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Graphical Abstract: In this study, the role of oven and microwave roasting on the oil, chlorophyll, total phenol, flavonoid contents, antioxidant activities (DPPH and FRAP assays), specific absorbance (K232, K270) values, phenolic profile and fatty acid compositions of rapeseed was revealed

Graphical abstract: In this study, the effect of the application of salt water (brine), oak wood ash and caustic (NaOH) on salt content, acidity, pH in caper brine during fermentation and to determine the moisture, bioactive properties (antioxidant). activity, total phenol carotenoid, flavonoid), phenolic constituents and sensory characteristics of caper buds using hot water as an alternative to the bittering process with normal water in the production of fermented caper budswas investigated

In this study, the effects of roasting chia seeds at different temperatures (90 and 120 °C) on total phenol, flavonoid, and carotenoid contents and antioxidant activities were examined. Additionally, the effects of different extraction methods on the phenolic components of chia seeds and the chemical properties and fatty acids of chia seed oils were investigated. Chia seed oil was extracted via Soxhlet without roasting as control, yielded 29.62%. The oils from seeds roasted at 90 °C and 120 °C had yields of 32.65% and 33.85%. The control oil had an acidity value of 4.70%. In comparison, the acidity values were 4.20% and 3.61% for the oils from seeds roasted at 90 °C and 120 °C. The total phenol result of the control sample was found to be 2.55 mg GAE/g, while the total phenol contents in Chia samples roasted at 90 °C and 120 °C are determined as 2.34 mgGAE/g and 2.14 mg GAE/g, respectively. Also, the flavonoid contents of the roasted chia samples (90 °C and 120 °C) were reported as 13.71 mgCE/g and 12.91 mgCE/g, respectively. It was observed that the application of roasting caused a decrease in quercetin and resveratrol values (p < 0.01). The highest antioxidant value (80.13%) was established in chia sample roasted at 90 °C. Quercetin, catechin, resveratrol, kaempferol and izorhamnetin were the main phenolic components of chia seeds. Other phenolic components such as syringic acid, p-cuoumeric acid, caffeic acid, and gallic acid were found at quite low levels. It was observed that of roasting application caused a decrease in quercetin and resveratrol values. The highest fatty acids in chia seeds were linoleic and linolenic acids. Linolenic and linoleic acid results of chia oils were recorded to be between 64.58 and 68.10% to 17.30 and 18.44%, respectively. The palmitic, stearic, oleic, linoleic and linolenic (except sonication) acid contents of the chia oils obtained by Soxhlet and sonication systems from roasted seeds were found high compared to the control.

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Graphical abstract: The oil content and fatty acid profile distributions of the olives, which give taste and flavor to the olives, must also be monitored before and after fermentation. Research work was carried out to investigate the oil results and fatty acid compositions of the oils obtained from “Ayval?k” and “Gemlik” olives debittered with different solutions and fermented.

The moisture results, bioactive compounds, phenolic and mineral amounts of date fruits showed significant changes depending on package types, storage temperatures and fruit types. The moisture content of date fruits stored at -18 °C was higher than that of date fruits stored at other temperatures (5 and 25 °C). The highest moisture loss in date fruits was observed in fruits stored at 25 °C. The storage temperature with the highest total phenol amounts of the Khalas, Ruzeiz and Sukkari date cultivars was at 25 °C, followed by 5 °C and − 18 °C in decreasing order. The storage temperature and packaging types with the highest total flavonoid content of the “Ruzeiz” date variety were “open cardboard” and “sealed in plastic bag and stored in closed cardboard” at 25 °C. In general, the highest phenolic compounds were detected in “Khalas” date variety, followed by “Ruzeiz” and “Sukkari” varieties in decreasing order. While the most abundant macro element in date varieties was K, followed by P, Mg and Ca, the most abundant micro elements were Fe, and followed by Mn, Zn, B and Cu in decreasing order. The P, K, Ca, Mg, Fe, Zn and B results of the “Khalas” date variety stored at 25 °C were higher than those of the “Khalas” date fruits stored at other temperatures.

While the oil result of pumpkin seeds increased with sprouting, it decreased with roasting. The phenolic and flavonoid results of pumpkin seeds were reported between 24.16 (control) and 215.01 mgGAE/100 g (germinated) to 57.14 (control) and 185.72 mg/100 g (germinated), respectively. Antioxidant capacity values of two different methods (DPPH and ABTS) were defined between 0.77 (control) and 4.34 mmol/kg (germinated) to 0.72 (roasted) and 1.90 mmol/kg (germinated), respectively. The results of the obtained phenolic component amounts showed significant differences depending on the treatments applied to the seeds (p < 0.05). The main dominant phenolic components detected in raw, sprouted and roasted pumpkin seeds were catechin, rutin, 3,4-dihydroxybenzoic acid and gallic acid. In general, phenolic component results of pumpkin seeds increased as a result of germination and roasting compared to control. The oils extracted from pumpkin seeds are rich in linoleic and oleic acids. While oleic acid results of the oils extracted from pumpkin seeds are reported between 31.22 (control) and 32.92% (germinated), linoleic acid results of pumpkin seed oils were recorded between 45.66 (germinated) and 48.81% (control). P and K results of pumpkin seeds were reported between 5938.44 (control) and 6788.28 mg/kg (roasted) to 2598.24 (germinated) and 2838.96 mg/kg (roasted), respectively.

The pH results of the brine was partially decreased during fermentation. Significant changes were not observed in the pH values of the brine from the beginning of the fermentation to the end of Ayvalık and Gemlik olives, where different methods were applied. In general, the salt content of olive brine of both varieties fluctuated depending on the fermentation time. When the total phenol results of the olive fruits were compared with the control, it was determined that there were significant differences between bitterness treatment processes and cultivars. The total flavonoid results of the control samples of “Ayvalık” and “Gemlik” olive varietis were reported as 1553.24 and 1252.38 mg/100 g, respectively. Total flavonoid results of whole fermented olives of both olive cultivars were plotted and found at higher levels than crushed fermented olives. The total carotenoid contents of fermented olives showed significant differences when compared to the control samples. In general, antioxidant activity values of olives that were debittered with brine, normal water and lye applied to both olive fruits were found to be at considerably higher levels than those treated with caustic. The sensory properties of fermented olives, whose bitterness is removed with lye, were highly appreciated.

Graphical abstract: In this study, the effect of different additives (pine honey, flower honey, glucose syrup, citric acid and granulated sugar) into 10% brine and the desired composition properties and product qualities after 40 days of fermentation was investigated. Fermented caper fruits were also subjected to sensory analysis in accordance with their purpose, and the jury determined which of the caper fruits with additional additives was more delicious and high quality.

The peel, pulp and seeds of prickly pear fruits contained 84.3%, 82.98% and 5.78% moisture, respectively. Total carotenoid and total flavonoid contents of prickly pear fruit parts ranged between 0.02 µg/kg (peel) and 1.11 µg/kg (seed) to 14.52 mg per 100 g (pulp) and 68.33 mg per 100 g (seed), respectively. Total phenolic contents and antioxidant activities of prickly pear fruit parts were determined between 41.94 mg GAE per 100 g (seed) and 122.10 mg GAE per 100 g (peel) to 0.87% (pulp) and 1.68% (seed), respectively. In general, prickly pear fruit seed, peel and pulp are very rich in catechin and gallic acid. Gallic acid amounts of prickly pear fruit parts varied between 17.46 (pulp) and 27.70 mg per 100 g (peel). Catechin and rutin trihydrate contents of prickly pear fruit portions were identified between 36.74 (pulp) and 122.87 mg per 100 g (seed) to 1.35 mg per 100 g (peel) and 10.04 mg per 100 g (pulp), respectively. The prickly pear seed oil contained 11.99% palmitic, 3.51% stearic, 20.28% oleic and 62.50% linoleic acids.

The oil yields of almonds were determined to be between 42.6% (bitter almond) and 55.4% (‘Nonpareil’). Antioxidant activity and total phenolic contents (TPC) of almonds varied between 4.80% (‘Texas’) and 85.57% (‘Ferragnes’) to 8.82 (‘Nonpareil’) and 109.79 mg gallic acid equivalent (GAE) per 100 g (‘Ferragnes’), respectively. While oleic acid amounts of almond oils are detected to be between 68.95% (‘Texas’) and 75.16% (‘Ferragnes’), linoleic acid amounts of kernel oils were determined to be between 16.74% (‘Ferraduel’) and 23.24% (‘Texas’). Gallic acid amounts in almond kernels were identified to be between 19.85 (‘Ferragnes’) and 35.12 mg/g (bitter almond). Calcium (Ca) and potassium (K) amounts in almonds were measured at between 3163.65 (bitter almond) and 5438.46 mg/kg (‘Texas’) to 5193.57 mg/kg (bitter almond) and 9720.63 mg/kg (‘Ferragnes’), respectively. Phosphorus amounts in almonds were detected at between 4592.31 (‘Nonpareil’) and 6996.71 mg/kg (‘Ferragnes’). As a result, almond variety had an effect on oil content, bioactive properties, fatty acid profiles, polyphenols and mineral contents.

In this study, changes in protein content, bioactive compounds (total phenol, total flavonoid, total carotenoid), radical scavenging activity, polyphenols and minerals of raw and dehydrated hawthorn fruits were compared. The moisture content of hawthorn fruits was determined to be between 7.17% (microwave) and 69.88% (control). In addition, the crude protein content of fresh and hawthorn fruits dehydrated by both drying methods was between 11.37% (control) and 25.53% (microwave). While the total phenolic content of hawthorn fruits increased during drying treatments, the antioxidant activities of hawthorns decreased. The total phenol and total flavonoid content of hawthorn fruits that were oven dried was measured to be higher than that of hawthorn fruits dried by microwave. The L*values of hawthorn samples ranged from 65.66 (control) to 56.72 (dried in a microwave oven). The heat treatment decreased the L*values of samples. The highest a*value (3.36) was found in the sample dried in a conventional oven, while the lowest a*value (−3.27) was determined in the control sample. The highest phenolic constituent was (+)-catechin in fresh and dehydrated (dried) hawthorn fruits, followed by 1,2-dihydroxybenzene, gallic acid, caffeic acid, and syringic acid. Also, the (+)-catechin and 1,2-dihydroxybenzene content of hawthorn fruits was between 9.57 (control) and 29.9 mg/100 g (microwave) and 5.79 (oven) and 24.41 mg/100 g (microwave), respectively. K, P, Ca, and Mg were measured at the highest levels in fresh and dehydrated hawthorn fruits. The K content of fruits changed between 8443.05 (control) and 10,655.62 mg/kg (microwave).

The effect of several essential oils, plant extracts and packaging materials on oxidative stability of virgin olive oil during different storage times was investigated. The formation of free radicals, changing of color, development of rancid odor and taste are formed as a result of the oxidation of stored oils due to the effect of oxygen and light in the environment depending on the properties of the packaging materials used. As the storage time progressed, viscosity, color, free fatty acid, peroxide and K232values were increased. The highest increase in K270value was found in the first month whereas the value of p-anisidine was found to be maximum in the second and third months of storage. The highest acidity (1.91%) and discoloration were observed in the samples stored in the glass-pet bottle while the highest viscosity (99.80 mPa s), peroxide (12.00 meq O2/kg), K232(0.73) and K270(0.11) values are found in the samples stored in the tin. The highest free fatty acid values of samples stored in glass bottles, PET bottles and tin were detected in olive oils added rosemary. The peroxide values of the samples stored in glass and pet bottles decreased at 1st month and increased as the storage process progressed.

Teff grains are subjected to several treatments, such as cooking and baking, and studies on the impact of thermal treatments such as roasting on the bioactive properties, phenolic compounds, fatty acids, and minerals of teff grains are scarce. The objective of this study was to evaluate the effect of microwave and oven roasting processes on total phenol, antioxidant activity, fatty acid compositions, and phenolic compounds of teff grains. Roasting treatments greatly influenced the biochemical content and bioactive properties of teff grains. Roasting increased oil, carotenoids, total flavonoids, and antioxidant activity of teff grains with the highest values being observed in microwave‐roasted grains, except total flavonoids of soluble fraction which was highest in oven‐roasted grains. It also increased total phenolic of soluble fraction and most phenolic compounds in both soluble and bound fractions with the highest values being found in conventional oven‐roasted grains, except gallic acid, trans‐cinnamic acid, naringenin, and isorhamnetin which were high in control samples. In addition, oven roasting increased palmitic acid, linoleic acid, nickel, and boron, whereas microwave roasting increased the content of stearic acid, calcium, magnesium, sodium, iron, copper, zinc, and lead of teff grains compared to controls. The findings of this study indicate that teff grains are suitable sources of nutrients and bioactive compounds that could be enhanced by roasting. The teff grains have high nutritional value, antioxidants, fatty acids, and phenolic compounds which are improved by roasting treatment and hence probable potential application in functional foods. Studying the effects of processing treatments such as roasting of teff grain will help in promoting the worldwide utilization of this important gluten‐free cereal.

Graphic Abstract: The oil and protein contents, fatty acid compositions, total phenol, antioxidant activity, phenolic compounds and the nutrients of raw and sprouted (germinated) “Sarışeker” and “Balyumru” tigernut tuber flours were investigated.

•Bioactive properties of processed hemp seeds were higher than the control.•The highest caffeic and syringic acids were found in germinated hempseeds.•The fatty acids of boiled seed oil is partially higher than the germinated ones.•Protein amounts of germinated hemp seeds were higher compared to the control.

The objective of the present work was to investigate the influence of locations on bioactive propertiest, phenolic compounds and mineral contents of bee pollens. The oil content of pollen grains changed between 3.50% (Alanya) and 6.85% (Russia-Perm Region). The highest total phenolic content (720 mg/100g) and antioxidant activity values (81.4%) were observed in pollens obtained from the Russia-Perm Region and Alanya districts, respectively. Additionally, the highest carotenoid was found in a pollen sample collected from Karaman (Sarıveliler) (98.6 mg/g). The major phenolic compounds were (+)-catechin (66.75-337.39 mg/100g) and quercetin (61.2-1221.7 mg/100g) in all pollen samples. The pollen samples were observed to be a significant source of potassium (3846-6287 mg/kg), phosphorus (2947-5010 mg/kg), calcium (1022-2424 mg/kg) and sulfur (1744-2397 mg/kg). All of the analysis results were significantly affected by supplying locations. The antioxidant activity values of pollens were found partly similar and varied depending on locations. The content of saturated fatty acid (palmitic) was high (20-30%) in the tested pollen samples but did not exceed the content of linoleic acid.

This study was focused on investigation of phenolic compounds, total phenolic contents and antioxidant activities of some wild onions (Crocus chrysanthus(SDA1), Hyacinthella campanıslata(SDA2), Muscari armaniacum(SDA3), Ornithogalum armeniacum(SDA4), Gagea granatelli(SDA5), Hyacinthella heldreichii(SDA6), Muscari neglectum(SDA7), Ornithogalum lanceolatum(SDA-8). SDA-3 had the maximum total phenolic content, with the range of 88.19 mg/100 g, followed by SDA-1 (82.50 mg/100 g). SDA-1 (29.32%) exhibited the best antioxidant activity, followed by SDA-3 (27.92%). The major phenolic compound of SDA-3, SDA-4, SDA-5, SDA-6 and SDA-8 was (+)-catechin, with the ranges of 35.23, 30.76, 33.72, 44.42 and 50.85 mg/100 g, respectively. The dominant phenolic acid of SDA-1 (86.15 mg/100 g) and SDA-7 (22.07 mg/100 g) was determined as gallic acid. Additionally, SDA-2 contained the highest content of isorhamnetin (53.87 mg/100 g). Results indicate that the bulbs of studied plants are potential sources of phenolic compounds and their methanolic extracts have antioxidant activity.

In this study, the effect of microwave and conventional drying on antioxidant activity, phenolic compounds, mineral and total phenolic contents of date fruit meat (Silifke and Anamur) were determined. Both microwave (360, 540 and 720 W) and conventional (70, 90 and 110 °C) drying caused the reduction of phenolic compounds although there can not considerably variation in antioxidant activity of date flesh. Total phenolic contents of date flesh changed between 114.640 mgGAE/100 g (Silifke 540 W) and 133.484 mg GAE/100 g (Silifke 720 W) compared with control sample (156.128 mg GAE/100 g). While P contents of date fruit change between 86.00 mg/Kg (control) and 704.420 mg/Kg (360 W), P contents of Anamur samples ranged from 79.430 mg/Kg (Control) to 1288.780 mg/Kg (360 W). Mineral contents of date fruits dried in microwave oven were found higher than those of observed in conventional dried fruits (especially Ca and Mg contents of date fruits).

The protein amounts of chia seeds were determined between 27.56% (control) and 28.37% (boiled). Total phenolic and antioxidant activity values of chia seeds treated by several applications changed between 237.70 mgGAE/100g (germinated) and 535 mgGAE/100g (roasted) to 15.27 mmol/kg (roasted) and 15.50 mmol/kg (germinated), respectively. While (+)-catechin amounts of seeds are determined between 15.47 (control) and 60.95 mg/100g (roasted), rutintrihydrate contents of seed extracts were identified between 3.98 mg/100g (control) and 24.92 mg/100g(roasted). While linolenic acid values of oils vary between 62.89% (germinated) and 66.76% (rpasted), linoleic acid amounts of oil samples were identified between 18.55% (control) and 21.04% (roasted). While P contents of chia seeds change between 6103.58 mg/kg(boiled) and 7253.45 mg/kg (control), K amounts of seeds varied between 2534.48 mg/kg (germinated) and 5351.58 mg/kg(roasted). In general, it was observed that the mineral content of boiled chia seeds was low compared to the control and other treated seeds.