Fat concentration and high-pressure homogenization affect chlorogenic acid bioaccessibility and \u3b1-glucosidase inhibitory capacity of milk-based coffee beverages

This study aimed at investigating the effect of coffee formulation and high-pressure homogenization (HPH) on chlorogenic acid bioaccessibility and alpha-glucosidase inhibition. Coffee was added with milk (1:1) containing 0.1, 3.6 or 7.1% fat, homogenized at increasing pressure (0-150 MPa) and in vitro digested. Using milk with the highest fat concentration (7.1%) promoted the formation of smaller particles after HPH treatment, as well as upon digestion. Digested samples with the highest fat content also presented lower zeta-potential, suggesting higher stability. Chlorogenic acids (CGAs) bioaccessibility and alpha-glucosidase inhibition were evaluated upon in vitro digestion. CGAs bioaccessibility increased from nearly 25% to > 50% by adding milk and using HPH. These could promote CGAs micellarization, reducing their susceptibility to degradation during digestion. Properly combined milk and HPH also improved alpha-glucosidase inhibitory effect. No correlation was found between CGAs bioaccessibility and alpha-glucosidase inhibition, suggesting that other components may govern antidiabetic properties of coffee

Use of time-resolved fluorescence to monitor bioactive compounds in plant based foodstuffs

The study of compounds that exhibit antioxidant activity has recently received much interest in the food industry because of their potential health benefits. Most of these compounds are plant based, such as polyphenolics and carotenoids, and there is a need to monitor them from the field through processing and into the body. Ideally, a monitoring technique should be non-invasive with the potential for remote capabilities. The application of the phenomenon of fluorescence has proved to be well suited, as many plant associated compounds exhibit fluorescence. The photophysical behaviour of fluorescent molecules is also highly dependent on their microenvironment, making them suitable probes to monitor changes in pH, viscosity and polarity, for example. Time-resolved fluorescence techniques have recently come to the fore, as they offer the ability to obtain more information, coupled with the fact that the fluorescence lifetime is an absolute measure, while steady state just provides relative and average information. In this work, we will present illustrative time-resolved measurements, rather than a comprehensive review, to show the potential of time-resolved fluorescence applied to the study of bioactive substances. The aim is to help assess if any changes occur in their form, going from extraction via storage and cooking to the interaction with serum albumin, a principal blood transport protein

Furan and 5-hydroxymethylfurfural removal from high- and low-moisture foods

Foods with different moisture and fat contents (i.e. meat sauce and biscuits) were subjected to treatments at 4, 12 and 19 kPa for increasing lengths of time to remove furan and 5-hydroxymethylfurfural (HMF). The vacuum treatments were ineffective in removing HMF from both food types, as well as furan from the biscuits, unless this food was preliminary hydrated at high water activity. However, the vacuum treatments allowed furan to be removed from the high moisture food. In particular, 67% furan removal from the meat sauce was achieved by applying 12 kPa for 10 min. Sensory analysis results showed that meat sauce subjected to such a treatment presented the same odor intensity of the untreated sample. The post-process vacuum treatment could represent a reliable strategy to mitigate the furan levels in high moisture foods

Reducing the glycemic index of short dough biscuits by using apple pomace as a functional ingredient

The present research aimed at enriching short dough biscuits with apple pomace to reduce their glycemic index. Apple pomace produced on a laboratory scale was dehydrated and milled to a powder, which was characterized for soluble and insoluble dietary fiber, and for phenolic content. Apple pomace was used to partially replace wheat flour (10 and 20% w/w) in biscuits, which were characterized for their sensory properties and submitted to in vitro digestion to predict the glycemic index. Results indicated that apple pomace contained impressive amounts of dietary fiber (nearly 40%), mainly represented by insoluble fiber (more than 25%). Apple pomace led to a significant reduction in the expected glycemic index of reformulated biscuits. The conventional biscuit presented a glycemic index of 70 and was thus classified as high glycemic index food. Substituting wheat flour by 10 and 20% with apple pomace reduced biscuit glycemic index to 65 and 60 respectively, thus ranking the product within the intermediate glycemic index foods. Using industrial apple pomace led to analogous results, demonstrating that this by-product could be exploited to reduce the glycemic index of bakery foods, thus concomitantly satisfying the need for strategies to manage type 2 diabetes and to valorize food by-products

Effect of continuous cooking on cooking water properties and pasta quality

BACKGROUND Professional pasta cookers are filled with fresh water. The solids leached from the cooked pasta make pasta less firm and stickier while leading to changes in water properties and overflow. Added fresh water then has to be reheated. The effect of continuous cooking on cooked pasta quality and water properties was investigated for the first time by simulating professional pasta cooking on a laboratory scale. RESULTS Continuous cooking procedure of 12 batches led to a solid content of cooking water of 37gkg(-1), resulting in an increase in shear-thinning behaviour and consistency index. Pasta cooking loss decreased from 52.7 to 35.7gkg(-1) due to the lower water concentration gradient through the pasta. This was confirmed by a decrease in swelling index from 2.0x10(-3) to 1.6x10(-3)gkg(-1) during the optimal cooking time (13min 45s). Surprisingly, continuous cooking made the pasta firmer while stickiness did not differ significantly (P>0.05). CONCLUSION Taking batch number 7 as the acceptability threshold, further studies are required to find an optimal solution for retaining cooking water properties highly affecting daily cooking procedures in food service kitchens. (c) 2018 Society of Chemical Industr

Effect of pasteurization on in vitro \u3b1-glucosidase inhibitory activity of apple juice

The in vitro alpha-glucosidase inhibitory activity of raw, mildly (F-71.7(5) = 0.4 min, 5 Log reductions of Cryptosporidium parvum) and intensively (F-90(12) = 14.8 min, 2 Log reductions of Alicyclobacillus acidoterrestris) pasteurized apple juice was studied. Raw apple juice (23 mg(dw)/mL) caused 90% alpha-glucosidase inhibition. Analogous results were obtained for the mildly treated sample. The most intense treatment reduced by 35% the alpha-glucosidase inhibition. However, such a decrease was associated with an increase in the phenolic content, suggesting that alpha-glucosidase inhibition might not rely on these compounds, but depend on more complex mechanisms. Apple juice was combined with acarbose to investigate their interaction towards alpha-glucosidase inhibition. A synergistic behavior was observed for concentrations < 2 mg/mL. Increasing the concentration of the combined system (up to 9 mg/mL) produced an antagonistic effect, while a further increase (< 9 mg/mL) allowed approaching an addictive behavior

Combined high-power ultrasound and high-pressure homogenization nanoemulsification: The effect of energy density, oil content and emulsifier type and content

Combinations of ultrasound (US) and high-pressure homogenization (HPH) at low-medium energy densities were studied as alternative processes to individual US and HPH to produce Tween 80 and whey protein stabilized nanoemulsions, while reducing the energy input. To this aim, preliminary trials were performed to compare emulsification efficacy of single and combined HPH and US treatments delivering low-medium energy densities. Results highlighted the efficacy of US-HPH combined process in reducing the energy required to produce nanoemulsions stabilized with both Tween 80 and whey protein isolate. Subsequently, the effect of emulsifier content (1-3% w/w), oil amount (10-20% w/w) and energy density (47-175 MJ/m(3)) on emulsion mean particle diameter was evaluated by means of a central composite design. Particles of 140-190 nm were obtained by delivering 175 MJ/m(3) energy density at emulsions containing 3% (w/w) Tween 80 and 10% (w/w) oil. In the case of whey protein isolate stabilized emulsions, a reduced emulsifier amount (1% w/w) and intermediate energy density (120 MJ/m(3)) allowed a minimum droplet size around 220-250 nm to be achieved. Results showed that, in both cases, at least 50% of the energy density should be delivered by HPH to obtain the minimum particle diameter.Peer reviewe

Shelf-life Assessment of Food Undergoing Oxidation\u2013A Review

Oxidation is the most common event leading to the end of shelf life of microbiologically stable foods. Thus, a reliable shelf-life assessment is crucial to verify how long the product will last before it becomes oxidized to an unacceptable level to the consumers. Shelf-life assessment strategies of foods and beverages suffering oxidation are critically discussed focusing on definition of the acceptability limit, as well as the choice of the proper oxidative indicators, and methodologies for shelf-life testing. Testing methodologies for shelf-life determination under actual and accelerated storage conditions are considered, highlighting possible uncertainties, pitfalls, and future research needs. \ua9 2016, Copyright \ua9 Taylor & Francis Group, LLC

Effect of ultrasound treatment, oil addition and storage time on lycopene stability and in vitro bioaccessibility of tomato pulp

This study was performed to investigate the influence of ultrasound processing on tomato pulp containing no sunflower oil, or increasing amounts (i.e. 2.5%, 5% and 10%), on lycopene concentration and in vitro bioaccessibility at time zero and during storage at 5 \ub0C. Results confirmed previous findings in that ultrasonication was responsible for cell breakage and subsequent lycopene release in a highly viscous matrix. Neither the ultrasound process nor oil addition affected lycopene concentration. A decrease of approximately 35% lycopene content occurred at storage times longer than 15 days, due to isomerisation and oxidation reactions. No differences in lycopene in vitro bioaccessibility were found between the untreated and ultrasonically treated samples; this parameter decreased as a consequence of oil addition. Losses of lycopene in vitro bioaccessibility ranging between 50% and 80% occurred in the untreated and ultrasonically treated tomato pulps with and without oil during storage, mainly due to carotenoid degradation

Use of time-resolved spectroscopy as a method to monitor carotenoids present in tomato extract obtained using ultrasound treatment

Introduction Compounds exhibiting antioxidant activity have received much interest in the food industry because of their potential health benefits. Carotenoids such as lycopene, which in the human diet mainly derives from tomatoes (Solanum lycopersicum), have attracted much attention in this aspect and the study of their extraction, processing and storage procedures is of importance. Optical techniques potentially offer advantageous non-invasive and specific methods to monitor them. Objectives To obtain both fluorescence and Raman information to ascertain if ultrasound assisted extraction from tomato pulp has a detrimental effect on lycopene. Method Use of time-resolved fluorescence spectroscopy to monitor carotenoids in a hexane extract obtained from tomato pulp with application of ultrasound treatment (583 kHz). The resultant spectra were a combination of scattering and fluorescence. Because of their different timescales, decay associated spectra could be used to separate fluorescence and Raman information. This simultaneous acquisition of two complementary techniques was coupled with a very high time-resolution fluorescence lifetime measurement of the lycopene. Results Spectroscopic data showed the presence of phytofluene and chlorophyll in addition to lycopene in the tomato extract. The time-resolved spectral measurement containing both fluorescence and Raman data, coupled with high resolution time-resolved measurements, where a lifetime of ~5 ps was attributed to lycopene, indicated lycopene appeared unaltered by ultrasound treatment. Detrimental changes were, however, observed in both chlorophyll and phytofluene contributions. Conclusion Extracted lycopene appeared unaffected by ultrasound treatment, while other constituents (chlorophyll and phytofluene) were degraded. Copyright \ua9 2015 John Wiley & Sons, Ltd