As a principal pigment in plants, chlorophyll a (Chl a) is widely used to evaluate quality changes and senescence process during storage of leafy vegetables. The determination of Chl a in plant extracts by spectrophotometric methods using various empirical equations is often unreliable. Considering the sensitivity of fluorescence detection, we report here a simple, inexpensive spectrofluorimetric method that can detect and quantify Chl a in plant extracts. The fluorescence standard used for the quantitative determination of Chl a was isolated in our laboratory from the extract of Anthrospira platensis (Spirulina). The method proved to be reliable, fast, and low cost in a study of the influence of the most commonly used domestic storage conditions on Chl a degradation in fresh-cut arugula.
In our study, using a combination of eye-tracking parameter analysis and the van Westendorp method, we investigate whether participants pay more attention to products that they perceive as more expensive or to those that they prefer in the ranking process. The experiment involved 50 participants, a questionnaire with ranking and pricing tasks, and an eye-tracking measurement. Three wine varieties (Irsai Olivér, Rosé and Merlot-Shiraz) and three different label alternatives were tested. When comparing the results of the ranking and the pricing tasks, the product that is considered more expensive is not always the one that is most appealing to the participants. If we compare the results from the analysis of the eye-tracking parameters and the pricing, we can say that in all cases the labels that received the most visual attention were those that were priced more expensively by the participants.
Thermobifida alba is the mesophilic member of the Thermobifida genus, the genome and enzyme sets of which have not been described and published yet. Thermobifida strains are thermotolerant actinomycete, which possess wide sets of cellulose and hemicellulose hydrolysing enzymes. Previously, three endomannanases (Man5ATh, Man5ATc, and Man5AThf) of thermobifidas were cloned and investigated, and hereby the endomannanase of T. alba DSM 43795 is described. All four endomannanases belong to the glycoside hydrolase family 5, their sizes are around 50–55 kDa. Their structure consists of a catalytic domain and a carbohydrate binding module, while there is an interdomain linker region in-between consisting repetitive tetrapeptide motifs (eg.: PPTEPTD-Ta, PTDP-Tc, TEEP-Tf, DPGT-Th). The pH optima of Man5A enzymes from T. alba, Thermobifida halotolerans, Thermobifida cellulosilytica, and Thermobifida fusca are slightly different (6.5, 7.0, 7.5, and 8.0, respectively), however, the temperature optima of the enzymes were detected within a wider range of 65–75 °C. In this research, Man5ATa exhibited the lowest Michaelis-Menten constant (KM) (0.13 mM) on LBG-mannan substrate, while others shared similar kinetic parameters: 0.9–1.7 mM of KM. Despite the high sequence similarity of the investigated mannanases, they exhibit different temperature stability parameters. These different functional characteristics can be advantageous for industrial applications producing biologically active, oligomannan prebiotics under different conditions.
In the study, suitability of porridge, bun, and salad prepared from processed pearl millet FBC16 and sorghum PSC4 had been evaluated organoleptically by a panel of semi-trained judges and 25 non-insulin dependent diabetes mellitus subjects. Organoleptically, germinated pearl millet was found to be more suitable for porridge (50%) and salad (100%), while puffed sorghum was best suitable for bun (15%) preparation. Prepared porridge had significantly (P ≤ 0.05) higher protein (16.9%) and total phenols (178.8 mg GAE/100 g) contents and antioxidant capacity (1,036 mg TE/100 g) than control. The dietary fibre and in vitro starch digestibility of composite porridge and bun increased significantly (P ≤ 0.05). Most acceptable composition of porridge, bun, and salad had low glycaemic index (17.64–26.79) and medium to low glycaemic load (8.82–13.40). Suitability of pearl millet and sorghum using appropriate processing techniques (germination and puffing) is recommended for preparation of indigenous food products especially for diabetics.
This study aimed to investigate the anti-obesity potential of camel colostrum and milk proteins as well as their enzymatic hydrolysates. Camel colostrum and milk proteins were treated using six proteolytic enzymes (pepsin, trypsin, α-chymotrypsin, pancreatin, papain, and pronase). The degree of hydrolysis was measured to verify the degradation of proteins. The in vitro anti-obesity activity was evaluated using the pancreatic lipase inhibitory assay. Camel colostrum and milk protein hydrolysates exhibited different degrees of hydrolysis ranging from 17.69 to 43.97%. The protein content varied between 56.08–61.95% and 37.39–41.72% for camel colostrum and milk protein hydrolysates, respectively. The hydrolysates displayed significantly higher anti-obesity activity than the undigested proteins at all tested concentrations (P < 0.05). Colostrum protein hydrolysate generated with pancreatin had the highest anti-obesity potential (59.92%). These results suggest that colostrum and milk protein hydrolysates could be used to formulate functional foods and nutraceuticals.
In the modern era, nutraceutical properties of horticultural crops are indispensable to determine their adaptability to different agro-ecological regions. The present study exploits the potential of mulches (P: plastic mulch; S: straw mulch; N: No mulch) in relation to drip irrigation (I1: 100%, I2: 80%, I3: 60% of crop evapotranspiration (Etc)), and fertigation (F1: 100%, F2: 80%, F3: 60% of recommended dose of fertilizer (RDF): 125 kg N, 62.5 Kg P2O5, 62.5 kg K2O per ha) on Pak choi at three maturity stages in the North West region of India. Plant fresh weight was the highest at 55 days after transplanting (DAT); however, maximum soil plant analysis development (SPAD) values were registered at 45 DAT. Antioxidant activity, FRAP, DPPH, phenols, flavanols, total sugars, ascorbic acid, free amino acids, and irrigation water use efficiency were observed significantly higher in plants grown on plastic mulch at different levels of irrigation and fertigation. It is envisioned that Pak choi plants had the highest nutritional value at 45 DAT from plots mulched with silver-black, irrigated at 80% Etc, and fertigated at 100% RDF. The nutrient enriched plants are used for green salad and as ingredients for the preparation of many recipes in the semi-arid and sub-tropic areas of India.
This paper explores the prediction of the soluble solid content (SSC) in the visible and near-infrared (400–1,000 nm) regions of Baise mango. Hyperspectral images of Baise mangoes with wavelengths of 400–1,000 nm were obtained using a hyperspectral imaging system. Multiple scatter correction (MSC) was chosen to remove the effect of noise on the accuracy of the partial least squares (PLS) regression model. On this basis, the characteristic wavelengths of mango SSC were selected using the competitive adaptive reweighted sampling (CARS), genetic algorithm (GA), uninformative variable elimination (UVE), and combined CARS + GA-SPA, CARS + UVE-SPA, and GA + UVE-SPA characteristic wavelength methods. The results show that the combined MSC-CARS + GA-SPA-PLS algorithm can reduce redundant information and improve the computational efficiency, so it is an effective method to predict the SSC of mangoes.
This paper provides a rapid method coupled with chemometrics to visualise PEL quality of eight regions. The contents of mineral elements, Vitamin C (Vc), and colour parameters were measured using spectrophotometric methods. The volatile substances were determined by electronic nose (E-nose) and headspace solid phase micro-extraction with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Chemometric analyses were employed to visualise the sample distribution according to the geographical origin. The colour parameters, Vc, and mineral contents of PEL from diverse origins were significantly different (P < 0.05). A total of 25 volatile organic compounds (VOCs) were identified from PELs, with the highest percentage of components being ethyl acetate. The combination of HS-SPME/GC-MS and E-nose can properly characterise PEL samples. Therefore, the results of this exploratory work highlight the possibility of discriminating PEL from different regions.
Synthesis of nanoparticles can be long and costly processes using physical and chemical methods. Biological synthesis of nanoparticles is known to be cheaper and easier than other methods. In this study, silver nanoparticles (AgNP) were obtained by biological synthesis, also known as green synthesis, using Sorghum bicolor var. technicum (Körn) Stapf ex Holland seed extract, popularly known as sorghum. AgNPs were characterised by SEM, EDS, TEM, FT-IR, and UV-Vis Spectroscopy. SEM images confirmed that the shape of AgNPs was spherical. TEM analysis showed that the average sizes of AgNPs ranged from 51 to 56 nm. EDS analysis confirmed the presence of AgNPs by detecting a silver ion peak at 3 KeV. UV-Vis spectroscopy analyses indicated that the brown-burgundy colour of AgNPs exhibited maximum absorbance at 450 nm. The biological activities of the extract and AgNPs were investigated through antimicrobial, antibiofilm, antioxidant, mutagenic, and DNA cleavage activity analyses. The extract exhibited the highest MIC value against Gram-positive bacterium Bacillus subtilis (0.62 μg mL−1), whereas AgNPs demonstrated the highest antimicrobial activity specifically against Gram-negative bacterium Escherichia coli (0.31 μg mL−1). The antibiofilm results revealed that the extract displayed the highest percentage of biofilm inhibition against B. subtilis, while AgNPs exhibited notable efficacy against both Candida albicans yeast and Pseudomonas aeruginosa bacterium. The antioxidant activities were evaluated using DPPH• and ABTS•+ methods, and it was determined that both samples had high antioxidant activity. Mutagenicity of the extract and AgNPs were evaluated by the Ames/Salmonella test using two strains of Salmonella typhimurium (TA98 and TA100). The mutagenic activity of the extract increased depending on the concentration for both strains, while AgNP did not show mutagenicity at any concentration. The agarose gel electrophoresis method showed that the extract and AgNPs cleaved DNA in the presence of an oxidising agent.
In this study, a water-soluble novel polysaccharide called TPS was successfully prepared and isolated from Liubao tea. The optimal extraction conditions resulted in a yield of 10.70% for the crude TPS. The purified TPS exhibited unique physicochemical properties and structural characteristics. It was identified as an acidic polysaccharide with trace binding proteins, with a →4)-α-D-Galp-(1→) residue. The purified TPS had a dense and uneven appearance, potential crystallisation characteristics, and structural stability. Importantly, it demonstrated the ability to inhibit glucose transport in Caco-2 cells by down-regulating the expression of sodium/glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2), leading to a hypoglycemic effect. These findings highlight the potential of TPS from Liubao tea as a functional food or additive with hypoglycaemic properties.