Physicochemical and sensory properties of biscuits formulated with Tenebrio molitor and Alphitobius diaperinus flours.

The use of insects is considered by Food and Agriculture Organization (FAO) as an alternative source of protein for human and animal food in order to reduce the carbon footprint caused by meat production and to supply the expected population increase with food. In this regard, the aim of this study was to analyze the physicochemical aspects (water activity, protein and fat content, size, optical and mechanical properties) of biscuits prepared with two different insect powders (Tenebrio molitor [TM] and Alphitobius diaperinus [AD], in different percentages [0, 13, 17, 20, and 25%]) based on total weight. In addition, the biscuits formulated with the highest insect powder content were subjected to sensory analysis. The results revealed that all the biscuits formulated with insect powders may be labeled as "high in protein" products following Regulation (EC) No. 1924/2006, although they were not as thick as the control biscuits. The L* and b* coordinates were significantly lower when the insect powders were included, which implied a darkening of the biscuits, which were also harder than the control biscuits, regardless the concentration used. According to the sensory analysis, most panelists perceived the biscuits containing insects as too dark and not crunchy enough and an increase in sweetness might improve their acceptability. Finally, further studies should be carried out to analyze the influence of different structural components and flavorings, such as chocolate, in the formulation of biscuits with insect powders to improve their sensory attributes.

Antioxidant and anti-inflammatory activities of freeze-dried grapefruit phenolics as affected by gum arabic and bamboo fibre addition and microwave pretreatment.

BACKGROUND: Recent epidemiological studies have suggested that phenolic compounds present in grapefruit play an important role in the bioactive properties of this fruit. However, the consumption of fresh grapefruit is low. Freeze-dried powdered grapefruit can be an alternative to promote this fruit consumption. To improve the quality and stability of the powdered fruit, encapsulating and anticaking agents can be added. In the present study, different grapefruit powders obtained by freeze-drying with the addition of gum arabic (1.27 g per 100 g) and bamboo fibre (0.76 g per 100 g) with and without a pre-drying microwave treatment were compared with the fresh and freeze-dried fruit with no carriers added, aiming to evaluate the effect of these preservation processes on phenolics content and on its antioxidant [1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing ability of plasma (FRAP)] and anti-inflamatory (evaluated in RAW 264.7 macrophages) capacities. RESULTS: Freeze-drying and gum arabic and bamboo fibre addition significantly increased total phenolics, as well as the antioxidant and anti-inflammatory activities (by inhibiting nitric oxide production of lipopolysaccharide activated RAW 264.7 macrophages), of grapefruit. An additional increase in these parameters was obtained with microwave pretreatment before freeze-drying. CONCLUSIONS: The combined addition of gum arabic and bamboo fibre to grapefruit puree and the application of a microwave pretreatment improve the functional properties of the fruit without showing cytotoxicity in vitro. © 2017 Society of Chemical Industry.