A comparison of the buttermilk solids functional properties to nonfat dried milk,soy protein isolate,dried egg white,and egg yolk powders

Physicochemical (i.e., sulfhydryl group, protein, and total solubility) as well as functional properties (i.e., water-holding and fat-absorption capacity, foaming and emulsification capacity, and stability) of commercial buttermilk solids (BMS) were compared to nonfat dried milk, soy protein isolate, and dried egg yolk and egg white powders on an equivalent protein basis. BMS showed limited functional properties in water-holding capacity (0.75 g water/g protein) and fat-absorption capacity (1.2 g of oil/g of protein), and foaming capacity (0.5 ml of foam/ml of solution) and stability. However, emulsifying capacity and stability of BMS was not significantly different from other dried protein powders. Results indicated that 0.9 g of protein (approximately 0.45%, wt/vol, concentration) from BMS was needed to emulsify a maximum oil concentration of 50% in water at temperatures up to 50 degrees C. Denaturation of protein, quantified by free sulfhydryl groups, was a critical factor affecting the functionality of BMS and all other protein powders tested. The milk fat globule membrane present in BMS did not enhance either emulsifying capacity or stability.     

Technological solutions and adaptive processing tools to mitigate the impact of seasonal variations in milk composition on Cheddar cheese production—A review

Variability in milk composition and physicochemical properties impact both manufacturing process performance and the end-use functionality of cheese. Such variability may be attributed to seasonal calving patterns, production systems, breed, weather patterns, and feed type and significantly impacts concentrations of macro- and microconstituents and ultimately cheese composition and quality. This article reviews technological approaches (e.g., milk standardisation protocols and calcium addition), and predictive strategies (e.g., predictive models for coagulation and curd cutting time, in-line sensors), used to mitigate the effects of seasonal changes in milk composition and their impact on process efficacy and functionality in Cheddar cheese manufacturing.     

Indigenous enzymes in milk: A synopsis of future research requirements

Milk contains a large number of indigenous enzymes, with differing functions, stability to processing, impact on dairy products, and significance for consumer safety (e.g., antimicrobial enzymes). Some enzymes are of interest for their beneficial activity (e.g., lactoperoxidase), some for use as indices of processing (e.g., alkaline phosphatase) and some for effects on the quality of dairy products (e.g., plasmin, lipoprotein lipase), which may be either positive or negative for different products. The study of enzymes in milk is a key specialisation within both the fields of biochemistry and dairy science, and remains an active research subject. Many questions remain to be answered about the nature and significance of milk enzymes, and progress is in some cases hampered by inconsistencies in assay methodologies being used; some of these issues are discussed in this article, the content of which was generated in part by discussions at the First IDF Symposium on Indigenous Enzymes in Milk, Cork, Ireland, 20–22 April 2005.     

Mining,heterologous expression,purification, antibactericidal mechanism,and application of bacteriocins: A review

Bacteriocins are generally considered as low-molecular-weight ribosomal peptides or proteins synthesized by G⁺ and G⁻ bacteria that inhibit or kill other related or unrelated microorganisms. However, low yield is an important factor restricting the application of bacteriocins. This paper reviews mining methods, heterologous expression in different systems, the purification technologies applied to bacteriocins, and identification methods, as well as the antibacterial mechanism and applications in three different food systems. Bioinformatics improves the efficiency of bacteriocins mining. Bacteriocins can be heterologously expressed in different expression systems (e.g., Escherichia coli, Lactobacillus, and yeast). Ammonium sulfate precipitation, dialysis membrane, pH-mediated cell adsorption/desorption, solvent extraction, macroporous resin column, and chromatography are always used as purification methods for bacteriocins. The bacteriocins are identified through electrophoresis and mass spectrum. Cell envelope (e.g., cell permeabilization and pore formation) and inhibition of gene expression are common antibacterial mechanisms of bacteriocins. Bacteriocins can be added to protect meat products (e.g., beef and sausages), dairy products (e.g., cheese, milk, and yogurt), and vegetables and fruits (e.g., salad, apple juice, and soybean sprouts). The future research directions are also prospected.     

Assessing the influence of the coffee cup on the multisensory tasting experience

This review summarizes the latest evidence concerning the impact of the colour, shape, texture, weight, and other material properties of the drinking receptacle on the perception of coffee. The colour of the cup, for instance, has been shown to prime notions of sweetness (e.g., pink cup) or acidity (e.g., yellow or green cup) that may carry over to influence the tasting experience. Meanwhile, the shape and surface feel of the drinking vessel have also been shown to exert a profound influence over the perceived aroma/taste of coffee. Given that the various sensory attributes of the drinking vessel can exert such a striking influence over the drinking experience, the challenge, moving forward, is to optimize the design of the receptacle in order to enhance the multisensory tasting experience for the consumer. Given that different styles/varieties of specialty coffee have different dominant/desirable qualities (e.g., acidity/sweetness), in the future, the design of coffee cups may need to be customized for different coffee drinking experiences (e.g., origin or roast), much as seen in the world of fine wine (with different glasses for different grape varieties).     

Volatile N-nitrosamines in meat products: Potential precursors,influence of processing,and mitigation strategies

Meat products can be contaminated with carcinogenic N-nitrosamines, which is ascribed to the reaction between a nitrosating agent, originating from nitrite or smoke, and a secondary amine, derived from protein and lipid degradation. Although in model systems it is demonstrated that many amine containing compounds can be converted to N-nitrosamines, the yield is dependent of reaction conditions (e.g., low pH and high temperature). In this article, the influence of the composition of the meat products (e.g., pH, a_w, spices) and processing (e.g., ageing, ripening, fermentation, smoking, heat treatment and storage) on the presence and availability of the amine precursors and the N-nitrosamine formation mechanism is discussed. In addition, this article explores the current N-nitrosamine mitigation strategies in order to obtain healthier and more natural meat products.     

Block protocol for conventional profiling to sensory characterize plant protein isolates

Pea protein isolates are promising ingredients to use when designing new plant-based foods; have interesting functional properties (e.g., emulsification, foaming) and can serve as alternatives to animal proteins. However, their sensory properties must be considered if their use is to be optimized. Indeed, pea proteins are often perceived as having a highly persistent bitter, astringent, or beany flavor, which can strongly impact sensory assessments (e.g., carry over, sensory fatigue) during sample evaluations. Here, we proposed an explorative study for the use of an adapted sensory evaluation protocol, that could be used by trained panelists to effectively evaluate pea-protein-based foods. In short, we adapted a classical protocol - we incorporated relative-to-reference evaluation, and panelists assessed attributes in blocks rather than all at once. We conducted an experiment in which both classical and block protocols were used to evaluate pea protein solutions made with one set of isolates. Similar results were obtained with classical versus block protocol, although panelist performance (reproducibility and homogeneity) was better with block protocol. Sensitivity to bitterness was also investigated for this limited number of panelists (PROP test), and it was found that high and medium PROP tasters could better discriminate among pea protein solutions.     

Effect of a calcium-energy supplement drink at calving on lactation performance: Milk yield and composition,odds to reach a next lactation,and calving interval

Supplementation of Ca products to cows after calving is common in calving protocols. This study evaluated the effect of a Ca-energy drink voluntarily consumed on milk yield and composition, odds to reach a next lactation, and calving interval. This prospective randomized study included a blinded placebo and was conducted in 10 commercial dairy farms that included 504 Holstein dairy cows. Cows were blocked within farm by calving sequence and parity (primiparous or multiparous). Within each block of 2 animals, cows were randomly assigned to 1 of 2 treatments: a Ca-energy supplement drink (CAE, n = 255) providing 45 g of Ca and other components (dextrose, lactose, protein, fat, other minerals and vitamins), a placebo (i.e., 100 g of cellulose and 20 g of dextrose; CON, n = 249), both strictly offered to the animals for voluntary consumption. Treatments were offered mixed in 20 L of water within 3 h after calving. Milk data were analyzed using 2 approaches. The first, most classical, evaluated the effect of the treatments on observed milk data, whereas the second approach evaluated the effect on milk residuals (i.e., the difference between observed milk data and a prediction made by a herd test-day model). Eighty-one percent of the CAE cows fully consumed the treatment, whereas only 50% of CON cows did. No differences were detected for observed milk yield, nor for composition in multiparous cows. The only production effect observed on multiparous cows was a treatment by time interaction for milk fat yield, reflecting greater yield for CAE cows between 100 and 150 d in milk only. However, primiparous cows receiving CAE had increased milk (+0.8 kg/d) and component yields (i.e., +40 g/d of protein) compared with CON cows. These effects were more evident when milk and milk components residuals data were analyzed (i.e., +1.5 kg/d for milk yield and +57 g/d of protein). This was achieved with a herd test-day model that allowed milk and milk components data to be adjusted for environmental and genetic factors (i.e., farm effect, time effect, age at calving, parity, stage of lactation, breeding value). The treatment had no effect on the probability of reaching the next lactation (i.e., 72% of CAE cows had a next calving against 69% in CON). Primiparous cows receiving CAE had a longer calving interval compared with CON cows. At 400 d after the application of the treatment, 65% of CAE primiparous cows had a next calving, whereas 81% of CON primiparous cows had calved already. The supplementation of the tested oral Ca-energy solution at calving did not increase the probability to reach a next lactation for neither primiparous or multiparous, but positively influenced milk yield and milk component yields for primiparous.     

百合化学成分、药理作用及质量标志物的预测分析

为探究地理标志产品兰州百合（Lilium davidii var. unicolor）的植物化学成分,以甘肃省五个主要产区（兰州市榆中县、兰州市七里河区、定西市临洮县、定西市渭源县、临夏市永靖县）的兰州百合鳞茎为研究对象,基于超高效液相色谱串联四极杆飞行时间质谱法的非靶向代谢组学技术鉴定其植物化学成分。结果表明,在兰州百合鳞茎中初步鉴定出62种植物化学成分,包含谷胱甘肽等22种氨基酸、多肽及其衍生物,溶血磷脂酰胆碱等9种油脂和磷脂类,鼠李糖等7种糖类,阿魏酸、咖啡酸等7种酚酸类,山奈酚等4种黄酮类,核黄素、维生素C等4种天然维生素,阿魏酰腐胺等3种酚胺类,大丁苷等2种香豆素类,葫芦巴碱等2种生物碱,萜类组分松香酸和三萜皂苷类组分刺五加苷E。本研究丰富了兰州百合植物化学成分的现有数据,为兰州百合的研究与利用提供了科学依据。

     

Fabrication, functionalization, and application of electrospun biopolymer nanofibers

The use of novel nanostructured materials has attracted considerable interest in the food industry for their utilization as highly functional ingredients, high-performance packaging materials, processing aids, and food quality and safety sensors. Most previous application interest has focused on the development of nanoparticles. However, more recently, the ability to produce non-woven mats composed of nanofibers that can be used in food applications is beginning to be investigated. Electrospinning is a novel fabrication technique that can be used to produce fibers with diameters below 100 nm from (bio-) polymer solutions. These nanofibers have been shown to possess unique properties that distinguish them from non-woven fibers produced by other methods, e.g., melt-blowing. This is because first the process involved results in a high orientation of polymers within the fibers that leads to mechanically superior properties, e.g., increased tensile strengths. Second, during the spinning of the fibers from polymer solutions, the solvent is rapidly evaporated allowing the production of fibers composed of polymer blends that would typically phase separate if spun with other processes. Third, the small dimensions of the fibers lead to very high specific surface areas. Because of this the fiber properties may be greatly influenced by surface properties giving rise to fiber functionalities not found in fibers of larger sizes. For food applications, the fibers may find uses as ingredients if they are composed solely of edible polymers and GRAS ingredients, (e.g., fibers could contain functional ingredients such as nutraceuticals, antioxidants, antimicrobials, and flavors), as active packaging materials or as processing aids (e.g., catalytic reactors, membranes, filters (Lala et al., 2007), and sensors (Manesh et al., 2007; Ren et al., 2006; Sawicka et al., 2005). This review is therefore intended to introduce interested food and agricultural scientists to the concept of nano-fiber manufacturing with a particular emphasis on the use of biopolymers. We will review typical fabrication set-ups, discuss the influence of process conditions on nanofiber properties, and then review previous studies that describe the production of biopolymer-based nanofibers. Finally we briefly discuss emerging methods to further functionalize fibers and discuss potential applications in the area of food science and technology.     

Fish meal in animal feed and human exposure to persistent bioaccumulative and toxic substances

Persistent and bioaccumulative toxic substances (PBTSs) that end up in fish are health hazards and the object of fish-consumption advisories. Some of these substances are present as extraneous contaminants, e.g., man-made lipophilic pollutants such as organohalogen pollutants, and others such as monomethyl mercury can be considered naturally occurring. Omnivores (e.g., poultry and swine) and especially ruminants that are fed contaminated fish meal can pass monomethyl mercury and organohalogen pollutants to eggs, meat, and dairy products. Differences in fish meal PBTS profiles and farm animal (e.g., poultry, swine, cattle, and farmed fish) physiology modulate PBTSs in animal products. Fish-consumption advisories issued to protect human health do not extend to fish by-products fed to farmed animals. Animals (especially farmed fish) that are fed fish meal can bioconcentrate monomethyl mercury in protein matrices, and organohalogen pollutants can be passed on in the fat components of derived foods. Policies to decrease exposure to monomethyl mercury and organohalogen pollutants must consider farming practices that use fish by-products. A risk assessment of toxic contaminants in fish meal may indicate that food safety objectives must consider the human health impact of foods derived from animals fed contaminated meal.     

Bad company: the addition of sugar,fat, or salt reduces the perceived vitamin and mineral content of foods

The addition of disreputable ingredients (e.g., fat) can cause foods to take on perceived negative qualities (e.g., as promoters of obesity and disease) and according to recent findings, these foods can also be perceived to lack positive components (e.g., vitamins and minerals). In the present study, middle-aged and older adults were asked to rate the vitamin and mineral levels of a group of primary foods (e.g., strawberries) as well as their counterparts, i.e., a second group of similar foods (e.g., strawberries with sugar on top) that contained disreputable ingredients. The results indicate that many Americans (regardless of whether or not they have tendencies toward eating restraint) believe that fat, sugar, and salt deplete foods of vitamins and minerals. Apparently, the vilification of certain nutrients in foods (e.g., fat) by health media and the food industry influences our perceptions of the amounts of other nutrients in those same foods. These results suggest that more care and caution should be used when disseminating nutritional information.     

Hydroxy-PCBs, PBDEs, and HBCDDs in serum from an elderly population of Swedish fishermen's wives and associations with bone density

Lack of human exposure data is frequently reported as a critical gap in risk assessments of environmental pollutants, especially regarding "new" pollutants. The objectives of this study were to assess serum levels of the persistent 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), hydroxylated polychlorinated biphenyl metabolites (OH-PCBs), polybrominated diphenyl ethers (PBDEs), and hexabromocyclodode-canes (HBCDDs) in a group of Swedish middle-aged and elderly women expected to be relatively highly exposed, and to evaluate the impact of potential determinants (e.g., fish intake, age) for the inter-individual variation, as well as to investigate the association between these pollutants and bone density. No associations were found between bone mineral density or biochemical markers of bone metabolism and the analyzed environmental pollutants. Relatively high levels of CB-153 (median 260 ng/g fat) and sigma 3-OH-PCBs (median 1.7 ng/mL serum), and low concentrations of sigma6PBDEs (median 3.6 ng/g fat) were determined. Total level of HBCDDs in serum was quantified by gas chromatography with mass spectrometric detection (median 0.5 ng/g fat). HBCDD diastereomeric and enantiomeric patterns were determined by liquid chromatography with mass spectrometric detection. The dominating stereoisomer was (-)alpha-HBCDD, but 1-3% of gamma-HBCDD was also detected in the serum samples.     

Nonthermal technologies affecting techno-functional properties of edible insect-derived proteins,lipids, and chitin: A literature review

To increase the acceptability of edible insects, different strategies have been suggested to dispel neophobia toward this novel food. Extracts of the main nutritional components of insects have been proposed as food ingredients. However, extraction methods can affect the techno-functional properties of insect extracts, especially when heat is applied. Therefore, nonthermal technologies have recently attracted the attention of researchers. Among nonthermal technologies, high hydrostatic pressure (HHP), pulsed electric field (PEF), ultrasound (US) and cold atmospheric plasma (CAPP) have been described and discussed in the current review considering their effect on techno-functional properties of proteins, lipids, and chitin in insect-derived products. HHP and PEF have demonstrated great potential to improve insect protein solubility, whereas the oil holding capacity (OHC) was positively affected by PEF. The water holding capacity (WHC) showed a different performance according to insect species (Gryllodes sigillatus, Acheta domesticus, or Tenebrio molitor) and treatment applied (e.g., HHP). Of note, greater foaming capacity of insect proteins was achieved by applying HHP and US. Regarding insect lipids US assisted extraction with ethanol:water (E:W) extraction, fats rich in unsaturated fatty acids (e.g., linoleic acid) were obtained, whereas, regarding insect chitin, further studies are necessary to clearly understand and improve its extractability.     

Symposium review: Structure-function relationships in cheese

The quality and commercial value of cheese are primarily determined by its physico-chemical properties (e.g., melt, stretch, flow, and color), specific sensory attributes (e.g., flavor, texture, and mouthfeel), usage characteristics (e.g., convenience), and nutritional properties (e.g., nutrient profile, bioavailability, and digestibility). Many of these functionalities are determined by cheese structure, requiring an appropriate understanding of the relationships between structure and functionality to design bespoke functionalities. This review provides an overview of a broad range of functional properties of cheese and how they are influenced by the structural organization of cheese components and their interactions, as well as how they are influenced by environmental factors (e.g., pH and temperature).     

Characterization of major and trace minerals,fatty acid composition,and cholesterol content of Protected Designation of Origin cheeses

Cheese provides essential nutrients for human nutrition and health, such as minerals and fatty acids (FA). Its composition varies according to milk origin (e.g., species and breed), rearing conditions (e.g., feeding and management), and cheese-making technology (e.g., coagulation process, addition of salt, ripening period). In recent years, cheese production has increased worldwide. Italy is one of the main producers and exporters of cheese. This study aimed to describe mineral, FA, and cholesterol content of 133 samples from 18 commercial cheeses from 4 dairy species (buffalo, cow, goat, and sheep) and from 3 classes of moisture content (hard, <35% moisture; semi-hard, 35–45%; and soft, >45%). Mineral concentrations of cheese samples were determined by inductively coupled plasma optical emission spectrometry, and FA and cholesterol contents were determined by gas chromatography. Moisture and species had a significant effect on almost all traits: the highest levels of Na, Ca, and Fe were found in cheeses made from sheep milk; the greatest level of Cu was found in cow milk cheese, the lowest amount of K was found in buffalo milk cheese, and the lowest amount of Zn was found in goat cheeses. In all samples, Cr and Pb were not detected (below the level of detection). In general, total fat, protein, and minerals significantly increased when the moisture decreased. Buffalo and goat cheeses had the highest saturated FA content, and sheep cheeses showed the highest content of unsaturated and polyunsaturated FA, conjugated linoleic acid, and n-3 FA. Goat and sheep cheeses achieved higher proportions of minor FA than did cow and buffalo cheeses. Buffalo cheese exhibited the lowest cholesterol level. Our results confirm that cheese mineral content is mainly affected by the cheese-making process, whereas FA profile mainly reflects the FA composition of the source milk. This study allowed the characterization of mineral and FA composition and cholesterol content and revealed large variability among different commercial cheeses.     

Invited review: Use of butyrate to promote gastrointestinal tract development in calves

Promotion of microbial butyrate production in the reticulorumen is a widely used method for enhancing forestomach development in calves. Additional acceleration of gastrointestinal tract (GIT) development, both the forestomach and lower parts of the GIT (e.g., abomasum, intestine, and also pancreas), can be obtained by dietary butyrate supplementation. For this purpose, different sources (e.g., butyrate salts or butyrins), forms (e.g., protected or unprotected), methods (e.g., in liquid feed or solid feed), and periods (e.g., before or after weaning) of butyrate administration can be used. The aim of this paper was to summarize the knowledge in the field of butyrate supplementation in feeds for newborn calves in practical situations, and to suggest directions of future studies. It has been repeatedly shown that supplementation of unprotected salts of butyrate (primarily sodium salt) in milk replacer (MR) stimulates the rumen, small intestine, and pancreas development in calves, with a supplementation level equating to 0.3% of dry matter being sufficient to exert the desired effect on both GIT development and growth performance. On the other hand, the effect of unprotected butyrins and protected forms of butyrate supplementation in MR has not been extensively investigated, and few studies have documented the effect of butyrate addition into whole milk (WM), with those available focusing mainly on the growth performance of animals. Protected butyrate supplementation at a low level (0.3% of protected product in DM) in solid feed was shown to have a potential to enhance GIT development and performance of calves fed MR during the preweaning period. Justification of this form of butyrate supplementation in solid feed when calves are fed WM or after weaning needs to be documented. After weaning, inclusion of unprotected butyrate salts in solid feed was shown to increase solid feed intake, but the effect on GIT development and function has not been determined in detail, and optimal levels of supplementation are also difficult to recommend based on available reports. Future studies should focus on comparing different sources (e.g., salts vs. esters), forms (e.g., protected vs. unprotected), and doses of supplemental butyrate in liquid feeds and solid feeds and their effect not only on the development of rumen, abomasum, and small intestine but also the omasum and large intestine. Furthermore, the most effective source, form, and dose of supplemental butyrate in solid feed depending on the liquid feed program (e.g., MR or WM), stage of rearing (e.g., pre- or postweaning), and solid composition (e.g., lack or presence of forage in the diet) need to be determined.     

Effects of composition and processing variables on the oxidative stability of protein-based and oil-in-water food emulsions

Because many common foods are emulsions (mayonnaise, coffee creamers, salad dressing, etc.), a better understanding of lipid oxidation mechanisms in these systems is crucial for the formulation, production, and storage of the relevant consumer products. A research body has focused on the microstructural and oxidative stability of protein-stabilized oil-in-water emulsions that are structurally similar to innovative products that have been recently developed by the food industry (e.g., non-dairy creams, vegetable fat spreads, etc.) This review presents recent findings about the factors that determine the development of lipid oxidation in emulsions where proteins constitute the stabilizing interface. Emphasis is given to “endogenous” factors, such as those of compositional (e.g., protein/lipid phases, pH, presence of transition metals) or processing (e.g., temperature, droplet size) nature. Improved knowledge of the conditions that favor the oxidative protection of protein in emulsions can lead to their optimized use as food ingredients and thereby improve the organoleptic and nutritional value of the related products.     

Does taste sensitivity matter? The effect of coffee sensory tasting information and taste sensitivity on consumer preferences

Product sensory information, an external cue, could greatly influence consumer enjoyment of hedonic products like coffee. The question is what type of sensory information, subjective (e.g., aroma, flavor and body) or objective (e.g., origin, varieties and production practices), has a higher impact on consumer product experience accounting for heterogeneous taste sensitivity. We examine this question using a between-subject experiment where participants were either given subjective, objective or no sensory information of a specialty coffee. Participants were classified as either supertasters or other tasters using the 6-n-propylthiouracil (PROP) paper strip. The results indicate that, compared to objective sensory information and no information, subjective sensory information results in a higher taste rating and a higher preference level for the coffee. More importantly, subjective information positively influences PROP supertasters’ purchase likelihood for coffee, without necessarily affecting their bitterness perception of the coffee tasted.