Physicochemical and antioxidant properties of the pequi (Caryocar brasiliense Camb.) almond oil obtained by handmade and cold-pressed processes.

Abstract: The aim of this study is to characterize physical and chemically and determine the antioxidant capacity of pequi almond oils (PAO) extracted by handmade and by cold-pressing. Both oils showed good quality by acid, peroxide and thiobarbituric acid values. The fatty acid (FA) profile showed a significant presence of monounsaturated FA, mainly oleic acid (53.48 to 55.41%); saturated FA, such as palmitic acid (33.30 to 35.89 %); and polyunsaturated FA (PUFA), such as linoleic acid (5.85 to 7.23%). The total phenolic (TP) and carotenoid content ranged in concentration from 87.56 to 392.00 mg GAE/100 g and 36.03 to 262.40 mg/100 g, respectively. The tocopherol and phytosterol results indicated the predominant presence of α-tocopherol (52 to 67%) and stigmasterol (63 to 68 %). The antioxidant capacity of PAO as measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH?) method oscillated from 58.48 mg/mL to 76.46 mg/mL (IC50), from 10.61 to 40.46 µmol TE/g by the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS?+) method, and from 113.93 to 280.85 µmol TE/100 g and 164.49 to 277.86 µmol TE/100 g, by the lipophilic and hydrophilic oxygen radical absorbance capacity (ORAC) methods, respectively. The oils presented a good oxidative and thermal stability by Rancimat method (IP of 7.33 a 15.91 h) and curves thermogravimetric and differential scanning calorimetry (To 337-363 °C and 159-184 °C, respectively). The results confirmed the presence of compounds that conferred antioxidant capacity and oxidative and thermal resistance for PAO made by handmade or cold-pressing, indicating that these oils can potentially be used for food and non-food applications.

Physiological stress responses in the warm-water fish matrinxã (Brycon amazonicus) subjected to a sudden cold shock.

Respostas fisiológicas ao estresse do peixe de águas tépidas matrinxã (Brycon amazonicus) submetido à queda brusca de temperatura.

Maturity index and cold storage effects on postharvest quality of 'Packham's Triumph' and 'Rocha' pears.

Pears have been grown in the south region of Brazil, where the climatic conditions are favourable. The aim of this work was to determine the harvest maturity index as well as maximum storage period of 'Packham's Triumph? and 'Rocha' pears to maintain quality attributes. The ?Packham?s Triumph? fruit were harvested from a commercial orchard at 7 days intervals and flesh firmness was used as a maturity index (MI1=76, MI2=67 and MI3=58 N). ?Rocha? pears were harvested twice and they were considered as MI1 and MI3 because of the firmness values. The fruit were stored at 1±1C and 90-95% RH for 15, 30, 45 and 60 days and evaluated at the end of each storage period and after five days at room temperature (24±1C), simulating a helflife period. Flesh firmness, water loss, peduncle dehydration, epidermis colour, soluble solids, titratable acidity were measured. ?Packham?s? pears harvested at MI1 and MI2 showed firmness loss after 30 days of cold storage, whereas fruit harvested at MI3 retained the initial values, resulting in firmer fruit after 60 days (P<0.001). Fruit harvested in MI3 had less firmness loss after 5 days at room temperature following 45 and 60 days of cold storage. ?Rocha? pears harvested in MI1 and MI3 showed firmness reduction during cold storage, which was intensified at room temperature. Maximum values of water loss approached 6%. Fruit peduncles of both cultivars dehydrated after 60 days of cold storage, but their colour remained green, independent of harvest maturity index. ?Packham?s Triumph? and ?Rocha? pears harvested at MI3 showed better quality attributes after 60 days of cold storage plus 5 days of shelf-life than fruit harvested at other maturity stages.