Band 20, Heft 2

The results of GC-MS analysis showed that the set soybean yoghurt without oil contained only two esters and one alcohol: delta-dodecalactone, 5-decanolide, and R -(−)-2-butanol. The set soybean yoghurt with olive oil was characterized by five volatile flavors: hexanoic acid, 2-nonanol, phenylacetaldehyde, 3-heptylacrolein, and acetylpyrazine. The set soybean yoghurt with coconut oil was characterized by nine volatile flavors: 5-hydroxyoctanoic acid lactone, ethyl caprylate, ethyl caprate, ethyl laurate, 2-tridecanone, dihydro-2-methyl-3(2 H )-thiophenone, lauric acid, 1-octanol, and 2-decanol. Gas chromatographic analysis showed that free fatty acid species increased in set soybean yoghurt after oil addition, which were positively correlated with volatile flavor substances. By confocal laser microscopy observation, the oil droplets in the three groups of set soybean yoghurt were reduced after digestion. Research has proved that adding an appropriate amount of olive oil or coconut oil to set soybean yoghurt can improve the flavor and does not increase the digestive burden.

For the first time, the impact of ultrasound-ethanol immersion as a non-thermal pretreatment (NTPT) and coating-blanching in starch solutions as a thermal pretreatment (TP) on the convective drying of beetroot was evaluated. The beetroot was exposed to ethanol immersion (E), ultrasound (U), and ultrasound-ethanol immersion (UE). Besides, TP pretreatment was performed by blanching the beetroot at steam (SB), water (WB), starch-coating solutions, and microwave (M). The hot air drying was conducted at 90 °C and air velocity of 1.2 m/s. The maximum decreases in the drying time were observed at UE30 (64.29 %) and the sample blanched at native corn starch solution (60.17 %). Moisture diffusion coefficients ranged from 0.851 to 2.312 × 10 −9  m 2 /s. The friction drag force, convective heat, and mass transfer coefficients were 2.840 × 10 −6  N, 59.368 W/m 2  K, and 0.0492 m/s, respectively. The thermal conductivity, specific heat, and density ranged from 0.464 to 0.615 W/m. K, 3164–4071 J/kg. K, and 798.9 to 1055.9 kg/m 3 , respectively. The maximum values of rehydration ratio at non-thermal (NTPT) and thermal pretreatments (TP) were observed at U30 and the sample blanched at the modified starch solution (MCS), respectively. The total phenolic contents of the NTP sample decreased while those for the TP samples increased due to boosted polyphenol synthesis at high temperatures. Both U and E samples caused a decrease in the total antioxidant activity, while they increased the anthocyanin content of beetroot samples. Pretreatments reduced the hardness owing to changes in the microstructure of the sample. U, E, and M pretreatments increased the brightness of samples, and the minimum color change compared with control samples was observed by UE30 pretreatment. The UE and blanching at a starch solution could be selected for improving the drying characteristics of beetroots at an industrial scale.

This study aimed to analyze the mineral profiles, physicochemical and sensory properties of pumpkin dough chips (PDC), made from pumpkin pulp ( Cucurbita moschata ) and a combination of hazelnut and grain meals fried by oven (OF), microwave (CMWF) and deep frying (DF). The experiment was established by 36 samples, including formulations ( F  = 4), frying techniques (FT = 3) and replications ( R  = 3). The effect of F , FT and F  × FT factors on the moisture, ash, protein, oil, hydroxymethylfurfural, phenolics, DPPH-RSA, TEAC, β -carotene, Hunter L* , a* , b* , browning index, hardness, fracturability and minerals of PDC were found significant statistically ( P  < 0.05). As a result of ICP-MS analysis of PDCs, K, Na, Ca, Mg, and Si minerals were higher than other minerals. While the OF chips had most appreciated, panellists found the DF chips oily. Also, there was a harmony between the pumpkin in the PDC and the cereal flours and hazelnuts.

The aim of this study was to investigate the changes in the quality of fish ( Argyrosomus regius ) and shrimp ( Penaeus japonicus ) cooked with sous-vide. Vacuum-packed fish fillets and shrimps were cooked with the sous-vide method under different temperature-time conditions and stored at 3 °C. Lower volatile bases and trimethylamine were found with cooking sous-vide than in control samples (cooked in an oven). Microbiological analysis results showed that the sous-vide cooking method provides bacterial inhibition in fish and shrimp. The sensory properties of samples cooked with sous-vide were found to be better than those of the traditional method. Sous-vide cooking did not affect the L* value of fish but affected that of shrimp. Sous-vide cooking resulted in higher a* values and lower hardness, gumminess, and chewiness values. As a result, sous-vide cooking increased the shelf life of fish and shrimp, reduced cooking loss, preserved color and texture, and provided microbial safety.

Refractance window drying (RWD) is a preferred drying technique due to its suitability for heat-sensitive products. Although this drying technique appears promising, it is yet largely unexplored. In this study, the authors provide a review of the existing milestones on RWD using a sample of 40 articles from 2000 to date to quantify the state of investigations across multiple studies and establish specific areas needing further attention. Results show that experimental analyses constitute about 53–59 % of the reported cases, followed by a literature review 24–28 %. Furthermore, 17 % of the total study cases was observed across all modelling categories, with machine learning (ML) techniques constituting only about 8 %. Driven by the outcome, this study thus utilized three ML techniques to model the moisture ratio (MR) of 1.5–4.5 mm thick yam slices, operated over the range of 65–95 °C temperature in an RWD chamber. Unlike the routine procedures, the yam thickness versus air temperature effects on moisture ratio were investigated to determine the more significant factor as well as the air velocity effect or its lack thereof on MR. To investigate the validity window for the entire dataset, all data points were considered, with a training-testing ratio of 7:3 used in each case. For scenario one, prediction based on the yam thickness effect showed a greater influence on the MR. The air velocities at 0.5–1.5 m/s had little effect on MR as compared to the case where air velocity was ignored (i.e., the control case in this study). Also, model accuracy for all tested samples has been determined to be better than 93 %. Insight from this study is to guide in the future design of RW dryers for direct measurement of the moisture ratio of harvested root tubers at various conditions.

Atractylodes chinensis volatile oil (ACVO) microcapsules were prepared with chitosan as parietal material. The optimal conditions for encapsulation were investigated by the Response Surface Method (RSM). ACVO microcapsules were characterized by scanning electron microscopy (SEM), particle size analyzer and Fourier Transform infrared spectroscopy (FTIR), respectively. In vitro release properties of ACVO microcapsules were investigated at pH 1.5 and 7.4, respectively. The effects of ACVO microcapsules on the length of rat gastric smooth muscle cells (GSMC), mRNA and protein expression of calmodulin (CaM) and myosin light chain kinase (MLCK) were investigated. Results showed that under optimal conditions, encapsulation efficiency (EE) was 82.19 %. ACVO microcapsules were spherical with a particle size of 1100 nm. ACVO microcapsules had a good release profile at pH 1.5, and the cumulative release within 72 h reached 85.32 %. Cell experiments showed that ACVO microcapsules (0.02, 0.04 μg/mL) had no effect on cell activity, while induced GSMC to contract, and improved the mRNA, protein expressions of CaM and MLCK in GSMC.