Bio-antioxidants Activity: Their Mechanisms and Measurement Methods

Bioactive food components (such as phenolic compounds, carotenoids, anthocyanins, tochopherols, ascorbic acid, flavonoids, minerals, enzymes and pectin) are active ingredients in food or dietary supplements, which proven to have an important role in health, and are safe for human consumption. These compounds exert their antioxidant effects by different mechanisms such as single electron transfer or hydrogen atom transfer, and their efficiencies can be evaluated by several methods such as ferric reducing ability of plasma, oxygen radical absorbance capacity assay, total radical trapping antioxidant parameter, total oxidant scavenging capacity, conjugated dienes, lipoxygenase activity inhibition assay, chemiluminescence, deoxyribose, tocopheroxyl radical attenuating ability, and nitric oxide radicals trapping. In this review, these mechanisms and methods will be discussed in details

Encapsulation of Barberry Fruit Extracts by Spray Drying and Liposome Entrapment

Barberry is a native Iranian plant including species Berberis integerrima and B. vulgaris. Barberry fruit is used for preparing sauces, jellies, carbonated drinks, candies, food colour powders, jams, marmalades, chocolates, juices, and nectars. They are used as a natural food colorant rich in anthocyanins instead of harmful artificial ones. They contain polyphenols and antioxidants that reduce damage from free radicals and prevent chronic diseases and cancers. Barberry fruit extracts were encapsulated in maltodextrin by spray drying and liposome entrapment. The sizes of spray dried particles were reported 1–20 μm by SEM. Dimensions of empty and extract loaded liposomes (B. vulgaris and B. integerrima) were 18–28, 37–51, and 51–77 nm, respectively, by FE-SEM. The moist diameter of liposomes measured by dynamic light scattering (DLS) method at day 0 and after 6 months at –18 °C were as follows; empty liposomes: 163.9±2.23 and 378.90±4.98, liposomes loaded with extracts: 135.2±2.04 and 160.90±2.19 (B. vulgaris) and 113.4±1.83 and 144.20±2.01 nm (B. integerrima). Evaluation of thermal-oxidative decomposition from differential scanning calorimetry (DSC) results at 0–45–90 days showed that the antioxidant activity and the onset temperature of the encapsulated extract was higher than the control. The extracts encapsulated in liposomes, especially B. integerrima extract, had better antioxidant properties

Gamma irradiation effects on microbial and qualitative properties of rosehip (Rosa canina L.) fresh fruit during storage

Abstract Fruit of rosehip ( Rosa canina L.) has high economic, medicinal, and nutritional values. Rosehip is rarely consumed fresh due to limitations of seasonality and short shelf life. They are usually processed, which affects the nutritional and sensory characteristics of rosehip products. Radiation processing along with storage at 4 °C is a way to increase safety and prolong fresh rosehip durability. Rosehip fruits were harvested at enough maturity stage, irradiated at doses of 0 (control), 0.5, 1, and 1.5 kGy, and stored at 25 and 4 °C for 60 days. Gamma irradiation at 1 kGy caused an increase in weight loss during storage for 60 days at 25 °C. Microbial counts, total phenolic contents (TPC), total anthocyanin contents (TAC), ascorbic acid contents (AAC), DPPH • scavenging activity, total colour difference ( ∆E h ), and sensory properties were acceptable in the sample irradiated at 1 kGy and preserved for 60 days at 4 °C. The amounts of acidity, pH, and total soluble solids (TSS) were not significantly different from the control. Gamma irradiation at 1 kGy and thereafter storage of the irradiated fruit at 4 °C are suggested as minimal processing and storage conditions of rosehip fresh fruit (RFF) for 60 days