Development of an Optimized Method to Obtain a Limonene-Rich Concentrate from the Discarded Lemon Peels.

In this study, lemon peels were used as volatile component source. Automatic solvent extraction has been used for the recovery of limonene rich citrus volatile extract for the first time. The process parameters (amount of raw material, immersion time and washing time) were analyzed to optimize the process by means of Box-Behnken design via response surface methodology. The optimum conditions were achieved by ~10 g fresh lemon peel, and ~15 min immersion time and ~13 min washing time. The difference between the actual (89.37 mg/g limonene) and predicted (90.85 mg/g limonene) results was satisfactory (<2 %). α-Terpinene, ß-pinene, citral, É£-terpinene and linalool were determined as other major volatiles in the peel extract. FT-IR and 1 H- and 13 C-NMR spectroscopies were applied to verify the identified volatile compounds.

Preservation of active components in olive leaf extract by spray drying method in biodegradable polymers: Optimization, in vitro gastrointestinal digestion and application.

INTRODUCTION: Encapsulation of the bioactive ingredients in biodegradable and edible polymers is an alternative novel application method to keep these kind of natural products stable. OBJECTIVE: The purpose is to optimize the encapsulation system of olive leaf extract by spray drying method, and to apply the products into a model food. METHODS: Olive leaf extract was encapsulated in arabic gum/maltodextrin blend by spray drying method. Combined design approach under I-optimal design type was used to optimize the system. Characterisation studies under moisture content, water activity, solubility, bulk density, tapped density, Carr index, particle size distribution, powder morphology and glass transition temperature were applied to the microparticles obtained under optimum conditions. The bioavailability of the encapsulated active material was tested by in vitro gastrointestinal digestion. Furthermore, microparticles produced under optimum conditions were also evaluated for a potential functional food application. RESULTS: The optimum conditions were achieved by arabic gum/maltodextrin (3.7:6.3) with 10% (w/v) in the mixture of wall material and active material under 165.5°C to achieve maximum encapsulation efficiency (86.92%), encapsulation yield (71.32%) and antioxidant activity (5.74 mg Trolox equivalent antioxidant capacity/g dry microparticle). CONCLUSIONS: Olive leaf extract encapsulated in arabic gum/maltodextrin may be a good alternative additive to prevent the lipid oxidation in fat-containing food products as well as improvement of the product quality by functional properties.

Highly clean recovery of natural antioxidants from lemon peels: Lactic acid-based automatic solvent extraction.

INTRODUCTION: Food industry generates large amounts of waste by-products rich in natural antioxidants. On the other hand, application of advanced processes for the recovery of these fine chemicals is another popular topic of recent years. OBJECTIVE: The purpose of this study is to propose a green extraction method by application of deep eutectic solvent-based automated solvent extraction (AMSE) from lemon peels. METHODS: The primary polyphenols (hesperidin, naringin, and p-coumaric acid) and the total polyphenols of the lemon peel extract were quantified and used as response for the optimisation of the AMSE conditions. The Box-Behnken design type of the response surface method (RSM) was chosen for optimisation study. Scavenging activity of the lemon peel extract against 2,2-diphenyl-1-picrylhydrazil (DPPH) free radical was also measured in vitro. RESULTS: The optimum conditions for the highest total phenolic (7.47 mg-gallic acid equivalent [GAE]/g-lemon peel [LP]), naringin (5.05 mg/g-LP), p-coumaric acid (3.27 mg/g-LP), and hesperidin (0.07 mg/g-LP) yields were obtained by 1.5 h of extraction time, 46% water (v/v), and 5 g of peel. The antioxidant activity changed between 37.31% and 94.10% in the peels. CONCLUSIONS: Extraction time was the most effective process factor for the total phenolic and p-coumaric acid yields, while water addition was statistically very important (p < 0.0001) for the naringin and hesperidin yields in the current AMSE system. The second-order models generated for the selected systems represent the data satisfyingly based on the high coefficients of determination (> 0.99), statistically significant p-values (<0.0001), coefficient of variation values (< 10%), and non-significant lack-of-fit values (p > 0.05).

Development of an Encapsulation Method for Trapping the Active Materials from Sour Cherry Biowaste in Alginate Microcapsules.

This study aims to contribute to those valorization approaches for the recovery process of high-value-added substances in environmentally friendly ways. In this study, one of the most consumed juice products was selected for providing waste byproducts (peel). Sour cherry peels were subjected to automatic solvent extraction using a GRAS solvent (aqueous 80% ethanol, v/v). Then, encapsulation for the preservation of the related extract was performed by ionic gelation in alginate beads. The process conditions (gelling medium concentration, wall material concentration, and hardening time) were optimized by a Box-Behnken design (statistical experimental design approach). An almost 80% encapsulation efficiency was achieved under the proposed method (7.8% CaCI2, 1.3% alginate, and 26 min). The inhibition effect of the produced capsules against DPPH (2,2-diphenyl-1-picrylhydrazil) radicals also shows that the current products might represent potential alternative natural antioxidants for food formulations. The morphological properties were also measured.