Optimization of complex coacervation parameters for the production of encapsulated black garlic using response surface methodology.

The purpose of this study was to optimize black garlic encapsulation parameters (core/coating ratio, extract concentration, and coacervate/maltodextrin [MD] ratio) using central composite design of the response surface methodology based on encapsulation efficiency (EE) (%). The optimum parameters were determined as 4.0 for the coating material/core ratio, 50% for the extract concentration, and 6.0 for the MD/coacervate ratio depending on the EE (%). The antioxidant activity values were determined as 101 and 134 µmol Trolox/100 g dry weight (DW) for the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) methods, respectively, whereas the total phenolic content was 49 mg gallic acid equivalent/100 g DW for the encapsulated black garlic samples. S-Allyl-l-cysteine (SAC), γ-l-glutamyl-SAC (GSAC), γ-l-glutamyl-(S)-trans-1-propenyl-l-cysteine, and allicin were the organosulfur (OS) compounds determined in the samples. The SAC concentration of the encapsulated black garlic samples was determined as 22.36 mg/g, whereas the GSAC content was found at a lower concentration (0.33 mg/g) compared to SAC. The allicin content was quantified to be 0.31 mg/g. The encapsulated samples were also characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. The FT-IR analysis revealed specific functional groups, including hydroxyl, carbonyl, and glycosidic linkage. The interaction between lentil protein isolate and pectin was strong enough to encourage capsule formation as visualized in the SEM images. This study shows the potential of black garlic coacervates as a functional ingredient for the food industry due to their stability, solubility, and preservation of OS and antioxidant compounds.

FTIR spectroscopy for prediction of quality parameters and antimicrobial activity of commercial vinegars with chemometrics.

BACKGROUND: The aim of this study was to discriminate between commercial apple, rice, balsamic, red-wine, rose, white-wine, grape, and pomegranate vinegars according to their antimicrobial activities, total phenolic contents (TPC), antioxidant activities, and color parameters, and to predict the quality characteristics of vinegars using Fourier transform infrared (FTIR) spectroscopy. RESULTS: Results showed that the highest TPC (3971.43 ± 25.00) was found in balsamic vinegar whereas the lowest TPC was observed in rice vinegar (14.36 ± 0.16). Antioxidant activities of vinegars were correlated with TPC. Grape-based vinegars exhibited higher antimicrobial activity against Staphylococcus aureus (S. aureus), Escherichia coli (E.coli) and Pseudomonas aeruginosa (P.aeruginosa). However, there were no statistically significant differences among vinegars in terms of antimicrobial activities. According to principal component analysis (PCA) and hierarchical cluster analysis (HCA), vinegars were classified into three groups and each group consisted of vinegars from different raw materials. Prediction models were constructed successfully using partial least squares (PLS) considering whole FTIR spectral data. CONCLUSION: The results indicated that FTIR could be used as a rapid method to estimate the antimicrobial activities, TPC, color and antioxidant activities of vinegars. © 2018 Society of Chemical Industry.