A novel method for determination of peroxide value and acid value of extra-virgin olive oil based on fluorescence internal filtering effect correction.

Peroxide value (PV) and acid value (AV) are widely used indicators for evaluating oxidation degree of olive oils. Fluorescence spectroscopy has been extensively studied on the detection of oil oxidation, however, the detection accuracy is limited due to internal filtering effect (IFE). Due to the primary and secondary IFE, at least two wavelengths of absorption information are required. Least squares support vector regression (LSSVR) models for PV and AV were established based on two absorption coefficients (µa) at 375 nm and emission wavelength and one fluorescence intensity at corresponding wavelength. The regression results proved that the model based on 375 and 475 nm could reach the best performance, with the highest correlation coefficient for prediction (rp) of 0.889 and 0.960 for PV and AV respectively. Finally, the explicit formulations for PV and AV were determined by nonlinear least squares fitting, and the rp could reach above 0.94 for two indicators.

The bioprotective role of irradiated hibiscus against harmful effects of using repeatedly frying edible oil

Abstract Repeatedly frying process of dietary edible oil has a potential role in the generation of free radicals. Therefore, questions have always been raised as to whether, there is an efficient and economical method to reduce the harmful effects of repeated use of frying edible oil. Since hibiscus has been stated to have a wide variety of therapeutic effects, it was important to investigate its properties against harmful effects of free radicals. The current study aspires to find out whether irradiated powder of hibiscus has a protective role against adverse effects of repeated use of frying edible oil. Thirty-five adult male albino rats were equally assigned into five groups. First groupG1 was fed with normal diet as control group, meanwhile, groupG2 the diet mixed with fresh oil, G3 diet mixed with repeatedly frying oil only, G4 diet mixed with frying oil treated with hibiscus and G5 diet mixed with frying oil treated with irradiated hibiscus. Feeding duration was six weeks. Fatty acid analyses of oil as well as peroxide values were determined. Blood and liver samples were collected for biochemical analyses as well as histological study. Repeatedly heated cooked oil has significant increases in peroxide value, acid value, free fatty acid and both conjugated diene and triene compared with repeatedly frying oil treated with hibiscus. Also there are significant increases in cholesterol and triglyceride and impaired in liver functions in G3compared with others. In addition, relative to the hibiscus groups, there is a substantial reduction in oxygen consumption in G3. Both hibiscus as well as irradiated hibiscus attract attention in order to play a vital and economical role against harmful effects of frequent use of frying edible oil on some biological functions but, irradiated hibiscus was more effective.

Resumo O processo de fritura repetida de óleo comestível da dieta tem papel potencial na geração de radicais livres que podem ter efeitos prejudiciais em algumas funções biológicas. Portanto, sempre se questionou se existe uma maneira eficiente e econômica de prevenir ou pelo menos reduzir os efeitos nocivos do uso repetido de óleo comestível para fritar. Como o hibisco tem ampla variedade de efeitos terapêuticos, foi importante investigar suas propriedades como agente antioxidante contra os efeitos nocivos dos radicais livres. O presente estudo pretende descobrir se o pó irradiado de hibisco tem papel protetor contra os efeitos adversos do uso repetido de óleo comestível para fritar. Trinta e cinco ratos albinos machos adultos foram divididos igualmente em cinco grupos. O primeiro grupo G1 foi alimentado com dieta normal como grupo controle, enquanto o grupo G2 dieta misturada com óleo fresco, dieta G3 misturada com óleo de fritura repetida, dieta G4 misturada com óleo de fritura tratada com hibisco e dieta G5 misturada com óleo de fritura tratada com hibisco irradiado. A duração da alimentação foi de seis semanas. Foram determinadas as análises de ácidos graxos de óleo, bem como os valores de peróxidos. Amostras de sangue e fígado foram coletadas para análises bioquímicas e estudo histológico. O óleo cozido repetidamente aquecido tem aumentos significativos no valor de peróxido, valor de ácido, ácido graxo livre e dieno e trieno conjugados em comparação com óleo de fritura repetidamente tratado com hibisco. Também há aumentos significativos no colesterol e triglicérides e comprometimento das funções hepáticas no G3 em comparação com outros. Além disso, em relação aos grupos de hibiscos, há uma redução substancial no consumo de oxigênio no G3. Tanto o hibisco como o hibisco irradiado chamam atenção por desempenhar papel vital e econômico contra os efeitos nocivos do uso frequente de óleo comestível para fritar em algumas funções biológicas, mas o hibisco irradiado foi mais eficaz.

The bioprotective role of irradiated hibiscus against harmful effects of using repeatedly frying edible oil / O papel bioprotetor do hibisco irradiado contra os efeitos nocivos do uso de óleo comestível para fritar

Abstract Repeatedly frying process of dietary edible oil has a potential role in the generation of free radicals. Therefore, questions have always been raised as to whether, there is an efficient and economical method to reduce the harmful effects of repeated use of frying edible oil. Since hibiscus has been stated to have a wide variety of therapeutic effects, it was important to investigate its properties against harmful effects of free radicals. The current study aspires to find out whether irradiated powder of hibiscus has a protective role against adverse effects of repeated use of frying edible oil. Thirty-five adult male albino rats were equally assigned into five groups. First group"G1" was fed with normal diet as control group, meanwhile, group"G2" the diet mixed with fresh oil, "G3" diet mixed with repeatedly frying oil only, "G4" diet mixed with frying oil treated with hibiscus and "G5" diet mixed with frying oil treated with irradiated hibiscus. Feeding duration was six weeks. Fatty acid analyses of oil as well as peroxide values were determined. Blood and liver samples were collected for biochemical analyses as well as histological study. Repeatedly heated cooked oil has significant increases in peroxide value, acid value, free fatty acid and both conjugated diene and triene compared with repeatedly frying oil treated with hibiscus. Also there are significant increases in cholesterol and triglyceride and impaired in liver functions in "G3"compared with others. In addition, relative to the hibiscus groups, there is a substantial reduction in oxygen consumption in "G3". Both hibiscus as well as irradiated hibiscus attract attention in order to play a vital and economical role against harmful effects of frequent use of frying edible oil on some biological functions but, irradiated hibiscus was more effective.

Resumo O processo de fritura repetida de óleo comestível da dieta tem papel potencial na geração de radicais livres que podem ter efeitos prejudiciais em algumas funções biológicas. Portanto, sempre se questionou se existe uma maneira eficiente e econômica de prevenir ou pelo menos reduzir os efeitos nocivos do uso repetido de óleo comestível para fritar. Como o hibisco tem ampla variedade de efeitos terapêuticos, foi importante investigar suas propriedades como agente antioxidante contra os efeitos nocivos dos radicais livres. O presente estudo pretende descobrir se o pó irradiado de hibisco tem papel protetor contra os efeitos adversos do uso repetido de óleo comestível para fritar. Trinta e cinco ratos albinos machos adultos foram divididos igualmente em cinco grupos. O primeiro grupo "G1" foi alimentado com dieta normal como grupo controle, enquanto o grupo "G2" dieta misturada com óleo fresco, dieta "G3" misturada com óleo de fritura repetida, dieta "G4" misturada com óleo de fritura tratada com hibisco e dieta "G5" misturada com óleo de fritura tratada com hibisco irradiado. A duração da alimentação foi de seis semanas. Foram determinadas as análises de ácidos graxos de óleo, bem como os valores de peróxidos. Amostras de sangue e fígado foram coletadas para análises bioquímicas e estudo histológico. O óleo cozido repetidamente aquecido tem aumentos significativos no valor de peróxido, valor de ácido, ácido graxo livre e dieno e trieno conjugados em comparação com óleo de fritura repetidamente tratado com hibisco. Também há aumentos significativos no colesterol e triglicérides e comprometimento das funções hepáticas no "G3" em comparação com outros. Além disso, em relação aos grupos de hibiscos, há uma redução substancial no consumo de oxigênio no "G3". Tanto o hibisco como o hibisco irradiado chamam atenção por desempenhar papel vital e econômico contra os efeitos nocivos do uso frequente de óleo comestível para fritar em algumas funções biológicas, mas o hibisco irradiado foi mais eficaz.

How heated vegetable oil age? Effect of the container of heating on ageing.

This study compares the ageing process of heated oil with unheated oil and assesses the effect of container used in heating on ageing. Four types of oils were heated on glass, copper and iron. The samples were allowed to age for 1 year. Unheated oils generally produce peroxide faster (for unheated maximum increase in 6-month is 2907 % from 1.351 to 40.627 but for heated maximum increase is 6574 % from 1.91 to 127.476). But they develop secondary oxidation products slowly (for unheated maximum increase in 6-month is 884 % from 1.553 to 15.29 but for heated maximum increase is 191 % from 6.42 to 18.72). For most oil heating in copper produce more p-anisidine value during ageing. The acid value of only unheated oils decreases between 6 months to 1 year. For the 1st six-month rate of increase in saponification value in unheated oil is much higher. The DPPH inhibition activity also changes differently.

Physicochemical characteristics and shelf-life stability of soya bean oil-based shortening.

The use of animal fats as raw material for shortening production has been avoided because of low supply, and religious restrictions of certain beliefs. The use of hydrogenated vegetable oils is also avoided because that may induce cardiovascular diseases. Palm oils and soya bean oil are theoretically potentials to be used as raw materials for shortening manufacturing due to their triacylglycerols composition and these oils can be easily modified to achieve desirable plasticity. In this study, shortening was produced by formulating a blend of palm stearin and soya bean oil in varying proportions. Physicochemical properties, product stability, and sensory acceptability of the processed shortening were determined. Stability tests of the processed shortening were determined for 6 months at two months intervals. The acidity, peroxide value, and free fatty acid values were increased with storage time and storage temperature. The physicochemical properties of the processed shortening samples were within the requirements of the food domain. The samples stored at 37 °C exhibited the highest acid, peroxide, and free fatty acid values throughout storage time. In conclusion, shortening produced from 60% palm stearin (S60) and stored at room temperature has shown a good physicochemical characteristic and is well accepted for different sensory attributes.

The Effects of Heat Treatment on the Oxidation Resistance and Fatty Acid Composition of the Vegetable Oil Blend.

The purpose is to elucidate the effects of the duration of heat treatment on the resistance of vegetable oils to oxidative processes. Iodine and acid values were analyzed before and after heat exposure. Rapeseed oil, sunflower oil, and a blend of rapeseed and sunflower oils (ratio 55:45) were used as samples. Sunflower oil heated at a temperature of 40°C for 80 minutes had its peroxide value increased by 3.0 times (p ≤ 0.05) as compared to rapeseed oil and the blend. At 75°C, the peroxide value increased by 4.0 times for sunflower oil (p ≤ 0.05), by 3.0 and 3.3 times for rapeseed oil (p ≤ 0.05), and by 3.1 and 3.4 times for the blend (p ≤ 0.05). At 40°C, no peroxide values were obtained that exceeded the threshold limits. The concentration of fatty acids in oils depends on the plant variety, growth conditions and maturity of seeds or fruits. Therefore, the concentration of fatty acids in the oil should be measured before oil blending.

Non-destructive method to classify walnut kernel freshness from volatile organic compound (VOC) emissions using gas chromatography-differential mobility spectrometry (GC-DMS) and machine learning analysis.

Analysis of volatile organic compounds (VOCs) can be an effective strategy to inspect the quality of horticultural commodities and following their degradation. In this work, we report that VOCs emitted by walnuts can be studied using gas chromatography-differential mobility spectrometry (GC-DMS), and those GC-DMS data can be analyzed to predict the rancidity of walnuts, i.e., classify walnuts into grades of freshness. Walnut kernels were assigned a class n depending on their level of freshness as determined by a peroxide assay. VOC samples were analyzed using GC-DMS. From these VOC data, a partial least square regression (PLSR) model provided a freshness prediction value m, which corresponded to the rancid class n when m=n±0.5. The PLSR model had an accuracy of 80% to predict walnut grade and demonstrated a minimal root mean squared error of 0.42 for the m response variables (representative of walnut grade) with the GC-DMS data. We also conducted gas chromatography-mass spectrometry (GC-MS) experiments to identify volatiles that emerged or were enhanced with more rancid walnuts. The findings of the GC-MS study of walnut VOCs align excellently with the GC-DMS study. Based on our results, we conclude that a GC-DMS device deployed with a pre-trained machine learning model can be a very effective device for classifying walnut grades in the industry.

Lipid oxidation in fragrant rapeseed oil: Impact of seed roasting on the generation of key volatile compounds.

This work sought to identify the influence of roasting on lipid oxidation-derived volatile compounds in fragrant rapeseed oils (FROs) via gas chromatography-mass spectrometry and gas chromatography-ion mobility spectrometry. Seven volatiles could be regard as aroma-active compounds by application of odor activity value (OAV ≥ 1) calculation, and caused fatty-like, nutty-like, and green-like notes. After 60 min of roasting, the OAVs of hexanal, octanal, (E,E)-2,4-heptadienal, and nonanal in FROs were greater than 3. The same compounds, including hexanal, (E,E)-2,4-heptadienal, nonanal, 1-octanol, and nonanoic acid were also detected in the model systems of lipid oxidation. Notably, the values of p-anisidine, conjugated dienes, and conjugated trienes increased significantly (p < 0.05). Furthermore, correlation analysis showed that hexanal, (E,E)-2,4-heptadienal, and nonanal have a significant positive correlation with the oxidative degree of FROs (R = 0.70-0.94, p < 0.05). Thus, the three above-mentioned aldehydes could serve as important markers for FRO quality during roasting.

Mayonnaise Enriched with Flaxseed Oil: Omega-3 Fatty Acids Content, Sensory Quality and Stability during the Storage.

This study aimed to produce healthy mayonnaise with a protective effect against cardiovascular diseases, containing omega-3 fatty acids (FA), using flaxseed oil (FXO), which includes a high percentage of alpha-linolenic acid (ALA, C18:3n-3). The mayonnaise was prepared by replacing soybean oil with FXO at 20, 30, and 40% levels. The effect on the organoleptic, physical, and chemical quality was studied compared to a control, prepared only with soybean oil (70%). The oxidative and microbial stability during 12 weeks of storage at 25 and 7 °C was also evaluated. The results showed that the use of FXO in mayonnaise (20, 30, and 40%) led to an increase in TUFA (from 79.37 (control) to 82.48, 85.49, and 87.66%, respectively), particularly in PUFAn-3, due to the rise of ALA (from 6.5 to 18.38, 24.02 and 37.87%, respectively) and a decrease in TSFA (from 20.63 to 17.52, 14.51 and 12.34%, respectively). The panelists did not perceive significant differences in the sensory characteristics of the "new" mayonnaise. A decrease in the oxidation rates of the "new" mayonnaise during the storage period was observed. A significant effect on microbial growth was not reported, although the permissible limits were not exceeded after 12 weeks of storage, even at 25 °C.

Evaluation of the Effect of Elite Jojoba Lines on the Chemical Properties of their Seed Oil.

Jojoba oil (JO) extracted from seeds has outstanding properties, including anti-inflammatory, antioxidant, and antibacterial activities, and can be stored forlong periodsof time. The unique properties of jojoba oil depend on its chemical composition; therefore, the effect of the jojoba genotype on the chemical properties and active components of the seed oil was evaluated in this study. Oil samples were collected from 15 elite Egyptian jojoba lines. The chemical composition, such as moisture, crude fiber, crude oil, ash, and crude protein of elite lines' seeds was determined to investigate the variation among them based on the jojoba genotype. In addition, the iodine value was obtained to measure the degree of jojoba oil unsaturation, whereas the peroxide number was determined as an indicator of the damage level in jojoba oil. Fatty acid composition was studied to compare elite jojoba lines. Fatty acid profiles varied significantly depending on the jojoba genotype. Gadoleic acid exhibited the highest percentage value (67.85-75.50%) in the extracted jojoba oil, followed by erucic acid (12.60-14.81%) and oleic acid (7.86-10.99%). The iodine value, peroxide number, and fatty acid composition of the tested elite jojoba lines were compared withthose reported by the International Jojoba Export Council (IJEC). The results showed that the chemical properties of jojoba oils varied significantly, depending on the jojoba genotype.

Utilization of Diaphragma juglandis extract as a natural antioxidant for improving the oxidative stability of soybean oil during deep frying.

Lipid oxidation significantly shortens the life of frying oils, and this challenge can be addressed by using antioxidants. This work aimed to investigate the effect of Diaphragma juglandis extract (DJE) on the oxidative stability of soybean oil during deep frying. Tert-butylhydroquinone (TBHQ) and tea polyphenol (TP) were applied as positive controls. A total of 31 polyphenols were determined in DJE, and catechin, quercitrin, taxifolin, quercetin 3-ß-d-glucoside, epicatechin, gallic acid, and 3,4-dihydroxybenzoic acid were the main components. The antioxidants effectively delayed the degradation of triglycerides and inhibited the increase in the contents of p-anisidine, oxidized triglyceride monomers, triglyceride dimers, and triglyceride oligomers, with DJE exhibiting better performance. Moreover, DJE showed better inhibitory effect on the formation of (E)-2-alkenals, (E,E)-2,4-alkadienals, 4-oxo-alkanals, primary alcohols, and secondary alcohols detected by 1H nuclear magnetic resonance than TBHQ and TP. Therefore, DJE has great potential as an excellent antioxidant in large-scale industrial applications.

Effect of Light on the Oxidative Stability and Phthalate Levels of Black Cumin Oil-Corn Oil Blends in Plastic and Glass Bottling.

Black cumin oil (BC) contains certain phytochemicals, including phenolics, tocopherols, and sterols, which show strong oxidation stability. In this study, BC was blended with refined corn oil (CO) at two concentrations (5% and 10%, w/w) and stored in plastic and glass bottles under light and dark conditions. Under light-storage conditions, blended oils in plastic bottles showed lower peroxide value (PV) and conjugated diene value (CD) compared to the control sample than dark-storage. It was also aimed to examine the phthalate levels in oil samples and evaluate the products' safety. Five main phthalates, namely di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), butyl-benzylphthalate (BBP), diisononyl phthalate (DiNP), and diisodecyl phthalate (DiDP), were evaluated. In dark and light storage conditions, the phthalate level was determined below the LOQ value in CO without added BCO in the plastic and glass bottles. In the plastic-packaged blended samples, DEHP was determined above the LOQ value in dark storage, while BBP was detected in addition to DEHP in the samples stored under the light. On the other hand, phthalate values were determined below the LOQ value in all samples stored in glass packages under the light. DEHP was the most abundant phthalate in plastic-packaged blended oils under light storage, ranging from below the LOQ (0.23 mg/kg) to 0.83 mg/kg. Based on the present findings, BC improved the stability of CO under light storage, and the phthalate levels of blended oils did not exceed the specific migration limits (SMLs) for each phthalate.

Effects of active batter coatings enriched by quince seed gum and carvacrol microcapsules on oil uptake and quality loss of nugget during frying.

ABSTRACT: The effects of active batter coatings containing quince seed gum (QSG) and carvacrol microcapsules (CM) on oil uptake, moisture loss, lipid oxidation, texture, color and organoleptic properties of chicken nuggets during the frying process were investigated. Active coatings on the surface of nuggets reduced oil uptake and moisture loss of fried samples decreased by 33.21% and 29.64%, respectively. Antioxidant activity tests showed that oxygen radical absorbance capacity (ORAC) and DPPH radicals scavenging activity of carvacrol microcapsules were 152.23 ± 4.11 µmol TE/g, and 51.09 ± 3.32%, respectively. Investigation of primary and secondary oxidation products in the fried nugget samples showed that the peroxide value and thiobarbituric acid levels in control samples were 7.43 meq peroxide/kg and 1.35 mg MDA/kg, respectively. The results of this study showed that the highest reduction in PV and TBA were 41.85 and 37.04% for the QSG-coated samples containing 1% carvacrol microcapsules. The color of QSG-coated samples did not change significantly compared to control samples, although their hardness was reduced compared to the control samples (p < 0.05). The results showed that the use of active edible coatings made from quince seed gum and containing carvacrol microcapsules did not show any negative effects on the sensory properties of nuggets.

Application of NIR spectroscopy for rapid quantification of acid and peroxide in crude peanut oil coupled multivariate analysis.

Two key parameters (acidity and peroxide content) for evaluation of the oxidation level in crude peanut oil have been studied. The titrimetric analysis was carried out for reference data collection. Then, near-infrared spectroscopy in combination with chemometric algorithms such as partial least square (PLS); bootstrapping soft shrinkage-PLS (BOSS-PLS); uninformative variable elimination-PLS (UVE-PLS), and competitive-adaptive reweighted sampling-PLS (CARS-PLS) were attempted and assessed. The correlation coefficients of prediction (Rp), root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) were used to individually evaluate the performance of the models. Optimum results were noticed with CARS-PLS, 0.9517 ≤ Rc ≤ 0.9670, 0.9503 ≤ Rp ≤ 0.9637, 0.0874 ≤ RMSEP ≤ 0.5650, and 3.14 ≤ RPD ≤ 3.64. Therefore, this affirmed that the near-infrared spectroscopy coupled with CARS-PLS could be used as a simple, fast, and non-invasive technique for quantifying acid value and peroxide value in crude peanut oil.

Application of Oleogel and Conventional Fats for Ultrasound-assisted Obtaining of Vegan Creams.

The purpose of this study was to determine the impact of the fat system type (milk fat - MF, palm oil - PO or oleogel - OG, i.e. RO-LO - rapeseed oil and linseed oil mixture structured by candelilla wax) on the properties of soy creams, in comparison with dairy cream. The MF exhibited the most increase of acid value (2.5-fold), and the RO-LO - increase of peroxide value (3-fold), after 30 days of storage at 20°C. The PO was the most oxidative stable. The OG presented the slightest oxidative changes, the highest slip melting point (39°C) and centrifugal stability (99.6%). The pH and total acidity values of soy creams were similar to soy drink. All creams exhibited unimodal distribution of dispersed particles. The average particle size and dispersity indexes of these emulsions were in range of 1.74-1.80 µm and 0.93-1.16, respectively. The creams with MF or OG exhibited a greater viscosity than sweet dairy cream - 1.66 10-5 nm-2, and a higher degree of shear-thinning. The accelerated creaming phenomenon (flotation of lipids molecules) occurred during centrifugation. The cream with PO had the lowest resistance to centrifugal force (instability index - 0.052). The possibility to obtain a stable vegan soy creams containing oleogel (as replacer of conventional fats) has been demonstrated.

Comparative analysis on the bleaching of crude palm oil using activated groundnut hull, snail shell and rice husk.

Researchers have found out several ways by which environmental pollution can be of positive relevance by recycling the waste to ensure a cleaner and healthier environment. The bleaching process is a crucial process in palm oil refining in which an adsorbent is majorly used to adsorb the unwanted colour pigments and a wide range of other impurities. This study aims to modify three different adsorbents; Groundnut hull, Snail shell, and rice husk and processed them into powder form as Groundnut hull powder [GHP], Snail shell powder [SSP] and Rice husk powder [RHP] respectively. The effects of three factors: temperature, mass and time were investigated on the response. MINITAB 19 software was employed which resulted in 20 runs. The optimization of the bleaching effects imposed by the adsorbents on palm oil using Central Composite Design (CCD) was evaluated. The free fatty acid and peroxide value decrease with bleaching while the saponification value increased with bleaching. The analysis conducted shows that groundnut hull was able to adsorb the most significant value of FFA and peroxide value in the palm oil. The lowest value of FFA obtained indicates that bleaching increases the shelf life of the oil and makes it more suitable for soap making.

Characterization of Fungi Associated with Olive Fruit Rot and Olive Oil Degradation in Crete, Southern Greece.

In November 2019, a severe outbreak of fruit rot was observed in olive orchards in Crete, southern Greece. Symptoms appeared primarily on fruits and stalks, resembling those caused by anthracnose. Typical symptoms were fruit rot, shrinkage, and mummification, associated commonly with stalk discoloration and fruit drop. Disease incidence was estimated at up to 100% in some cases, and an unprecedented increase in olive oil acidity reaching up to 8% (percentage of oleic acid) in severely affected olive groves was recorded. Thirty-two olive groves were then surveyed, and samples of fruit, stalk, leaf, and shoot were collected. Visual, stereoscopic, and microscopic observations revealed several fungi belonging to the genera Alternaria, Botryosphaeria, Capnodium, Colletotrichum, Fusarium, and Pseudocercospora. Fungal infection in fruits was commonly associated with concomitant infestation by the olive fruit fly Bactrocera oleae along with increased air temperature and relative humidity conditions that prevailed in October and November 2019. Twenty representative fungal strains isolated from symptomatic fruits and stalks were characterized by morphological, physiological, and molecular analyses. By internal transcribed spacer regions of ribosomal DNA region and translation elongation factor 1-α gene sequencing analysis, these isolates were identified as Alternaria spp., A. infectoria, Botryosphaeria dothidea, Colletotrichum boninense sensu lato, Fusarium lateritium, F. solani species complex and Stemphylium amaranthi. Pathogenicity tests on punctured fruits revealed that all isolates were pathogenic; however, F. solani isolates along with B. dothidea were the most virulent, and wounds were necessary for efficient fungal infection. Moreover, as few as 10 spores of F. solani were sufficient to cause significant infection in punctured fruits. F. solani was also capable of infecting olive fruits in the presence of B. oleae, with no additional wounding, in artificial inoculation experiments. Moreover, it was capable of colonizing and affecting olive blossoms. Further analyses of olive oil extracted from fruits artificially inoculated with F. solani indicated a significant increase in oil acidity, K232, K270, and peroxide value, whereas total phenol content was significantly decreased. To the best of our knowledge, this is the first report of F. solani associated with olive fruit rot and olive oil degradation worldwide.

Walnut (Juglans regia L.) Volatile Compounds Indicate Kernel and Oil Oxidation.

Kernel oxidation susceptibility and pellicle darkening are among the biggest concerns regarding walnut quality. Monitoring oxidation is crucial to preserve quality from production to consumption. Chemical oxidation parameters (peroxide value and UV absorbances), fatty acid profile, tocopherols, phenols, and volatiles in 'Chandler' and 'Howard' kernels were studied at different time points during 28 weeks of storage to evaluate potential oxidation markers. During storage, peroxide value, UV absorbances, and volatiles concentration increased; oxidative stability, phenols, and tocopherols decreased, while fatty acid profile was unaffected. 'Chandler' had a lower peroxide value, K232, and K268; and higher kernel and oil oxidative stability compared to 'Howard'. Phenols and tocopherols decreased 1.2-fold in 'Chandler' and 1.3-fold in 'Howard'. Using multivariate analysis, samples were discriminated in three groups according with their oxidative levels. Increases of volatiles in oil and kernel were associated with higher oxidative levels. Pentanal, 2-methylpropanal, hexanal, (E)-2-pentenal, 3-octanone, octanal, (Z)-2-penten-1-ol, hexanol, (E)-2-octenal, 1-octen-3-ol, benzaldehyde, (E,E)-2,4-nonadienal, and hexanoic acid in kernels were adequate at distinguishing oxidation levels and as oxidative markers in walnuts. Kernel volatiles is a useful measurement for walnut oxidation during storage without any prior fat extraction.

Optimum Processing Conditions for Bakasang Using the Response Surface Methodology with Central Composite Design (CCD).

<b>Background and Objective:</b> Bakasang is a typical food of North Sulawesi and its surroundings, made from fermented fish viscera. This food is made by fermentation so that it is rich in amino acids and polypeptides. This study aimed to determine the optimum processing conditions for Bakasang with Peroxide Value (PV) parameters based on Response Surface Methodology (RSM) with Central Composite Design (CCD). <b>Materials and Methods:</b> Viscera from fresh Skipjack tuna consisting of intestines, liver, heart and eggs were mixed with salt and left in a fermenter for varying times and temperatures to obtain Bakasang. The fermentation temperature, salt content, and fermentation time, determined based on the Central Composite Design (CCD), were variables in this study. Thus, 20 experiments consisted of eight quadratic points, six centre points and six axial points. <b>Results:</b> The results showed that the correlation test between temperature, salinity and fermentation time variables on PV were 0.521, 0.305 and 0.591. The regression test resulted in an R² value of 0.988. The model equation obtained was y = 4.35194 - 0.11363x₁- 0.07459x₂- 0.25300x₃+ 0.00157x₁₂+ 0.00310x₂₂ + 0.01571x₃₂ - 0.00064x₁x₂+ 0.00172x₁x₃ + 0.00340x₂x₃. The contour plot graph obtained from the experiment using CCD showed that the optimum processing conditions for Bakasang were at a temperature of 32.9324°C, salinity 10.2631% and fermentation time of 4.7793 days, which will produce Bakasang with an optimum PV of 1.51256 meq kg¹ sample. <b>Conclusion:</b> According to the findings of this study, the optimum temperature, salinity and fermentation time for producing Bakasang with a PV of 1.51256 meq kg¹ sample were 32.932°C, 10.263% and 4.779 days, respectively.

The shelf life of buffalo meat marinated with pomegranate (Punica granatum) peel extract.

OBJECTIVE: The purpose of this study was to investigate how pomegranate peel extract (PPE) can prevent lipid oxidation, peroxide value, and pathogenic bacteria growth in buffalo meat. MATERIALS AND METHODS: PPE and buffalo meat were employed in this investigation. The buffalo meat marinated with PPE was evaluated by refrigerating it at a temperature of 5°C ± 1°C on days 0, 4, 8, 12, and 16. PPE was added to buffalo meat at a rate of 0% as a control (K0), 0.50% (K1), 1.00% (K2), 1.50% (K3), and 2.00% (K4). RESULTS: The addition of PPE lowered the total plate count, peroxide value, lipid, and pH between treatments and storage period (p < 0.05). PPE's high concentration of polyphenols, flavonoids, antioxidants, and antibacterial substances may decrease lipid oxidation, peroxide production, and bacterial growth rate. CONCLUSIONS: Marinating buffalo meat in PPE may help maintain the meat's freshness while being stored at a refrigerator temperature (5°C ± 1°C).