Nanotechnology in the food industry I: applications

Nanotechnology is a multidisciplinary science that is having a boom today, providing new products with attractive physicochemical properties for many applications. In agri/feed/food sector, nanotechnology offers great opportunities for obtaining products and innovative applications for agriculture and livestock, water treatment and the production, processing, storage and packaging of food. To this end, a wide variety of nanomaterials, ranging from metals and inorganic metal oxides to organic nanomaterials carrying bioactive ingredients are applied. This review shows an overview of current and future applications of nanotechnology in the food industry. Food additives and materials in contact with food are now the main applications, while it is expected that in the future are in the field of nano-encapsulated and nanocomposites in applications as novel foods, additives, biocides, pesticides and materials food contact.

Sensitive and specific detection of viable Mycobacterium avium subsp. paratuberculosis in raw milk by the Peptide-mediated magnetic separation (PMS)-phage assay

This study describes further validation of a previously described Peptide-mediated magnetic separation (PMS)-Phage assay, and its application to test raw cows’ milk for presence of viable Mycobacterium avium subsp. paratuberculosis (MAP). The inclusivity and exclusivity of the PMS-phage assay were initially assessed, before the 50% limit of detection (LOD50) was determined and compared with those of PMS-qPCR (targeting both IS900 and f57) and PMS-culture. These methods were then applied in parallel to test 146 individual milk samples and 22 bulk tank milk samples from Johne’s affected herds. Viable MAP were detected by the PMS-phage assay in 31 (21.2%) of 146 individual milk samples (mean plaque count of 228.1 PFU/50 ml, range 6-948 PFU/50 ml), and 13 (59.1%) of 22 bulk tank milks (mean plaque count of 136.83 PFU/50 ml, range 18-695 PFU/50 ml). In contrast, only 7 (9.1%) of 77 individual milks and 10 (45.4%) of 22 bulk tank milks tested PMS-qPCR positive, and 17 (11.6%) of 146 individual milks and 11 (50%) of 22 bulk tank milks tested PMS-culture positive. The mean 50% limits of detection (LOD50) of the PMS-phage, PMS-IS900 qPCR and PMS-f57 qPCR assays, determined by testing MAP-spiked milk, were 0.93, 135.63 and 297.35 MAP CFU/50 ml milk, respectively. Collectively, these results demonstrate that, in our laboratory, the PMS-phage assay is a sensitive and specific method to quickly detect the presence of viable MAP cells in milk. However, due to its complicated, multi-step nature, the method would not be a suitable MAP screening method for the dairy industry.

Big Data Analysis in Social Networks : Extracting Food Preferences of Vegans from Twitter

Market research is often conducted through conventional methods such as surveys, focus groups and interviews. But the drawbacks of these methods are that they can be costly and timeconsuming. This study develops a new method, based on a combination of standard techniques like sentiment analysis and normalisation, to conduct market research in a manner that is free and quick. The method can be used in many application-areas, but this study focuses mainly on the veganism market to identify vegan food preferences in the form of a profile. Several food words are identified, along with their distribution between positive and negative sentiments in the profile. Surprisingly, non-vegan foods such as cheese, cake, milk, pizza and chicken dominate the profile, indicating that there is a significant market for vegan-suitable alternatives for such foods. Meanwhile, vegan-suitable foods such as coconut, potato, blueberries, kale and tofu also make strong appearances in the profile. Validation is performed by using the method on Volkswagen vehicle data to identify positive and negative sentiment across five car models. Some results were found to be consistent with sales figures and expert reviews, while others were inconsistent. The reliability of the method is therefore questionable, so the results should be used with caution.

Physicochemical characterisation of protein ingredients prepared from milk by ultrafiltration or microfiltration for application in formulated nutritional products

Formulated food systems are becoming more sophisticated as demand grows for the design of structural and nutritional profiles targeted at increasingly specific demographics. Milk protein is an important bio- and techno-functional component of such formulations, which include infant formula, sports supplements, clinical beverages and elderly nutrition products. This thesis outlines research into ingredients that are key to the development of these products, namely milk protein concentrate (MPC), milk protein isolate (MPI), micellar casein concentrate (MCC), β-casein concentrate (BCC) and serum protein concentrate (SPC). MPC powders ranging from 37 to 90% protein (solids basis) were studied for properties of relevance to handling and storage of powders, powder solubilisation and thermal processing of reconstituted MPCs. MPC powders with ≥80% protein were found to have very poor flowability and high compressibility; in addition, these high-protein MPCs exhibited poor wetting and dispersion characteristics during rehydration in water. Heat stability studies on unconcentrated (3.5%, 140°C) and concentrated (8.5%, 120°C) MPC suspensions, showed that suspensions prepared from high-protein MPCs coagulated much more rapidly than lower protein MPCs. β-casein ingredients were developed using membrane processing. Enrichment of β-casein from skim milk was performed at laboratory-scale using ‘cold’ microfiltration (MF) at <4°C with either 1000 kDa molecular weight cut-off or 0.1 µm pore-size membranes. At pilot-scale, a second ‘warm’ MF step at 26°C was incorporated for selective purification of micellised β-casein from whey proteins; using this approach, BCCs with β-casein purity of up to 80% (protein basis) were prepared, with the whey protein purity of the SPC co-product reaching ~90%. The BCC ingredient could prevent supersaturated solutions of calcium phosphate (CaP) from precipitating, although the amorphous CaP formed created large micelles that were less thermo-reversible than those in CaP-free systems. Another co-product of BCC manufacture, MCC powder, was shown to have superior rehydration characteristics compared to traditional MCCs. The findings presented in this thesis constitute a significant advance in the research of milk protein ingredients, in terms of optimising their preparation by membrane filtration, preventing their destabilisation during processing and facilitating their effective incorporation into nutritional formulations designed for consumers of a specific age, lifestyle or health status

Encapsulation of ascorbic acid promotes the reduction of Maillard reaction products in UHT milk

The presence of amino groups and carbonyls renders fortified milk with ascorbic acid particularly susceptible to the reduction of available lysine and to the formation of Maillard reaction products (MRPs), as Nε-(Carboxyethyl)-L-lysine (CEL), Nε-(Carboxymethyl)-L-lysine (CML), Amadori products (APs) and off-flavors. A novel approach was proposed to control the Maillard reaction (MR) in fortified milk: ascorbic acid was encapsulated in a lipid coating and the effects were tested after a lab scale UHT treatment. Encapsulation promoted a delayed release of ascorbic acid and a reduction in the formation of MRPs. Total lysine increased up to 45% in milk with encapsulated ascorbic acid, while reductions in CML, CEL and furosine ranged from 10% to 53% compared with control samples. The effects were also investigated towards the formation of amide-AGEs (advanced glycation end products) by high resolution mass spectrometry (HRMS) revealing that several mechanisms coincide with the MR in the presence of ascorbic acid (AA).

Evolution of protein bound Maillard reaction end-products and free Amadori compounds in low lactose milk in presence of fructosamine oxidase I

Thermal treatments and storage influence milk quality, particularly in low lactose milk as the higher concentration of reducing sugars can lead to the increased formation of the Maillard reaction products (MRPs). The control of the Amadori products (APs) formation is the key step to mitigate the Maillard reaction (MR) in milk. The use of fructosamine oxidases, (Faox) provided promising results. In this paper, the effects of Faox I were evaluated by monitoring the concentration of free and bound MRPs in low lactose milk during shelf life. Results showed that the enzyme reduced the formation of protein-bound MRPs down to 79% after six days at 37 °C. Faox I lowered the glycation of almost all the free amino acids resulting effective on basic and polar amino acids. Data here reported corroborate previous findings on the potentiality of Faox enzymes in controlling the early stage of the MR in foods.

A study of fish ice cream formulation by use of silver carp proteins instead of milk proteins

Fish is a valuable nutritional source witch use of it in daily meal has a beneficial role on nutritional needs supply and also causes mental and physical health especially in people who have protein and food deficiencies. Unfortunately, per capita consumption of sea foods in Iran is 5.5Kg witch is very lower than world standards. So, study on fish ice cream formulation, by use of fish protein concentrate (FPC) instead of milk protein, had done to make variation in sea foods products and also increase per capita consumption of these kinds of foods. FPC has very high protein concentration and a lot of necessary Also it's protein is very digestible amino acids like lysine and methionine with highly biological value and it's PER in compare with casein PER is high. At first fish protein concentrate type A produced from silver carp in three steps by the extraction with isopropyl alcohol solvent and heat. Microbiological and physicochemical specifications of produced FPC by rules of FDA and FAO were accepted. Finally according to panel test results, substitution of 30 percent of milk with FPC is acceptable. Also microbiological and physicochemical specifications of product were tested and results in compare with national standards of Iran were accepted.

Dynamic mental representations of habitual behaviours: Food choice on a web-based environment

Aim: Rather than being rigid, habitual behaviours may be determined by dynamic mental representations that can adapt to context changes. This adaptive potential may result from particular conditions dependent on the interaction between two sources of mental constructs activation: perceived context applicability and cognitive accessibility . Method: T wo web-shopping simulations of fering the choice between habitually chosen and non-habitually chosen food products were presented to participants. This considered two choice contexts dif fering in the habitual behaviour perceived applicability (low vs. high) and a measure of habitual behaviour chronicity . Results: Study 1 demonstrated a perceived applicability ef fect, with more habitual (non-organic) than non-habitual (organic) food products chosen in a high perceived applicability (familiar) than in a low perceived applicability (new) context. The adaptive potential of habitual behaviour was evident in the habitual products choice consistency across three successive choices, despite the decrease in perceived applicability . Study 2 evidenced the adaptive potential in strong habitual behaviour participants – high chronic accessibility – who chose a habitual product (milk) more than a non-habitual product (orange juice), even when perceived applicability was reduced (new context). Conclusion: Results portray consumers as adaptive decision makers that can flexibly cope with changes in their (inner and outer) choice contexts.

MICROBIOLOGICAL ANALYSIS OF TRADITIONALLY FERMENTED MILK SOLD IN KINIGI SECTOR OF MUSANZE DISTRICT IN RWANDA

A research work entitled: “Microbiological analysis of traditionally fermented milk (Ikivuguto) sold in Kinigi Sector of Musanze District,” was carried out at Higher Learning Institution of Applied Sciences (INES-Ruhengeri) Laboratory of Microbiology located near Volcanoes in the Northern Province of Rwanda. The main objective of this work was to determine the microbiological quality of traditionally fermented milk, which is consumed by Kinigi Center local people. The hypothesis was to analyze if traditionally fermented milk commercialized in Kinigi restaurants contained pathogenic bacteria such as fecal coliforms and Escherichia coli , in addition to staphylococci and yeasts. Milk samples were collected from Kinigi sector and examined in the microbiology laboratory in order to assess the microbiological quality and safety of traditionally fermented milk in rural areas. The samples were analyzed qualitatively and quantitatively for the microbes found in fermented milk sold in Kinigi Center, and the results were as follows: 7.21x107 CFU/ml for total counts; 3.89x107 CFU/ml for Lactobacillus ; 2.77x107 CFU/ml for yeasts; 1.196x105 CFU/ml for total coliforms; 9.63x104 CFU/ml for fecal coliforms and 8.92x103 CFU/ml for staphylococci. Biochemical tests were carried out and the results showed that identified pathogens were E. coli, Providencia alcalifaciens , and the staphylococci group. It was found that fermented milk contained genera and species of Staphylococcus haemolyticus , Staphylococcus aureus , Staphylococcus intermedius , Staphylococcus xylosus and Staphylococcus saprophyticus . Findings showed that the commercial milk samples were cross-contaminated by different pathogens from environment. These contaminations could have been due to improper handling, presence of flies, soil erosion, dust from atmosphere, as well as contaminated milk vessels or pots, stirrers and unpasteurized water. It was concluded that local farmers and milk retailers did not adhere to required hygienic conditions for milk safety. In this regard, the sold traditional fermented milk does not meet health and safety standards because people did not respect good manufacturing practices. The hypothesis and main objective were confirmed, because traditionally fermented milk of Kinigi was cross-contaminated before consumption. Thus, it would be better to train farmers in the areas of product hygiene, sanitation and safety during milking, processing and marketing.

Traditional part-time grazing: a more sustainable sheep milk and cheese production in the Basque Country

[EN] The concept of sustainability when referring to food production rests, in general, on 3 main aspects: 1) respect for the environment; 2) economic and social benefits for all involved in production; and 3) production of sufficient quantity of quality food at an accessible price. In this contribution we focus on the main aspects of the traditional sheep's milk and cheese production (under the Denomination of Origin Idiazabal Cheese) in the Basque Country that contribute primarily to its sustainability. It is based on the local latxa or carranzana breeds of sheep, adapted to the mountainous terrain. The sheepherder takes advantage of local resources to reduce management costs by combining indoor dry forage and concentrates with outdoor grazing throughout lactation, according to local pasture availability, and thus avoiding having to buy large amounts of feed. This system facilitates recycling of manure, fertilising pastures and forest at the same time. Use of local breeds helps maintain biodiversity of sheep breeds. Cheese is produced industrially (44.5% of the total cheese produced in 2008) from milk of many flocks, or artisanally (38.3%) by the sheepherders with the milk from their own flocks. Transforming their own milk into cheese is advantageous for the following reasons: 1) higher economic returns as compared to selling the milk to cheese factories because cheese price directly sold to consumers is more competitive than industrial cheese sold in supermarkets; 2) increases the value of women's work (over 80% of the cheese makers are women) in the community and their self-esteem; 3) it creates rural jobs and contributes to rural development; 4) we have demonstrated both with experimental and commercial flocks that part-time grazing allows the sheepherder to obtain high yields of milk, and cheese, of high nutritional and functional quality. Currently a less sustainable, intensive sheep's milk production with foreign, imported breeds kept indoors constantly is gaining favour among milk producers because of its perceived higher economic profitability.

Food consumption and risk of malnutrition in community-dwelling very old Spanish adults (≥ 80 years)

Introduction: There are few studies assessing overall diet and food patterns of the oldest population. Objectives: To examine food groups consumption (grams and servings) and their compliance with the dietary guidelines in community-dwelling very old Spanish adults. The relationship with the risk of malnutrition was also studied. Methods: Within the cross-sectional health study of elderly people of Villanueva de la Cañada (Madrid, Spain), in 98 non-institutionalized elders aged ≥ 80 years (66% women) food consumption was calculated from a 24-hour dietary recall and nutritional risk was assessed by Mini Nutritional Assessment (MNA). Statistical significance was evaluated at 95% confidence level (p < 0.05). Results: Men consumed significantly higher amounts of snacks/pickles and alcoholic beverages. The consumption of cereals/grain products (2 servings/day), vegetables (1.5 servings/day) and meat, fish, eggs (1.4 servings/day), was below desirable levels. As nutritional status got worse, fruit consumption was significantly smaller (p = 0.039). Relatively weak but highly significant correlations were found between MNA and oils/fats, fruits and alcoholic beverages. After adjustment for energy intake, oils and fats and fruits associations disappeared whereas a negative association between milk/dairy products and MNA was found. Conclusions: Dietary patterns of the elderly population of Villanueva are departing from the traditional Mediterranean diet and though adequate consumption of fruits, milk/dairy products, oils/fats and sugar/confectionery has been achieved, cereals/grain products, vegetables and the meat,fish,eggs group consumption was below the desirable levels. Deterioration of the nutritional status coincided with a reduction in the consumption of all food groups except for ready meals and milk/dairy products whose consumption increased. Further research on the influence of fruit, milk/dairy products, wine and olive oil consumption on nutritional status is required.

Evaluation of physicochemical and glycaemic properties of commercial plant-based milk substitutes

The market for plant-based dairy-type products is growing as consumers replace bovine milk in their diet, for medical reasons or as a lifestyle choice. A screening of 17 different commercial plant-based milk substitutes based on different cereals, nuts and legumes was performed, including the evaluation of physicochemical and glycaemic properties. Half of the analysed samples had low or no protein contents (<0.5 %). Only samples based on soya showed considerable high protein contents, matching the value of cow’s milk (3.7 %). An in-vitro method was used to predict the glycaemic index. In general, the glycaemic index values ranged from 47 for bovine milk to 64 (almond-based) and up to 100 for rice-based samples. Most of the plant-based milk substitutes were highly unstable with separation rates up to 54.39 %/h. This study demonstrated that nutritional and physicochemical properties of plant-based milk substitutes are strongly dependent on the plant source, processing and fortification. Most products showed low nutritional qualities. Therefore, consumer awareness is important when plant-based milk substitutes are used as an alternative to cow’s milk in the diet.

Applying Least Absolute Shrinkage Selection Operator and Akaike Information Criterion Analysis to Find the Best Multiple Linear Regression Models between Climate Indices and Components of Cow’s Milk

This study focuses on multiple linear regression models relating six climate indices (temperature humidity THI, environmental stress ESI, equivalent temperature index ETI, heat load HLI, modified HLI (HLI new), and respiratory rate predictor RRP) with three main components of cow’s milk (yield, fat, and protein) for cows in Iran. The least absolute shrinkage selection operator (LASSO) and the Akaike information criterion (AIC) techniques are applied to select the best model for milk predictands with the smallest number of climate predictors. Uncertainty estimation is employed by applying bootstrapping through resampling. Cross validation is used to avoid over-fitting. Climatic parameters are calculated from the NASA-MERRA global atmospheric reanalysis. Milk data for the months from April to September, 2002 to 2010 are used. The best linear regression models are found in spring between milk yield as the predictand and THI, ESI, ETI, HLI, and RRP as predictors with p-value < 0.001 and R2 (0.50, 0.49) respectively. In summer, milk yield with independent variables of THI, ETI, and ESI show the highest relation (p-value < 0.001) with R2 (0.69). For fat and protein the results are only marginal. This method is suggested for the impact studies of climate variability/change on agriculture and food science fields when short-time series or data with large uncertainty are available.