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    Item type:Publication,
    Probiotic encapsulation by spray drying using konjac glucomannan hydrolysate as wall material and its application in ice cream
    (2018-01-01)
    Yanprapasiri, K.
    ;
    Lohsrithong, C.
    ;
    Setthachaimongkol, S.
    ;
    Mekkerdchoo, O.
    ;
    Borompichaichartkul, C.
    This research aims to study encapsulation efficiency of cell probiotics by using Konjac glucomannan hydrolysate (KGMH) under spray drying. KGMH was prepared from Konjac glucomannan solution (KGMS) at different concentrations. Lactobacillus casei was used in this study as it is commonly used in food industry and resistance to heat. The effect of wall material (HGMH) concentration on encapsulation efficiency of the cell probiotic was evaluated. Probiotics culture was prepared by inoculating in sterile MRS broth and incubated at 37°C for 48 hours, the cells were harvested in the early stationary phase. Konjac glucomannan solution was hydrolysed by mannanase at 40°C for 4 hours. Then, probiotic solution (10 log CFU/ml) was mixed with KGMH at concentration of 15%, 20% and 25% (w/w). Spray drying condition was kept at constant inlet air temperature of 170°C, outlet air temperature of 85°C and feed flow rate of 10 mL min-l. Encapsulated probiotic with KGMH at concentration of 25% (w/w) exhibited the highest encapsulation efficiency (95.4 %), water activity of 0.198 and moisture content of 4.38 % (w.b.). For application in ice cream, microcapsules of probiotic encapsulated with KGMH at concentration of 25% with and without 10% (w/w) trehalose were then mixed into milk ice cream separately. The ice cream was stored at -18°C for one month. The survival rate of microencapsulated probiotic cells and free cells probiotics in the ice cream were measured. It was found that microcapsule of KGMH at concentration of 25% (w/w) with 10% (w/w) trehalose gave higher survival rate of probiotics cell (> 90%) in ice cream under freezing temperature than KGMH at concentration of 25% (w/w) and free cell probiotics during storage, respectively.
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    Item type:Publication,
    Impact of processing method and growing location on overall differences of brewed coffee using electronic tongue and sensory panel
    (2017-11-25)
    Kulapichitr, F.
    ;
    Suppavorasatit, I.
    ;
    Borompichaichartkul, C.
    ;
    Chodjarusawad, T.
    ;
    Phatthara-aneksin, A.
    Arabica coffee beans from two different locations (Doi Tung and Doi Chang, Chiang Rai, Thailand) were processed through civet cat (free-range), civet cat (caged) and normal wet processing. The beans were ground and brewed using a standard steeping method. Coffee samples were evaluated using an electronic tongue and a sensory panel for overall differences. Coffee samples from different processes and locations were clearly differentiated by the electronic tongue. Differences between the processes (civet cat (free-range), civet cat (caged) and normal wet-processing) were perceivably significant (>78% clearly detecting differences) between coffees from the same location (Doi Tung). However, when the location factor was introduced (Doi Chang vs. Doi Tung), the differences were reduced, and only civet coffee from different locations and different feeding methods (free-range vs. caged) was significantly different. Postharvest processing of coffee beans had a great impact on a cup of coffee; however, this impact seemed to be masked by the different locations.
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    Item type:Publication,
    Differences in volatile compounds and antioxidant activity of ripe and unripe green coffee beans (Coffea arabica L. ‘Catimor’)
    (2017-11-25)
    Kulapichitr, F.
    ;
    Borompichaichartkul, C.
    ;
    Pratontep, S.
    ;
    Lopetcharat, K.
    ;
    Boonbumrung, S.
    Aroma characteristics and antioxidant activity are main quality markers for a good cup of coffee. These attributes are influenced by the degree of ripeness of the coffee berries. Therefore, the aim of this study was to study the differences between ripe and unripe green coffee beans in volatile compounds and antioxidant activities to evaluate the selection process of coffee berries. Two types of green coffee beans processed from ripe and unripe coffee berries from the same plantation were characterized for their volatile components by solid-phase micro-extraction gas chromatography/mass spectrometry (SPME-GC/MS) using 2-methyl-3-heptanone as an internal standard. More than 200 peaks of volatile constituents were found in both unripe and ripe green coffee. Alcohols and ketones were the most abundant groups of volatile compounds in unripe green coffee, while the concentrations of these two groups decreased during the ripening process. In contrast, aldehydes, acids, and esters increased. Various compounds were found only in ripe green coffee, such as 1-hexanol, 2-heptanol, 2-ethyl-1-hexanol, 2,2-dimethyl-3-4-pentadienal, methyl hexanoate, methyl phenylacetate, methyl salicylate, methyl-(2E)-2-methyl-2butenoate, and 2,7-dimethyl-oxepine. In terms of antioxidant activity measurements, total phenolic content of ripe and unripe green coffee beans was 59.94±4.14 and 54.56±0.73 mg gallic acid equivalents (GAE) g<sup>-1</sup> coffee beans; diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (%) was 71.74±5.26 and 70.68±4.78, and reducing antioxidant power by ferric-reducing antioxidant potential (FRAP) assay was 66.98±4.70 and 52.72±3.20 mg Trolox g<sup>-1</sup> coffee beans, respectively. These results can be used as information for correct selection of coffee berries prior to other stages of coffee processing.