Inactivation efficacy of plasma-activated water: influence of plasma treatment time,exposure time and bacterial species

This study aimed to evaluate the influence of plasma treatment time, bacterial exposure time to PAW and bacterial species on the inactivation efficacy of plasma-activated water (PAW), with additional investigation of the inactivation mechanisms of PAW. Six bacterial species, including Listeria innocua, Staphyloccus aureus, Escherichia coli, Pseudomonas fluorescens, Shewanella putrefaciens and Aeromonas hydrophila were selected as the representative bacteria. The initial bacterial concentration was around 7 log CFU ml⁻¹ after mixing with PAW, and the inactivation efficacy was measured after different exposure times during the 4 °C storage. Scanning electron microscopy (SEM) images of the bacteria after PAW treatment were carried out to inspect the cell structure damage, and physicochemical properties of PAW, including pH, conductivity and long-living reactive species of H₂O₂, , and , were examined. The results showed that the inactivation efficacy of PAW was positively correlated with plasma treatment time and bacterial exposure time, and for the species examined in this study, the Gram-negative species were more sensitive to PAW than the Gram-positive species. Cell structure damage, including shrinkage, distortion, or holes, was observed after PAW treatment. The pH of PAW was acidified to 2.5–2.9, and conductivity was significantly increased to 518.0 μs cm⁻¹. and H₂O₂ were reduced during the 48 h storage, while an increased concentration was observed for . This study demonstrated that the processing parameters of plasma treatment time, exposure time and characteristics of bacteria can significantly affect the inactivation efficacy of PAW.     

Stenocereus griseus (Haw) pitaya as source of natural colourant: technological stability of colour and individual betalains

Stenocereus griseus pitaya has been evaluated as potential natural colourant on the basis of tristimulus colorimetry, differential colorimetry, and individual betalains, not previously conducted in conjunction with this raw material. Different technological treatment conditions were reproduced based on different pHs, temperatures and storage time. According to the results, cold temperatures (4 °C) maintained for longer the initial colour characteristics (L*, and h_ab) of the extracts, whereas h_ab modifications began from the commencement of treatment at room temperature. Highly acidic extracts (pH 4) were the most stable samples in the light of the lower h_ab and changes over time, even at room temperature. Betanin, isobetanin, betanidin and 2-decarboxy-neobetanin were more affected by temperature, whereas the content of the minor betalains significantly (P < 0.05) varied when pH was modified. Moreover, visually appreciable and quantitative colour changes (Δ > 3) were observed among all pH values and temperatures.     

Real-time quality authentication of honey using atmospheric pressure chemical ionisation mass spectrometry (APCI-MS)

The aim of this study was to use gas chromatography-mass spectrometry (GC-MS) and APCI-MS techniques to detect adulteration in honey. The key volatile compounds in the headspace of the adulterated honey were marked by GC-MS and their representative fragment ions were utilised in scanning honey samples using the real-time APCI-MS system. The PLS models validated using independent data sets resulted in coefficient of the determination () of 0.97 and 0.96 and root mean square error in prediction (RMSEP) of 2.62 and 2.45 for the GC-MS and APCI-MS data sets respectively. The most efficient volatiles from GC-MS analysis and their corresponding fragment ions m/z from APCI-MS data analysis were then identified and used to develop new PLS models to predict the level of adulteration. The best PLS model gave of 0.95 and RMEP of 2.60% in the independent validation set indicating that the model was very accurate in predicting the level of adulteration.     

Noodle processing,storage time and cooking affect the antioxidant activities and phenolic compounds content of Qingke barley noodles

The impact of noodle processing, storage and cooking on the total phenol content (TPC) and total flavonoid content (TFC) was assessed. Total phenol content (TPC) and total flavonoid content (TFC) of mixed flour were 77.50 and 39.56 mg per 100 g, respectively, and it decreased to 71.80 and 36.30 mg per 100 g after noodle processing. For the fresh Qingke barley noodles (FQBNs), stored at 25 °C, both TPC and TFC decreased significantly during storage. After cooking the fresh noodles, the TPC of the noodles stored for 0 and 4 h increased, while it decreased for the noodles stored for 8, 16 and 24 h; the TFC of all cooked Qingke barley noodles (CQBNs) decreased. Compared with the flour, the DPPH^•, ABTS^•+, HO^• and scavenging ability and ferric reducing antioxidant power (FRAP) decreased significantly (P < 0.05) after noodle processing. For FQBN, increased storage time led to a reduction in antioxidant ability. After cooking, the DPPH^• and HO^• scavenging ability and FRAP of noodles stored at 25 °C for 0 and 4 h, and the ABTS^•+ and scavenging ability of noodles stored at 25 °C for 0, 4 and 8 h increased. Overall, noodle processing, storage and cooking will affect the phenolic compound content and antioxidant activities of barley noodles. Although the shelf life of FQBN is 17 h at 25 °C, from the perspective of nutrition, it is not suitable for long-term storage, and it is best choice to consume it within the first 4 h.     

Acid-induced aggregation and gelation of heat-treated chia proteins

This work studied for the first time the acid-induced aggregation and gelation of heat-treated chia protein isolates obtained by extraction at pH 10 or 12 (CPI10 and CPI12, respectively). The aggregation state of proteins was modified during acidification. The size of the aggregates was reduced for both samples when the pH decreased but below pH 4.5 further protein aggregation took place for CPI12. Gelation of CPI12 was completed after about 30 min of acidification with glucone-δ-lactone. By contrast, this period was not enough to reach a constant value in G′ for CPI10. When gelation was ensured, confocal laser scanning micrographs from those gels revealed a coarse and irregular structure with large pores (median size of diameters: 30 μm). Instead, micrographs from CPI12 cold gels showed a more regular and interconnected network, with smaller pores (median size of diameters: 9 μm). These differences are consistent with a higher elastic behaviour ( = 13.6 ± 0.1 Pa).     

Effects of state/phase transitions on the quality attributes of mango (Mangifera indica L.) during frozen storage

Effects of different state/phase transitions (temperature fluctuations) on quality attributes of mango cubes during frozen storage were investigated. Temperature of frozen mango was modulated from ?65 °C to different states, namely, rubbery state , partially freeze‐concentrated state () and glassy states ( and ). Results revealed that frozen samples after 4 weeks of storage in a glassy state showed higher quality in hardness, drip loss, colour and ascorbic acid. Quality of mango still continued to change during frozen storage even in the glassy state without temperature fluctuations. Furthermore, there was a significant decrease in quality attributes of frozen mango subjected to temperature fluctuations above and . Current work indicates glassy state storage can improve retention of quality attributes in frozen mango and glassy state without temperature fluctuation was proposed as the most favourable frozen storage condition.     

Phenolic profile and changes in the antioxidant activity of crabapple (Malus domestica cv Royalty) fruit during maturation on the tree

The fruits of crabapple (Malus domestica cv Royalty) harvested at six times during fruit maturation on the tree (60, 80, 100, 120, 140 and 160 day after full bloom, DAFB) were evaluated for their antioxidant potentials by various assays such as DPPH, ABTS, superoxide anion, hydroxyl radical and ferric reducing power. Total phenolic and flavonoid were analysed and characterised using HPLC‐DAD‐MS/MS. Results showed that the Royalty fruits harvested on 60 DAFB had the strongest scavenging activity against DPPH, ABTS and radicals ( = 0.37 mg mL^?1,  = 0.19 mg mL^?1 and  = 4906.63 U L^?1) and ferric reducing power (FRAP = 2.85 mol Fe²⁺ per kg dw), which highly correlated with its high amount of total phenolics of 130.17 mg gallic acid equivalents (GAE) per gram dry weight and total flavonoid of 866.15 mg rutin equivalents (RE) per gram dry weight. Eight phenolic compounds were identified in the Royalty extract of 60 DAFB as caffeic acid, eriodictyol rhamnoside, phloretin hexoside I, coumaroyl guinic acid, quercetin hexoside, phloretin hexoside II, quercetin pentoside and quercetin rhamnoside. These findings suggest that Royalty could be potentially used as a promising source of natural antioxidants in the development of functional foods.     

Powdered barley sprouts: composition,functionality and polyphenol digestibility

This study was performed to evaluate the phytochemical composition, in vitro antioxidant capacity, antihyperglycaemic and anti‐inflammatory activities, and simulated gastrointestinal digestion of 7‐day‐old freeze‐dried barley sprouts (BS), one hybrid and one nonhybrid variety: ‘NS565’ (BSNS) and ‘Golozrni’ (BSG), respectively. BSNS expressed significantly higher (P ≤ 0.05) content of total phenols, chlorophyll and carotenoids. Phenolic compounds were the most dominant bioactives in both BSNS and BSG (713.25 and 479.02 mg GAE 100 g^?1 DW, respectively). BSNS possessed significantly higher (P ≤ 0.05) antioxidant capacity, evaluated by DPPH and ABTS assays, and reducing power ( = 0.54 mg mL^?1; IC₅₀^ABTS = 0.79 mg mL^?1; RP_0.5 = 9.35 mg mL^?1). Antihyperglycaemic and anti‐inflammatory activities of BSNS ( = 1.43 mg mL^?1;  = 1.86 mg mL^?1) were also significantly higher (P ≤ 0.05) than BSG ( = 1.97 mg mL^?1;  = 4.40 mg mL^?1). In vitro simulation of gastrointestinal digestion showed higher release of phenolic compounds in intestinal fluid than in gastric fluid.     

Modelling growth of Lactobacillus plantarum and shelf life of vacuum‐packaged cooked chopped pork at different temperatures

Lactobacillus plantarum growth in a vacuum‐packaged cooked meat product under different storage temperatures (4, 10 and 16 °C) and the relation between the microorganism growth and sensory quality were investigated. The Gompertz model was fitted to experimental counts of L. plantarum showing a good fitting to growth curves at different temperatures. A root‐square secondary model and linear model were satisfactorily fitted to estimated growth rates () and lag times (), respectively. The sensory attributes (colour, flavour, taste, appearance) were also evaluated due to their importance to the global quality (Q). The sensory deterioration was detected several days after L. plantarum reached the stationary phase, that is, 59, 45 and 25 days for 4, 10 and 16 °C, respectively. According to results, sensory deterioration was related to time when microorganism reached late stationary phase, phenomenon known as ‘delayed change’.     

Non-invasive quality analysis of thawed tuna using near infrared spectroscopy with baseline correction

In order to investigate the ability of NIR spectroscopy coupled with baseline correction to detect quality-related changes of thawed tuna during the storage and the transportation. First, adaptive iteratively reweighted penalized least squares (airPLS) method was taken to eliminate the baseline and estimate spectra feature peaks of 168 samples (bigeye = 82, yellowfin = 86), and the Monte Carlo method was used to determine the optimal adjustment parameter λ . Second, predictive models based on the fitted features were established by the partial least squares regression (PLSR) to estimate docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), fat, and protein content. Compared with the standard normal variate (SNV), the proposed airPLS achieved good performance in a comparative experimental test. When the original spectra was preprocessed by airPLS, the number of feature peaks (n_f ) and the mean value of R² () achieved 6 and 0.89 respectively, which is greater than that of the preprocessing algorithm SNV (n_f = 4 and ). The proposed airPLS effectively reduces the interfering variability and reserves much more NIR features, which is a feasible and stable method for quality-related analysis of the thawed tuna. Practical application : During the storage and the transportation, the rich nutrients in tuna are easily oxidized and degraded when they are exposed to the air. In order to develop effective methods to determine the quality of tuna and avoid selling thawed products as the fresh tuna, a quality-related analysis method for thawed tuna based on the baseline correction is proposed to improve the prediction accuracy.     

Fast and non-destructive determination of simultaneous physicochemical parameters of Manihot esculenta flour using FT-NIR spectroscopy and multivariate analysis

Manihot esculenta flour (MEF) is the main energetic source for a major part of the population in the Amazonian region. In this study, near-infrared spectroscopy (NIRS) was used, for the first time, to predict physicochemical parameters of MEF. The water activity (a_W), ash content, bulk density, moisture content, pH, geometric mean diameter (GMD) and colour parameters of L*, and h_ab were determined for 106 samples of MEF. Calibration equations with independent validation were developed to predict all parameters using the partial least square regression method. The performance of models was evaluated by the root mean standard error of calibration (RMSEC) and validation (RMSEV), and R² values. The a_W (RMSEC = RMSEV = 0.05), moisture content (RMSEC = 0.35%; RMSEV = 0.45%) and pH (RMSEC = 0.16; RMSEV = 0.18) could be predicted (R² > 0.727) by NIRS coupled to multivariate analysis. NIRS and multivariate analysis proved to be a powerful tool to predict multiple physicochemical parameters of MEF.     

The effect of enzymatic hydrolysis on the biological properties of Oenothera biennis,Borago officinalis and Nigella sativa seedcake by‐products from oil pressing

The biological properties of ethanolic (50%, v/v) extracts from Oenothera biennis, Borago officinalis, Nigella sativa seedcake before and after enzymatic hydrolysis by alpha‐amylase (EC 3.2.1.1) from Aspergillus oryzae, beta‐glucosidase (EC 3.2.1.21) and beta‐glucanase (EC 3.2.1.6) from Aspergillus niger combinations in a ratio of 1:1:1 were investigated. Total phenolic, flavonoid and reducing sugar content for O. biennis extract after enzymatic hydrolysis was, respectively, 0.5, 1.5 and 2 times higher in comparison with nonhydrolysed extract. Iron‐chelating and radical‐scavenging activity of O. biennis seedcake extract after hydrolysis (IC₅₀ = 0.076 mg mL^?1 and IC₅₀ = 0.050 mg mL^?1) was at a similar level as that nonhydrolyeed (IC₅₀ = 0.070 mg mL^?1 and IC₅₀ = 0.065 mg mL^?1). The antioxidant activity was two times higher after hydrolysis than before enzymatic hydrolysis of O. biennis seedcake extract. Also strong elastase inhibition activity has been shown to O. biennis seedcake extract before (IC₅₀ = 0.095 mg mL^?1) and after enzymatic hydrolysis (IC₅₀ = 0.07 mg mL^?1), respectively. Oenothera biennis and B. officinalis seedcake extracts before and after hydrolysis have stronger antibacterial activity against Pseudomonas aeruginosa strain in comparison with N. sativa seedcake.     

Antioxidant Activity of Selenium‐Enriched Peptides from the Protein Hydrolysate of Cardamine violifolia

Cardamine violifolia is a selenium (Se)‐enriched plant found in China. In this study, the Se‐enriched peptides of C. violifolia (CP) were isolated using a 1 kDa ultrafiltration membrane after enzymatic hydrolysis by alkaline and neutral proteases. The peptides were separated by DEAE‐Sepharose FF anion‐exchange chromatography and purified using preparative high‐performance liquid chromatography (prep‐HPLC). The component with the highest antioxidant activity, CPR13, was identified by comparing the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH?), hydroxyl (?OH), 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) (ABTS⁺?), and superoxide () radical scavenging ability of each fraction. At a concentration of 0.1 mg/mL, the DPPH?, ?OH, , and ABTS⁺? scavenging activities of CPR13 were 89.2%, 26.3%, 40.6%, and 42.9%, respectively. Amino acid sequences were obtained by liquid chromatography combined with mass spectrometry as follows: GRVGSSSC, GRAGGSYM, GHPNFKLNCSGG, GTKSCKA, ASSNARDMI, TAGGCYIPI, and KNCALQ. The seleno‐amino acids were identified as selenomethionine, methylselenocysteine, and selenocysteine. Correlation analysis among organic Se content, peptide content, and antioxidant activity revealed that organic Se plays a greater role in free radical scavenging than peptides, and that the organic Se content of the Se‐enriched peptides was positively correlated with their antioxidant ability (P < 0.05). It indicated that CP has a great potential as natural functional materials for dietary supplement.     

Noninvasive sensing of thermal treatments of Japanese seafood products using imaging spectroscopy

The potential of imaging spectroscopy for noncontact sensing of thermal treatments experienced on Japanese kamaboko was investigated. Samples were thermally treated at 100, 120, 140, 160, 180 and 200 °C to core temperatures of 45, 50, 55, 60, 65, 70, 75 and 80 °C and then promptly cooled and imaged in the short‐wave near infrared spectral range of 900–2500 nm. Partial least square (PLS) regression models were developed using the whole spectral range as well as using the most important wavelengths to predict the core temperature (T_C) and thermal history (TH) yielding a reasonable level of accuracy of ( = 0.86 and RMSEP = 3.9 °C) and ( = 0.83 and RMSEP = 0.29 min), respectively. Moreover, a stepwise linear discriminant analysis (LDA) model was developed for identifying samples whose core temperatures reached a threshold of 65 °C. The LDA model yielded overall classification accuracy of 93.75% in both calibration and validation sets. The resulting discrimination function was then applied in a pixel‐wise manner to produce understandable classification maps to exhibit the difference among samples with high accuracy.     

The influence of ultrasonic modification on arabinoxylans properties obtained from wheat bran

This work is concerned with modification of wheat bran arabinoxylans by ultrasound irradiation. The average molecular weights of arabinoxylans ranging from 580 000 to 800 000 kDa were yielded by regulating ultrasonic powder (120–480 W) and treat time (15–45 min). The phenolic compounds increased after ultrasound treatment, and arabinose‐to‐xylose ratios ranged between 0.55 and 0.67. FTIR spectroscopy revealed that the major chemical composition of arabinoxylans was unchanged. The maximum storage modulus decreased with the extension of ultrasonic treatment time. The antioxidant capacity test showed that the EC₅₀ values decreased and the values from the ferric reducing antioxidant power decreased after ultrasound treatment. The results suggested that ultrasound is an effective method for the modification of arabinoxylans.     

Yak (Bos grunniens) bones collagen-derived peptides stimulate osteoblastic proliferation and differentiation via the activation of Wnt/β-catenin signaling pathway

The cover image is based on the Research Article Yak (Bos grunniens) bones collagen-derived peptides stimulate osteoblastic proliferation and differentiation via the activation of Wnt/β-catenin signaling pathway by Mengliang Ye et al., https://doi.org/10.1002/jsfa.10286 .

     

High hydrostatic pressure inactivation kinetics of the endogenous lipoxygenase in crude silver carp (Hypophthalmichthys molitrix) extract

Inactivation kinetics of endogenous lipoxygenase in crude silver carp (Hypophthalmichthys molitrix) extract was studied for thermal (50–80 °C, ambient pressure) and high hydrostatic pressure combined with heat treatment (300–700 MPa at 50–80 °C) process conditions. Lipoxygenase (LOX) inactivation followed first‐order kinetics at all pressure–temperature combinations used. Moreover, LOX inactivation rates became less pressure dependent with increasing pressure at all temperatures studied and also showed less temperature dependence of the enzyme inactivation rate at various high pressure levels tested. It is evident that inactivation kinetics is complex affected by both pressure and temperature. Therefore, response surface methodology (RSM) was attempted to investigate combined temperature–pressure processing conditions on LOX inactivation kinetics in crude silver carp extract samples. In conclusion, the LOX inactivation rate constant was modelled as a function of both temperature and pressure conditions by a quadratic polynomial equation as follows: .     

Dietary lycopene powder improves meat oxidative stability in Hu lambs

The cover image is based on the Research Article Dietary lycopene powder improves meat oxidative stability in Hu lambs by Chenchen Xu et al., DOI: 10.1002/jsfa.9282 .