Encapsulation of bioactive compounds extracted from Cucurbita moschata pumpkin waste: the multi-objective optimisation study.

AIM: Artificial neural network (ANN) development to find optimal carriers (pea protein-P, maltodextrin-M, and inulin-I) mixture for encapsulation of pumpkin waste bioactive (ß-carotene and phenolics). METHODS: Freeze-drying encapsulation and encapsulates characterisation in terms of bioactive contents and encapsulation efficiencies, water activity, hygroscopicity, densities, flowability, cohesiveness, particle size (laser diffraction), solubility, colour (CIELab), morphological (SEM), stability and release properties. RESULTS: Optimal encapsulates, OE-T (with highest total bioactive contents; P, M, and I of 53.9, 46.1, and 0%w/w) and OE-EE (with highest bioactive encapsulation efficiencies; P, M, and I of 45.5, 32.0, and 22.5%w/w) had particle diameters of 94.561 ± 1.341 µm and 90.206 ± 0.571 µm, the span of 1.777 ± 0.094 and 1.588 ± 0.089, highest release at pH 7.4 of phenolics of 71.03%w/w after 72 h and 66.22%w/w after 48 h, and ß-carotene of 43.67%w/w after 8 h and 48.62%w/w after 6 h, respectively. CONCLUSION: ANN model for prediction of encapsulates' preparation, showed good anticipation properties (with gained determination coefficients of 1.000).

Encapsulation and Degradation Kinetics of Bioactive Compounds from Sweet Potato Peel During Storage.

RESEARCH BACKGROUND: The aim of this work is to evaluate utilization of sweet potato peel as a source of bioactive compounds. The effect of solvents (acetone and acetone/ethanol mixture) on the extraction efficiency of total carotenoids and phenolics from sweet potato tuber, flesh and peel, and antioxidant activity were investigated. Sweet potato peel extract stood out in terms of antioxidant activity and was chosen for encapsulation by spray and freeze-drying. EXPERIMENTAL APPROACH: Encapsulation is an effective method to improve phytochemical stability by entrapping the core material with a coating agent. In this study, spray and freeze-drying techniques were applied for improving the stability of bioactive compounds (carotenoids and phenolics) using whey protein as a coating material. The main advantages of the applied techniques over the other encapsulation techniques are simplicity, continuity, effectiveness, availability and applicability. RESULTS AND CONCLUSIONS: Physicochemical characteristics revealed that spray drying resulted in the formation of lower size particles, better flow properties and encapsulation efficiency of carotenoids. The retention of encapsulated and non-encapsulated bioactive compounds was monitored during storage in daylight and dark conditions. Storage conditions affected the carotenoid retention, whereas higher degradation rate of all samples was observable in daylight. Phenolic compounds exhibited higher retention in all investigated samples. Degradation kinetic parameters suggest the longer shelf life of spray dried encapsulated extract and potent method for stabilization of bioactive ingredients. NOVELTY AND SCIENTIFIC CONTRIBUTION: This study demonstrates that the spray drying technique and utilization of sweet potato peel have a big potential for the development of functional additives with improved nutritional, colour and bioactive properties.

Application of encapsulated natural bioactive compounds from red pepper waste in yogurt.

Aim: The aim of this study was to encapsulate red pepper waste (RPW) bioactives and monitor their stability in yogurt.Methods: RPW extract was encapsulated in whey protein using spray and freeze-drying techniques. Physicochemical characteristics of encapsulates were evaluated, and better encapsulates were used to develop functional yogurt. Retention of bioactives was followed over 21 days of storage, and sensory analyses were assessed.Results: Freeze-dried encapsulates (FDE) showed better characteristics like water activity, moisture content, solubility, flowing and colour properties, and, therefore, incorporated in yogurt. Yogurt with FDE successfully retained carotenoids (71.43%) and caused increasing of polyphenol retention (up to 123.73%). This yogurt exhibited higher sensory and general acceptability scores compared to control sample. The fortification of yogurts had a positive influence on maintaining the initial number of lactic acid bacteria during storage.Conclusion: Freeze drying and utilisation of pepper waste are efficient for functional food development, with improved nutritional, colour and bioactive properties.

Encapsulation of Beetroot Pomace Extract: RSM Optimization, Storage and Gastrointestinal Stability.

One of the great problems in food production are surplus by-products, usually utilized for feeding animals and for preparation of dietary fibre or biofuel. These products represent potential sources of bioactive antioxidants and colour-giving compounds which could be used in the pharmaceutical industry and as food additives. In the present study beetroot pomace extract was encapsulated in soy protein by a freeze drying method. Process parameters (core: wall ratio, extract concentration and mixing time) were optimized using response surface methodology (RSM) in order to obtain the optimum encapsulate (OE) with the highest polyphenol encapsulation efficiency (EE) and radical scavenging activity on DPPH radicals (SA). Using the calculated optimum conditions, the EE (86.14%) and SA (1668.37 µmol Trolox equivalents/100 g) of OE did not differ significantly (p < 0.05) from the predicted ones. The contents of total polyphenols (326.51 mg GAE/100 g), flavonoids (10.23 mg RE/100 g), and betalains (60.52 mg betanin/100 g and 61.33 mg vulgaxanthin-I/100 g), individual content of phenolic compounds and betalains by HPLC, and the ability to reduce Fe(3+) ions, i.e., reducing power (394.95 µmol Trolox equivalents/100 g) of OE were determined as well. During three months of storage at room temperature, polyphenol retention was much higher (76.67%) than for betalain pigments, betacyanins (17.77%) and betaxanthins (17.72%). In vitro digestion and release of phenolics from OE showed higher release rate in simulated intestinal fluid than in gastric fluid. These results suggest encapsulation as a contemporary method for valorisation of sensitive bioactive compounds from food industry by-products.

Sour cherry pomace extract encapsulated in whey and soy proteins: Incorporation in cookies.

One of the potential sources of valuable bioactives is pomace, a by-product from fruit juice processing industry. In the presented study, bioactive compounds extracted from cherry pomace, encapsulated in whey and soy proteins, have been incorporated in cookies, replacing 10% (WE10 and SE10) and 15% (WE15 and SE15) of flour. Total polyphenols, anthocyanins, antioxidant activity and colour characteristics of enriched cookies were followed during 4 months of storage. Total polyphenols of WE10, SE10, WE15 and SE15 have shown a slight increase (23.47, 42.00, 4.12 and 1.16%, respectively), while total anthocyanins (67.92, 64.33, 58.75 and 35.91%, respectively) and antioxidant activity (9.31, 24.30, 11.41 and 12.98%, respectively) decreased. Colour parameters (L(∗), a(∗) and b(∗)) of cookies were influenced by the colour of encapsulates. Fortified cookies received satisfactory sensory acceptance as well. Encapsulated sour cherry pomace bioactives have positively influenced functional characteristics of fortified cookies and their preservation.

Anthocyanin profiles and biological properties of caneberry (Rubus spp.) press residues.

BACKGROUND: The global interest in natural food colours shows increasing attention towards new product development to replace synthetic colourants, because of the strengthening of legislative rules and consumer awareness of synthetic additives and chemicals in food. This study was designed to evaluate anthocyanin content and biological activities of press residues from four caneberries: two raspberry (Rubus idaeus, cv. 'Meeker' (RM) and 'Willamette' (RW)) and two blackberry (Rubus fruticosus, cv. 'Thornfree' (BT) and 'Cacanska bestrna' (BC)) cultivars. RESULTS: Analysis by high-performance liquid chromatography-diode array detection-electrospray ionization-tandem mass spectrometry identified cyanidin glycosides in all press residues, cyanidin 3-glucoside being prevalent in BC (1360.6 mg kg(-1)) and BT (1397.7 mg kg(-1)), and cyanidin 3-sophoroside in RM (349.2 mg kg(-1) ) and RW (581.0 mg kg(-1)). Antioxidant capacity (AC), evaluated by ABTS (2,2'-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) assay, reducing power (RP) and α-glucosidase inhibitory potential (α-GIP) was higher in blackberry press residues. Total anthocyanin content was in good correlation with AC (r = 0.953; P < 0.05), RP (r = 0.993, P < 0.01) and α-GIP (r = 0.852, P < 0.15). CONCLUSION: This study has revealed the potential for valorization of juice production byproducts for further industrial use as a rich source of bioactive compounds and natural colourants (mainly anthocyanins). Also, they can provide health-promoting effects beyond their general organoleptic acceptance in food product development.