scholarly journals The Study of Thermal Properties of Blackberry, Chokeberry and Raspberry Seeds and Oils

2021 ◽  
Vol 11 (16) ◽  
pp. 7704
Author(s):  
Iga Piasecka ◽  
Agata Górska ◽  
Ewa Ostrowska-Ligęza ◽  
Stanisław Kalisz
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Polyunsaturated Fatty Acids ◽  
Seed Oil ◽  
Seed Oils ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Soxhlet Apparatus ◽  
Melting Fraction

The seeds of berry fruits are a component of fruit waste occurring in the production process. Circular economy rules focus on decreasing the amount of waste produced and reusing by-products when it is possible. To determine the possible applications of the studied fruit industry wastes, the thermal properties of berry seeds and of oil extracted from the tested material were examined. Differential scanning calorimetry (DSC), modulated differential scanning calorimetry (MDSC), and thermogravimetry (TG) of blackberry, chokeberry, and raspberry seeds were carried out. The properties of oil extracted in the Soxhlet apparatus were studied by pressure differential scanning calorimetry (PDSC), TG, and gas chromatography (GC) measurements. The results show that berry seeds lipids are from different melting fraction groups with a dominance of low-melting fraction, which consists of mono- and polyunsaturated fatty acids. There are also occurring residues of carbohydrates and inorganic, thermostable substances in the studied seeds. A GC analysis of oil confirms that the polyunsaturated fatty acids (PUFA) are most abundant and amount to 78.72 ± 0.06% in blackberry seed oil, 73.79 ± 0.14% in chokeberry seed oil, and 82.74 ± 0.03% in raspberry seed oil. The PDSC study showed that the most oxidative stable oil is blackberry seed oil, followed by raspberry and chokeberry seed oils. According to the obtained results, berry seeds can be used as a source of oil in food or other production chains. However, more detailed characteristics of berry seed oils are needed to determine their applicability.

scholarly journals Thermal and Kinetic Properties of Brazilian Coffea Arabica Beans

2021 ◽  
Vol 11 (14) ◽  
pp. 6324
Author(s):  
Rita Brzezińska ◽  
Agata Górska ◽  
Magdalena Wirkowska-Wojdyła ◽  
Ewa Ostrowska-Ligęza ◽  
Joanna Bryś
Keyword(s):  
Fatty Acids ◽  
Differential Scanning Calorimetry ◽  
Thermal Behaviour ◽  
Kinetic Properties ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Fatty Acids Profile ◽  
Coffee Beans ◽  
Roasting Process ◽  
Tg And Dtg

The chemical composition of green coffee beans depends on the number of parameters, such as coffee cherry processing methods, used. The quality of roasted coffee is related to the certain substances that developed during the roasting process and that are responsible for the organoleptic properties. The main objective of this study was an investigation of the thermal behaviour and the fatty acids profile of green and roasted Brazilian Santos coffee beans. The glass transition temperature was measured using modulated differential scanning calorimetry (MDSC). The thermal behaviour of coffee samples was evaluated by means of thermogravimetry (TG) and first derivative thermogravimetry (DTG). The oxidative stability and kinetic parameters were characterized with the use of differential scanning calorimetry (DSC). According to the TG and DTG curves, coffee samples showed different behaviour of thermal degradation in the atmosphere of oxygen and nitrogen. Our research shows that the thermal properties and fatty acids profile did not change during the roasting process.

scholarly journals COMPARATIVE STUDY OF THE BIOLOGICAL VALUE AND OXIDATIVE STABILITY OF WALNUT AND PUMPKIN-SEED OILS

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
T. Nosenko ◽  
T. Koroluk ◽  
S. Usatuk ◽  
G. Vovk ◽  
T. Kostinova
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Seed Oil ◽  
Oxidation Stability ◽  
Monounsaturated Fatty Acids ◽  
Seed Oils ◽  
Oil Oxidation ◽  
Pumpkin Seed ◽  
Walnut Oil ◽  
Pumpkin Seed Oil

The work is devoted to the study of the biologically active components and the oxidation stability of oils made from non-traditional raw materials such as walnuts and pumpkin seeds. The characteristics that have been determined are the content of phospholipids, carotenoids, chlorophylls, tocopherols, and sterols, the composition of fatty acids and tocopherol homologues, the acidity and oxidation stability of walnut and pumpkin-seed oils. Walnut and pumpkin-seed oils contain a significant amount of polyunsaturated fatty acids, in particular, walnut oil contains linolenic acid and has the ratio ω-3:ω-6 of polyunsaturated fatty acids, which is close to the recommended ratio. The linoleic (polyunsaturated, ω-6) and oleic (monounsaturated) fatty acids dominated in the fatty acid composition of pumpkin-seed oil, and the sum of saturated fatty acids was three times as high as that in walnut oil. An important property of walnut oil is a very high ratio of ω-3:ω-6 polyunsaturated fatty acids, 1:5, which is almost what is recommended by dietitians for the human diet. The difference in the total tocopherol content of the two oil samples was slight, but the composition of tocopherol homologues was very distinctive, i. e. β-tocopherol was the main homo;ogue in the walnut oil and α-tocopherol in the pumpkin-seed oil, respectively. The acidity of the oil samples increased quite rapidly, reaching the value close to 4 mg KOH/g of in 63 days for walnut oil, and in 70 days for pumpkin-seed oil. The oxidative stability of the two oil samples was estimated by changes of the peroxide value during 98 days of oil storage. It has been shown that the induction period of walnut oil oxidation, defined as the start of an increase of the peroxide index, was 56 days, in spite of a high content of polyunsaturated fatty acids, particularly, linolenic acid. The duration of the induction period of pumpkin-seed oil oxidation and the shelf life of this oil were 70 and 98 days, respectively, while the shelf life of walnut oil was about 90 days. The higher resistance of pumpkin-seed oil to oxidative damage is primarily due to the fatty acid composition of this oil, namely to a high content of saturated and monounsaturated fatty acids and almost twice as low a content of polyunsaturated fatty acids compared to that of walnut oil. Both oils can be recommended as a valuable source of polyunsaturated fatty acids, antioxidants, and vitamins for human nutrition.

scholarly journals Improved Processing and Properties for Polyphenylene Oxide Modified by Diallyl Orthophthalate Prepolymer

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2016
Author(s):  
Honghua Wang ◽  
Qilin Mei ◽  
Yujie Ding ◽  
Zhixiong Huang ◽  
Minxian Shi
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Phase Separation ◽  
Dilution Effect ◽  
Gradual Decrease ◽  
Gel Point ◽  
Dynamic Mode ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Polyphenylene Oxide

Diallyl orthophthalate (DAOP) prepolymer was investigated as a reactive plasticizer to improve the processability of thermoplastics. The rheology of blends of DAOP prepolymer initiated by 2,3-dimethyl-2,3-diphenylbutane (DMDPB) and polyphenylene oxide (PPO) was monitored during the curing process, and their thermal properties and morphology in separated phases were also studied. Differential scanning calorimetry (DSC) results showed that the cure degree of the reactively plasticized DAOP prepolymer was reduced with increasing PPO due to the dilution effect. The increasing amount of the DAOP prepolymer led to a gradual decrease in the viscosity of the blends and the rheology behavior was consistent with the chemical gelation of DAOP prepolymer in blends. This indicated that the addition of the DAOP prepolymer effectively improved processability. The phase separation occurring during curing of the blend and the transition from the static to dynamic mode significantly influences the development of the morphology of the blend corresponding to limited evolution of the conversion around the gel point.

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