%). The drying methods showed a marked impact on the constituents of the EO samples. The results demonstrated that drying the aerial parts of fresh geranium, and shade-drying and oven-drying at 30 °C were the best optimal methods to obtain the highest oil yield, and citronellol, geraniol, and linalool contents in the oil.