Experimental design for fermentation media development: statistical design or global random search?

The diversity of combinatorial interactions of medium components with the metabolism of cells as well as the large number of medium constituents necessary for cellular growth and production do not permit satisfactory detailed modelling. For this reason, experimental search procedures in simultaneous shaking flask experiments are used to optimise fermentation media. As an alternative to the methods of statistical experimental design employed in this field for many decades, the use of stochastic search procedures has been evaluated recently, since these require neither the unimodality of the response surface nor limitations in the number of medium components under consideration. Genetic algorithms were selected due to their basic capability for efficient exploration of large variable spaces. Using a genetic algorithm, it has been experimentally verified, with the aid of process examples, that process improvements can be achieved both for microbial and enzymatic conversions and for cell cultures despite the large number of medium components under simultaneous consideration (about 10 or more). In exploring a new variable space, process improvements of more than 100% were generally achieved. For initial reaction conditions previously 'optimised' via standard procedures it has been possible in most cases to achieve a further improvement of 20-40% of the target quantity. Although the genetic algorithm can be very efficient for exploration of large variable spaces, it is improbable that a 'global optimum' can be precisely identified because of the relatively small number of shaking flask experiments usually performed. As a consequence, a combination of highly directed random searches to explore the n-dimensional variable space with the genetic algorithm and subsequent application of classical statistical experimental design is recommended for media development.     

Can umami taste be an adequate tool for reducing sodium in food preparations?

Researches indicate that the Brazilian population is still consuming sodium in excess and national epidemiological studies, have not verified the impact of taste modifications provided by the formulations available on the market and in homemade meals. The objective is to verify whether the basic umami taste, in the form of monosodium glutamate (MSG) monohydrate, is an alternative for reducing sodium in the preparation of meals. Also, to confirm the ideal concentration of MSG equivalent to acceptance with salt, and the impact of an explanatory video about warnings of salt excess on consumer behaviour, regarding the intention to use table salt in meals. For this study, three concentrations of sodium were used in the preparations rice and ground meat: one with the intrinsic sodium of the food, one with the addition of salt, 1 g for 100 g of rice and for meat, and one with salt and MSG, for 100 g of rice, 0.54% are of salt and 0.43% are of MSG and for 100 g of meat, 0.55% are of salt and 0.44% are of MSG. All quantities were suggested by a previous study, confirmed in a sensorial pre-test. The acceptability of preparations was assessed by the preference test. The levels of sodium and glutamic acid in the test preparations were also analysed. The results showed no significant difference between the exposed to the video. This study showed a sodium reduction of at least 30% in rice and 33% in ground meat, two kinds of meals widely consumed in Brazil, maintaining the same acceptance. These data suggest that the partial substitution of NaCl with MSG/umami can be an alternative to reduce sodium in meals.     

Long-term accuracy of MDF milling process—development of adaptive control system corresponding to progression of tool wear

The study describes a new adaptive control system corresponding to progression of tool wear. The idea was based on an original machine vision system used for measuring the dimensions of workpieces. It turned out that the new adaptive control system might be quite effective. A significant improvement (from IT16 to IT12) of long-term MDF milling process accuracy was observed. Moreover, it was found that direct measurement of cutting errors based on workpieces vision inspection was generally more useful than tool wear monitoring. The real cutting errors observed for MDF side milling were neither equal nor even strictly proportional to the errors which would be expected, or explainable, only on the basis of the real decrease in the diameter of end mill (the decrease being the obvious result of tool wear progression).     

What separates the winners from the losers in new food product development?

The low rate of innovation and high rate of failure of new food products is a cause for concern. Whilst a wide range of product development process factors are known to influence product success and failure, these predictors are based almost exclusively upon investigations into ‘industrial’ rather than food products. In this paper, an analysis of existing models of product development is carried out, a recently developed model for reduced fat food product development is described and implications for best practice in food product development discussed. Market and consumer knowledge and retailer involvement are key success factors in food product development.     

Understanding consumer data use in new product development and the product life cycle in European food firms – An empirical study

New food products have a high chance of market failure. To improve the chances of new product success, a consumer-oriented approach to product development has been recommended. The approach emphasizes the importance of an optimal fit between consumers’ needs and the new product. To achieve this goal, food professionals generate and use various consumer data types and methods. However, very few studies address the extent to which the food industry uses consumer data in product development. This study investigated to what extent European food firms use various consumer data in different phases, i.e., new product development (NPD) and the product life cycle (PLC), and what data collection methods they employ. The current study classified consumer data into three types: consumer involvement, food trend, and environmental factor data. The results showed that more than 85% of the respondents use all three data types in NPD, while they rarely use consumer data in the PLC. Respondents most frequently use data collection methods such as focus groups, consumer surveys, and indirect data collection (e.g., internet, magazines). These methods are less effective in assuring product success and in developing new-to-the-world products. In fact, more than half of the respondents never or rarely worked on new-to-the-world projects. Increasing the use of consumer data in the PLC and adapting data collection methods to the type of the project and the phase of product development present opportunities for food firms to improve chances of new product success.     

Can environmental dust from silo area allow the development of stored product insects?

Dust derived from food processing can accumulate in places difficult to reach, where stored-product pests could thrive. The purpose of this work was to verify the development of Plodia interpunctella, Ephestia kuehniella, and Tribolium castaneum in dust collected on pipes and beams (15 m and 7.5 m) in a silo area of a pasta industry. Proximate analyses showed a higher metal content in the dust collected at the two different heights than semolina, including the presence of chrome, cobalt, arsenic, and lead. Particle size distribution analysis showed that in the two samples of dust the highest percentage was constituted by particle sizes smaller than 106 μm. The tests were carried out by using two quantities 4 g or 0.15 g of dust (corresponding to 3 mm and 0.1 mm), at controlled conditions. Fifty larvae, 0–24 h old, of each species, were used for each dust, semolina, and thickness test. The number of emerged adults was assessed daily. T. castaneum developed on all the tested substrates, despite the high content of metals and the small particle size in the environmental dust. A significant interaction between diet and thickness of the layer was observed, but thickness had a stronger influence than diet. Moreover, light filth analysis detected a large number of fragments of Tribolium sp. in dust collected at a different height. Dust was unsuitable for the development of moths; only two E. kuehniella adults emerged from 3-mm-deep dust collected at 15 m, and development lasted more than 90 d.     

Vibration-induced particle formation during yogurt fermentation — Industrial vibration measurements and development of an experimental setup

The aim of the study was to investigate the effects of vibrations during yogurt fermentation. Machinery such as pumps and switching valves generate vibrations that may disturb the gelation by inducing large particles. Oscillation measurements on an industrial yogurt production line showed that oscillations are transferred from pumps right up to the fermentation tanks. An experimental setup (20 L) was developed to study the effect of vibrations systematically. The fermenters were decoupled with air springs to enable reference fermentations under idle conditions. A vibration exciter was used to stimulate the fermenters. Frequency sweeps (25–1005 Hz, periodic time 10 s) for 20 min from pH 5.4 induced large particles. The number of visible particles was significantly increased from 35 ± 4 (reference) to 89 ± 9 particles per 100 g yogurt. Rheological parameters of the stirred yogurt samples were not influenced by vibrations.     

Alteration of apparent viscosity of irradiated pepper — a tool for semi-quantitative estimation of irradiation dose

The feasibility of using apparent viscosity (_a) as a method for detecting the occurrence of previous irradiation of pepper was studied. Apparent viscosity of heat-treated suspensions of white and black pepper, nonirradiated or irradiated with different doses of ionising radiation (), was measured under different shear rates. Results of previous research were therefore expanded and their usefulness examined; low shear rate conditions were found to be preferable for the detection and semi-quantitative evaluation of irradiation doses. The experimental methodology for semi-quantitative estimation was developed and its scope and limitations are presented.     

The role of processing and matrix design in development and control of microstructures in dairy food production—a survey

New options to process dairy products by means of new single unit operations or combinations thereof are presented. The innovative possibilities discussed in this paper mainly refer to novel ways of influencing product microstructures or textures as perceived during consumption, by means of contributions of single molecule fractions of complex systems derived from membrane fractionation techniques. In addition, options to integrate physiologically active components which also have a structure forming effect in fermented or other dairy products are highlighted. Alternatives derived from thermal, mechanical and enzymatic processing and from fractionation techniques by means of membranes are presented which can be exploited for fractionation and compositional matrix design of dairy products.     

Using color–odor correspondences for fragrance packaging design

Fragrance companies may use colors in packaging design to communicate the properties of their fragrances. Packages with matching colors may have an additional advantage: some studies suggest that consumers prefer offerings for which all sensory impressions are congruent. Hence, we investigated whether consumers are more likely to buy fragrances with a matching package.For five fragrances we created a package, based on a harmonious combination of three colors that obtained high odor–color goodness-of fit ratings in a previous study. Packages were identical in design, except for the colors used. The appropriateness ratings for the five packages were indeed found to be related to the ratings for its major colors.Subsequently, we assessed the degree to which participants were likely to buy different fragrance–package combinations. However, buying intentions were not affected by the degree of matching between fragrance and packaging. Instead, they were typically dependent on the degree of liking for the fragrance and, to a lesser extent, on the degree of liking for the package.     

Preservation of liquid foods by high intensity pulsed electric fields—basic concepts for process design

In excess of a critical transmembrane potential Δϕ_M of −1 V produced by high intensity pulsed electric fields a rapid electrical breakdown and local conformational changes of cell membranes occur which result in a drastic increase in permeability and an equilibration of the electrochemical and electrical potential differences of the cell plasma and the extracellular medium. As irreverible membrane permeabilization impairs most vital physiological control systems, high intensity pulsed electric fields may be applied as a highly effective process for the microbial decontamination of liquid foods. The efficiency of the treatment is largely influenced by the inherent properties of the foods and of the spoiling microorganisms. In addition a number of technical limitations have to be considered. In this review an approach is presented which reduces the diversity of parameters that affect microbial inactivation during pulsed power treatment. In particular, the required total specific energy input is discussed.     

Emulsion design for the delivery of β-carotene in complex food systems

β-Carotene has been widely investigated both in the industry and academia, due to its unique bioactive attributes as an antioxidant and pro-vitamin A. Many attempts were made to design delivery systems for β-carotene to improve its dispersant state and chemical stability, and finally to enhance the functionality. Different types of oil-in-water emulsions were proved to be effective delivery systems for lipophilic bioactive ingredients, and intensive studies were performed on β-carotene emulsions in the last decade. Emulsions are thermodynamically unstable, and emulsions with intact structures are preferable in delivering β-carotene during processing and storage. β-Carotene in emulsions with smaller particle size has poor stability, and protein-type emulsifiers and additional antioxidants are effective in protecting β-carotene from degradation. Recent development in the design of protein-polyphenol conjugates has provided a novel approach to improve the stability of β-carotene emulsions. When β-carotene is consumed, its bioaccessibility is highly influenced by the digestion of lipids, and β-carotene in smaller oil droplets containing long-chain fatty acids has a higher bioaccessibility. In order to better deliver β-carotene in complex food products, some novel emulsions with tailor-made structures have been developed, e.g., multilayer emulsions, solid lipid particles, Pickering emulsions. This review summarizes the updated understanding of emulsion-based delivery systems for β-carotene, and how emulsions can be better designed to fulfill the benefits of β-carotene in functional foods.     

Which front-of-pack nutrition label is the most efficient one? The results of an eye-tracker study

Different labeling systems that should help consumers make more balanced food decisions have been proposed and are currently in use. In the present study, the effectiveness of three different formats, the nutrition table format, the guideline daily amounts (GDAs) format, and the traffic light (TL) format, was examined. The eye-tracking method was combined with an experimental approach. The participants (N = 98) were randomly assigned to one of the three formats, and they were asked to evaluate the healthiness of five foods from different food categories. The eye-tracking data suggest that the participants needed more time to process the GDA format in comparison to the traffic light format and the nutrition table format. Moreover, the participants processed the traffic light format more efficiently than the nutrition table. In regard to information processing, the traffic light format was better than the other two formats. The participants were asked how they perceived the healthiness of the food products. The GDA, the TL and the nutrition table formats did not result in substantially different evaluations of the products. From an information processing perspective, the TL format has advantages over the other two formats. The TL format is a consumer-friendly way of communicating nutrition information.     

An efficient process for co-production of γ-aminobutyric acid and probiotic Bacillus subtilis cells

Food Science and Biotechnology - This study was to establish an integrated process for the co-production of γ-aminobutyric acid (GABA) and live probiotics. Six probiotic bacteria were screened...     

Bacteriophage lysis of Enterococcus host strains: a tool for microbial source tracking?

This paper describes the isolation of Enterococcus host strains, for potential use as simple bacteriophage (phage)-based microbial source tracking (MST) tools. Presumptive Enterococcus host strains were isolated from cattle feces, raw municipal wastewater, agricultural runoff, and waters impacted by farms or wastewater treatment works (WWTW) in southern England, United Kingdom (UK). All enterococcal host strains (n = 390) were first screened for their ability to detect phage in samples of raw municipal wastewater and fecal material from cattle, pigs, and sheep. Host strains that detected phage (n = 147) were ranked according to both their specificity to a particular fecal source and also the number of phages (expressed as plaque-forming units, PFU) that they detected per milliliter of sample. Host strains that demonstrated host specificity and which detected phages at levels greater than 100 PFU/mL (n = 29) were further tested using additional fecal samples of human and nonhuman origin. The specificity and sensitivity of the enterococcal host strains were found to vary, ranging from 44 to 100% and from 17 to 83%, respectively. Most notably, seven strains exhibited 100% specificity to either cattle, human, or pig samples. Isolates exhibiting specificity to cattle were identified as belonging to the species Enterococcus casseliflavus , Enterococcus mundtii , or Enterococcus gallinarum , while human and pig isolates were members of either Enterococcus faecium or Enterococcus faecalis . The high specificity of phages infecting Enterococcus hosts and the simplicity and relatively low cost of the approach collectively indicate a strong potential for using this method as a tool in MST.