Effect of lyoprotectants on β-glucosidase activity and viability of Bifidobacterium infantis after freeze-drying and storage in milk and low pH juices

The benefit of disaccharide protectants for maintaining viability and β-glucosidase activity of Bifidobacterium infantis UV16PR during freeze-drying and storage in different food matrices was investigated. Protectants used were cellobiose, lactose, sucrose and trehalose.     

Freezing-induced changes in goat cheese: Effect of freezing rate,storage and freeze–thaw cycles

This study compared the effect of various freezing set-ups [freezing in the walk-in freezer (WF), blast freezing and liquid nitrogen freezing (LNF)] on the textural properties of goat cheeses. The influences of freeze–thaw cycles (1, 3 and 5) and storage time (1, 7 and 14 days) at 4°C on the hardness and visual appearance were investigated. The results showed that freezing damaged the cheese structure, particularly for WF. Frozen samples were not suitable for 4°C storage. Freeze–thaw cycles further damaged the texture of both cheese logs and crumbles, resulting in increased dryness. The development of the dry structure was faster for the LNF-treated sample.     

Assessment of GH1, CAPN1 and CAST polymorphisms as markers of carcass and meat traits in Bos indicus and Bos taurus–Bos indicus cross beef cattle

The objective of this study was to investigate the effects of bovine GH1, CAPN1 and CAST gene polymorphisms on carcass and meat traits in Nellore and Nellore x Bos taurus beef cattle. Three hundred animals were genotyped for GH1/MspI (TC/G in intron 3), CAPN316 (AF_252504.2:g.5709C > G) and CAST/RsaI (AY_008267.1:g282C > G) and phenotyped for rib eye area, backfat thickness, intramuscular fat, shear force (SF), and myofibrillar fragmentation index (MFI). No significant associations were observed between the GH1/MspI and CAST/RsaI polymorphisms and phenotypes, although the relation between the CAST/RsaI genotypes and meat tenderness evaluated by MFI approached significant. The fact that the CAPN316 polymorphism did not show adequate segregation in Nellore cattle confirms the difficulty of using this marker in breeding programs of different Bos indicus breeds. However, the positive results of the association analysis obtained for Nellore x B. taurus crosses contributed to the validation of previous findings.     

Evaluation of the volatile profile of 33 Pyrus ussuriensis cultivars by HS-SPME with GC–MS

Evaluation of the volatile compounds in fruit provides useful information for plant breeding for improved fruit aroma. In this study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–mass spectrometry (GC–MS) was used to assess the volatile profile of 33 cultivars of the Chinese pear Pyrus ussuriensis. In all, 108 volatile compounds were identified and there were significant differences in the composition and concentration of volatiles among cultivars. On the basis of principal components analysis (PCA), the cultivars could be divided into four groups: Group 1 contained Reli, Jinxiang, Hongbalixiang, Baibalixiang and Fuwuxiang, cultivars with a high concentration of esters and a low concentration of hydrocarbons. Group 2 contained Qiuxiang, Fuanjianba, Longxiang, Guanhongxiao, Shanli24 and Wuxiangli, cultivars with high concentrations of hydrocarbons and low concentrations of esters. Group 3 contained Shatangli and Manyuanxiang, cultivars with high concentrations of aldehydes. Group 4 contained the other 25 cultivars.     

Acrylamide–asparagine relationship in baked/toasted wheat and rye breads

Acrylamide in baked and toasted wheat and rye bread was studied in relation to levels of asparagine in flour, dough, bread and toasts. Asparagine was consumed during bread preparation resulting in reduced acrylamide content in the products. In wheat bread, 12% of the asparagine initially present in the flour (0.14 g kg^?1) remained after yeast fermentation and baking; for rye bread, 82% of asparagine remained after sourdough fermentation and baking. Asparagine present in untoasted wheat bread had totally reacted after hard toasting. Toasted wheat and rye bread slices contained 11–161 and 27–205 µg kg^?1 acrylamide, respectively, compared to untoasted wheat and rye bread with <5 and 7–23 µg kg^?1 acrylamide, respectively. The dietary intake of acrylamide from bread (untoasted) of 2 µg day^?1 is relatively low; however, acrylamide exposure from bread increases several fold for people eating toasted bread.     

Relationship between sensory analysis,penetrometry and visible–NIR spectroscopy of apples belonging to different cultivars

Nineteen French apple cultivars were characterised by sensory profiling, penetrometry and visible/near infrared (vis/NIR) spectroscopy. The main purpose was to investigate the relationships between sensory attributes, including apple texture and flavour, and destructive penetrometric measurements and non-destructive vis/NIR spectroscopy. Sensory crunchiness, touch resistance and crispness correlated well with total puncture force, flesh rupture breakdown force, and the work associated with that force. Juiciness and mealiness, two very important quality indices, were strongly correlated with the slope of force-deformation curves. A relationship was also found between different vis/NIR wavelengths and sensory attributes for apples (roughness, crunchiness, mealiness, sour and sweet taste). Subsequent studies will investigate the possible benefit of using vis/NIR spectroscopy to estimate certain sensory attributes measured by trained panellists.     

Effect of α-tocopherol on lactone formation in marbled beef and changes in lactone volatility during storage

Dynamic-headspace sampling with a standard-addition method was employed to quantitatively analyze aliphatic lactones in rendered fat from marbled beef and to evaluate the effect of the matrix on volatility. Further, the effects of different levels of the antioxidant α-tocopherol on lactone formation were examined. The slopes of the linear regression curves from the standard-addition method were significantly changed (P < 0.05 or 0.01) for all lactones after storage, with the exception of γ-octalactone, indicating the volatility of the longer-chain lactones were increased after storage. The concentrations of γ-lactones were increased after 7 d of storage at 2 °C (P < 0.01), and the α-tocopherol content in the meat affected the formation of γ-octalactone (P < 0.05) and γ-nonalactone (P < 0.01). The greatest increase was observed for γ-nonalactone in the lowest α-tocopherol (2.9 ppm) group: the concentration of 51.4 ppb was 11.7-fold higher than that before storage. Meanwhile, δ-tetradecalactone in the highest α-tocopherol (28.8 ppm) group showed the highest concentration for the lactones at 415.8 ppb, which was 2.6-fold higher than the concentration before storage. The effect of α-tocopherol was unclear for the δ-lactones. The results indicate that most of the γ-lactones are produced by oxidation during storage but that the other lactones are also generated by other processes as well.     

Monitoring of physical–chemical and microbiological changes in fresh pork meat under cold storage by means of a potentiometric electronic tongue

This work describes the correlation found along 10 days between potentiometric measurements obtained by using an electronic tongue and the variation in certain physicochemical, microbial and biochemical parameters measured on a whole piece of pork loin stored under refrigeration. The electronic tongue consists of a set of six electrodes made of Au, Ag, Cu, Pb, Zn and C, and a reference electrode. Through the use of various multivariate analysis techniques, such as: PCA and two types of artificial neural networks (i.e. multilayer perceptron (MLP) and fuzzy ARTMAP) it was found that it is possible to determine the time elapsed in relation to the degradation of the loin by using simple potentiometric measurements. Additionally, in the same pork sample used to measure redox potentials with the electronic tongue, the following parameters were also determined; pH, microbial count, concentrations of inosine 5′-monophosphate (IMP), inosine (Ino) and hypoxanthine (Hx). Through the use of PLS analysis, it was found a rather good correlation between pH and the potentiometric data. Also a remarkable correlation was observed between the measures carried out with the electronic tongue and the so-called K-index that simultaneously measures the variation in the adenosine triphosphate (ATP) degradation products. These results suggest that this simple, or a similar electronic tongue, could be useful for the undemanding qualitative or semi-quantitative evaluation of freshness in meat samples in a wide range of situations.     

Relevance of the air–water interfacial and foaming properties of (modified) wheat proteins for food systems

A shift from animal protein- to plant protein-based foods is crucial in transitioning toward a more sustainable global food system. Among food products typically stabilized by animal proteins, food foams represent a major category. Wheat proteins are ubiquitous and structurally diverse, which offers opportunities for exploiting them for food foam and air–water interface stabilization. Notably, they are often classified into those that are soluble in aqueous systems (albumins and globulins) and those that are not (gliadins and glutenins). However, gliadins are at least to an extent water extractable and thus surface active. We here provide a comprehensive overview of studies investigating the air–water interfacial and foaming properties of the different wheat protein fractions. Characteristics in model systems are related to the functional role that wheat proteins play in gas cell stabilization in existing wheat-based foods (bread dough, cake batter, and beer foam). Still, to further extend the applicability of wheat proteins, and particularly the poorly soluble glutenins, to other food foams, their modification is required. Different physical, (bio)chemical, and other modification strategies that have been utilized to alter the solubility and therefore the air–water interfacial and foaming properties of the gluten protein fraction are critically reviewed. Such approaches may open up new opportunities for the application of (modified) gluten proteins in other food products, such as plant-based meringues, whippable drinks, or ice cream. In each section, important knowledge gaps are highlighted and perspectives for research efforts that could lead to the rational design of wheat protein systems with enhanced functionality and overall an increased applicability in food industry are proposed.     

Physicochemical properties and freeze–thaw stability of rice flour blends among rice cultivars with different amylose contents

Food Science and Biotechnology - The effectiveness of the rice flour blends (RFB) for improving the processing suitability of Dodamssal rice flour (DD), a functional rice variety with a relatively...     

Correlation of rainfall and levels of deoxynivalenol in wheat from Uruguay, 1997–2003

A total of 286 wheat samples for human consumption collected during 1997–2003 from four wheat-producing localities of south-western Uruguay were screened for deoxynivalenol (DON). Quantification was carried on by an immunochemical method using immunoaffinity columns and fluorimetric detection. The incidence of DON was high during the whole survey (58.5–100%), except in 1998 and 1999 in which no contamination occurred. During 2001 and 2002, 100% of samples contained detectable levels of DON, being the mean DON contents 6593 and 5880 µg kg^?1, respectively. The annual maximum levels ranged from 8800 to 11,400 µg kg^?1. A positive correlation between DON levels and precipitation was seen. The 70% of wheat samples destined for human consumption were contaminated with DON. To avoid the introduction of contaminated materials into the food chain process, the adoption of regular screening of the DON level in wheat is recommended, particularly in years with heavy rainfall during the flowering-to-early stages of grain maturity months.     

HPLC–MS identification and quantification of flavonol glycosides in 28 wild and cultivated berry species

Berries and red fruits are rich dietary sources of polyphenols with reported health benefits. More than 50 different flavonols (glycosides of quercetin, myricetin, kaempferol, isorhamnetin, syringetin and laricitrin) have been detected and quantified with HPLC–MSⁿ in fruits of blueberry, bilberry, cranberry, lingonberry, eastern shadbush, Japanese wineberry, black mulberry, chokeberry, red, black and white currants, jostaberry, red and white gooseberry, hardy kiwifruit, goji berry, rowan, dog rose, Chinese and midland hawthorn, wild and cultivated species of blackberry, raspberry, strawberry and elderberry. The phenolic constituents and contents varied considerably among the analyzed berry species. Elderberry contained the highest amount of total flavonols (450–568 mg kg⁻¹ FW), followed by berry species, containing more than 200 mg kg⁻¹ FW of total: chokeberry (267 mg kg⁻¹), eastern shadbush (261 mg kg⁻¹), wild grown blackberry (260 mg kg⁻¹), rowanberry (232 mg kg⁻¹), american cranberry (213 mg kg⁻¹) and blackcurrants (204 mg kg⁻¹). Strawberry (10.5 mg kg⁻¹) and white currants (4.5 mg kg⁻¹) contained the lowest amount of total flavonols. Quercetins represent the highest percentage (46–100%) among flavonols in most analyzed berries. In wild strawberry and gooseberry the prevailing flavonols belong to the group of isorhamnetins (50–62%) and kaempferols, which represent the major part of flavonols in currants (49–66%). Myricetin glycosides could only be detected in chokeberry, rowanberry and species from the Grossulariaceae, and Adoxaceae family and Vaccinium genus. Wild strawberry and blackberry contained from 3- to 5-fold higher total flavonols than the cultivated one.     

Isolation of caffeic acid from Perilla frutescens and its role in enhancing γ-glutamylcysteine synthetase activity and glutathione level

Perilla frutescens is an annual herbaceous plant native to Asia, where its leaves are used in Asian gourmet food. Our previous study showed that the inhibition of γ-glutamylcysteine synthetase (γ-GCS) activity was remarkably recovered by pretreatment with perilla leaf extract (PLE). The objective was to fractionise PLE, and to identify the active component that is responsible for the enhancement of γ-GCS activity and glutathione (GSH) concentration. Among the five fractions from PLE, PLE-III of the ethyl acetate fraction showed the highest γ-GCS activity in a HepG2 cell experiment, and was further chromatographed. The purified compound, which enhanced γ-GCS activity, was finally identified as caffeic acid. We first report the enhancement of γ-GCS activity and GSH level in HepG2 cells by caffeic acid obtained from PLE. Our results suggest that caffeic acid may be a key factor in the chemopreventive potential of perilla leaf components by increasing de novo synthesis of GSH.     

Identification and quantification of leaf surface flavonoids in wild-growing populations of Dracocephalum kotschyi by LC–DAD–ESI-MS

Dracocephalum kotschyi Boiss. (Lamiaceae) is an aromatic and perennial herb endemic to Iran with interesting pharmacological and biological properties. The flavonoids luteolin-7-O-glucoside, apigenin-7-O-glucoside (cosmosiin), luteolin 3′-O-β-d-glucuronide, luteolin, apigenin, cirsimaritin, isokaempferide, penduletin, xanthomicrol, calycopterin and the polyphenol rosmarinic acid were identified among 13 natural populations of the plant by ESI–MS, LC–DAD and LC–DAD–ESI-MS. The plant extracts containing the identified compounds showed significant antioxidant activity, which was correlated with the flavonoid content. Additionally, leaf and stem size and geographical variability among the studied populations were correlated with flavonoid accumulation. Canonical correlation analysis was used to find a relationship between plant dimensions and phytochemical composition, and the plants with the lowest growth indices were found to have the highest levels of methoxylated flavonoids.     

Characterization of the components present in the active fractions of health gingers (Curcuma xanthorrhiza and Zingiber zerumbet) by HPLC–DAD–ESIMS

Curcuma xanthorrhiza and Zingiber zerumbet are two of the most commonly used ingredients in Indo-Malaysian traditional medicines, health supplements and tonics. Recently, a number of products derived from the aqueous extracts of these species have appeared in the market in the form of spray-dried powder packed in sachet or bottle. On-line high performance liquid chromatography, coupled with diode array detection and electrospray ion trap tandem mass spectroscopy (HPLC–DAD–ESI–MSⁿ), was used to analyze the components in the antioxidant-active fractions from the rhizomes of these species. Three components were identified from C. xanthorrhiza, including bisdemethoxycurcumin (1), demethoxycurcumin (2) and curcumin (3). The active fraction from Z. zerumbet consisted of five components, including kaempferol 3-O-rhamnoside (4), compound 5 [kaempferol 3-O-(2″-O-acetyl)rhamnoside (5a) or kaempferol 3-O-(3″-O-acetyl)rhamnoside (5b)], kaempferol 3-O-(4″-O-acetyl)rhamnoside (6), kaempferol 3-O-(3″,4″-O-diacetyl)rhamnoside (7) and kaempferol 3-O-(2″,4″-O-diacetyl)rhamnoside (8). To confirm their identities, the components from Z. zerumbet were isolated conventionally and were analyzed by spectroscopic techniques as well as by comparison with literature data.     

In vitro and in vivo assessment of cytochrome P450-mediated herb–drug interaction of Ssang-hwa-tang

We have evaluated the herb–drug interaction potential of Ssang-hwa-tang (SHT) mediated by cytochrome P450 (CYP) inhibition/induction. Further, the effects of fermentation on the CYP-mediated herb–drug interaction potential were determined. SHT showed inhibitory activity toward CYP1A2, but not 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, and 3A4 in human liver microsomes. The results of the enzyme kinetic study suggested that the SHT-induced CYP1A2 inhibition is mixed reversible inhibition. The hepatic CYP expression and activity in rats treated with SHT were examined. The expression/activity of CYP2E1 increased as a result of SHT extract treatment (P < 0.005 or P < 0.001, respectively), which raises the possibility that SHT may increase the toxicity of environmental toxicants through the elevation of CYP2E1-mediated metabolic activation. SHT fermentation using Lactobacillus fermentum or Lactobacillus gasseri resulted in attenuation of the SHT-induced CYP1A2 inhibition, but not CYP2E1 induction, suggesting that changes in the chemical composition of SHT through fermentation can affect the inhibition of CYP1A2 activity.     

Encapsulation of probiotic Lactobacillus bulgaricus in alginate–milk microspheres and evaluation of the survival in simulated gastrointestinal conditions

In this paper, a new encapsulation carrier was applied in order to improve the survival of Lactobacillus bulgaricus (L. bulgaricus). L. bulgaricus was encapsulated in alginate–milk microspheres prepared by extrusion method. Around 100% encapsulation yield was achieved. The tolerance of encapsulated L. bulgaricus to adverse environments such as low pH (pH 2.0 and 2.5), high concentration of bile salt (1.0% and 2.0%) and long time storage (1 month), was investigated. Release characteristic of encapsulated L. bulgaricus in Simulated Intestine Fluid (SIF) was also studied. The results showed that encapsulation could improve the tolerance of L. bulgaricus to adverse environments. The viability of encapsulated L. bulgaricus did not change after 120 min incubation in Simulated Gastric Fluid (SGF) pH 2.5. The viability of encapsulated L. bulgaricus could be kept more than 8 log CFU/g after 120 min incubation in SGF pH 2.0. The viability of encapsulated L. bulgaricus in 1% bile salt solution was reduced from 9.98 log CFU/g microspheres to 9.24 and 8.48 log CFU/g microspheres after 1 and 2 h incubation, respectively. Around 1.3 and 2.1 log CFU/g microspheres were reduced after 1 and 2 h exposure in 2% bile salt solution, respectively. Full viability of encapsulated L. bulgaricus could be preserved after 1 month’s storage at 4 °C. L. bulgaricus encapsulated in alginate–milk microspheres could be completely released in 1 h. These studies demonstrated encapsulation of L. bulgaricus in alginate–milk microspheres is an effective protection technique against extreme simulated gastrointestinal environment.