Feasibility of using colorimetric devices for whole and ground coffee roasting degrees prediction.

BACKGROUND: Coffee roasting is one of the crucial steps in obtaining a high-quality product as it forms the product's color and flavor characteristics. Roast control is made by visual inspection or traditional instruments such as the Agtron spectrophotometer, which can have high implementation costs. Therefore, the present study evaluated colorimetric approaches (a bench colorimeter, smartphone digital images, and a colorimetric sensor) to predict the Agtron roasting degrees of whole and ground coffee. Two calibration approaches were assessed, that is, multiple linear regression and least-squares support vector machine. For that, 70 samples of whole and ground roasted coffees comprising the Agtron roasting range were prepared. RESULTS: The results showed that all three colorimetric acquisition types were efficient for the model building, but the bench colorimeter and the smartphone digital images generally performed with good determination coefficients and low errors as measured by external validation. For the whole bean coffee, the best model presented a determination coefficient (R2) of 0.99 and a root-mean-squared error (RMSE) of 1.91%, while R2 of 0.99 and RMSE of 0.87% was obtained for ground coffee, both using the colorimeter. CONCLUSION: The obtained models presented good prediction capability, as assessed by external validation and randomization tests. The obtained findings point to an alternative for coffee roasting monitoring that can lead to higher digitalization and local control of the process, even for smaller producers, due to its lower costs. © 2024 Society of Chemical Industry.

Exploring Strategies to Mitigate the Lightness Effect on the Prediction of Soybean Oil Content in Blends of Olive and Avocado Oil Using Smartphone Digital Image Colorimetry.

Extra virgin olive oil (EVOO) and avocado oil (AVO) are recognized for their unique sensory characteristics and bioactive compounds. Declared blends with other vegetable oils are legal, but undeclared mixing is a common type of fraud that can affect product quality and commercialization. In this sense, this study explored strategies to mitigate the influence of lighting in order to make digital image colorimetry (DIC) using a smartphone more robust and reliable for predicting the soybean oil content in EVOO and AVO blends. Calibration models were obtained by multiple linear regression using the images' RGB values. Corrections based on illuminance and white reference were evaluated to mitigate the lightness effect and improve the method's robustness and generalization capability. Lastly, the prediction of the built model from data obtained using a distinct smartphone was assessed. The results showed models with good predictive capacities, R2 > 0.9. Generally, models solely based on GB values showed better predictive performances. The illuminance corrections and blank subtraction improved the predictions of EVOO and AVO samples, respectively, for image acquisition from distinct smartphones and lighting conditions as evaluated by external validation. It was concluded that adequate data preprocessing enables DIC using a smartphone to be a reliable method for analyzing oil blends, minimizing the effects of variability in lighting and imaging conditions and making it a potential technique for oil quality assurance.

Prebiotic potential of pulp and kernel cake from Jerivá (Syagrus romanzoffiana) and Macaúba palm fruits (Acrocomia aculeata).

The jerivá (Syagrus romanzoffiana) and the macaúba (Acrocomia aculeata) are palm trees of the Arecaceae family, widely distributed in tropical and subtropical areas of Latin America, which have a low production cost and high productivity throughout the year. Due to the high content of lipids, their fruits have been used for oil extraction, which generates byproducts such as the pulps and the kernel cakes, a nutritionally rich byproduct that can be added into human food and, may have prebiotic potential. Therefore, the objective of this work was to characterize and evaluate the prebiotic potential of jerivá pulp (JP), macaúba pulp (MP), jerivá kernel cake (JC) and macaúba kernel cake (MC). For this, the fruits characterization was carried out through proximate composition, phenolic compounds content, and antioxidant activity, besides evaluating the antimicrobial and fermentative capacity of Bifidobacterium lactis, Lactobacillus casei, and Lactobacillus acidophilus against Escherichia coli. Jerivá and macaúba pulps and kernel cakes presented high levels of dietary fiber (20.45% JP, 37.87% JC, 19.95% MP and 35.81% MC) and high antioxidant activity, especially JP, which also showed the high values found for ABTS and DPPH (2498.49 µMTrolox·g-1 fruit and 96.97 g fruit·g-1 DPPH, respectively), has a high total phenolic content (850.62 mg GAE·100 g-1). Also, JP promoted a better growth of probiotic strains and a more relevant pH reduction when compared to the commercial prebiotic FOS. However, MP, JC, and MC were also able to favor the growth of the strains. Probiotic microorganisms were able to use JP, MP, JC, and MC and produced short-chain fatty acids such as lactic, propionic, butyric, and acetic acid, capable of promoting health benefits. Therefore, the byproducts from jerivá and macaúba oil extraction have characteristics that indicate their prebiotic potential, and maybe interesting components to increase the nutritional value of foods.

Experimental techniques for the extraction of taro mucilage with enhanced emulsifier properties using chemical characterization.

The objective of this study was to analyze existing taro mucilage extraction techniques for extraction of a pure product with high emulsifying action to chemically characterize the mucilage. Five taro mucilage extraction techniques were analyzed which used room temperature, 4 °C, or 80 °C, with or without ethanol precipitation. Protein was detected in the mucilage extracted by each method and is ideal for the emulsifying action. Only mucilage extracted at low temperature and precipitated with ethanol did not contain starch, which is considered an impurity in the product. Therefore, from the tested techniques, cold extraction was found to provide mucilage with good emulsion activity and stability, making it possible to be used as a natural emulsifier. This mucilage is primarily formed by arabinogalactans connected to proteins which form AGP glycoprotein, a macro-molecule responsible for the emulsifying action.

Temporal profile of flavor enhancers MAG, MSG, GMP, and IMP, and their ability to enhance salty taste, in different reductions of sodium chloride.

We evaluated the temporal profile of the flavor enhancers monosodium glutamate (MSG), disodium inosinate (IMP), disodium guanylate (GMP), and monoammonium glutamate (MAG). We also evaluated the ability of these flavor enhancers to enhance salty taste in solutions containing different reductions of sodium chloride. Four experiments were conducted using Central Composite Rotational Design (CCRD) with focus on two objectives: concentration of flavor enhancers (0% to 1%) and reduction of sodium chloride content (0% to 100%). A 0.75% saline solution of NaCl was used as a control. In each experiment, the treatments were evaluated by the intensity of salty and umami tastes using an intensity scale. Treatments, selected according to the results of CCRD, were analyzed using time-intensity (TI) and temporal dominance of sensations (TDS) analyses. Glutamates (MSG/MAG) showed greater capacity to enhance salty taste than treatments containing nucleotides (IMP/GMP). The intensity of umami taste, using all the examined flavor enhancers, showed a similar sensory profile. Temporal perception curves (TI and TDS) of salty and umami tastes also showed a similar temporal profile. The glutamic acid amino acids were better able to improve salty taste than nucleotides in any range of sodium chloride reduction. Flavor enhancers showed greater ability to increase salty taste in smaller reductions in sodium chloride content. PRACTICAL APPLICATION: This research expand the knowledge about the ability to enhance the salty taste of flavor enhancers in different reductions in sodium content, Beside that, will provide information about the time profile of flavor enhancers. This study provides scientific technical information on the ability to intensify the salty taste of flavor enhancers and can assist the industry to develop new low sodium products and encourage the scientific community to conduct future research on this subject.

The chemical, thermal and textural characterization of fractions from Macauba kernel oil.

Macauba (Acrocomia aculeata) kernel oil is rich in short- and medium-chain saturated and unsaturated fatty acids, the most abundant of which are lauric and oleic acids. The oil also has high oxidative stability and contains bioactive compounds. Like other oils rich in lauric acid, Macauba kernel oil is solid at low temperatures but has a low solid fat content at room temperature. The hypothesis of this study is that the thermal and textural characteristics of Macauba kernel oil can be modified by fractionation. Fractions were obtained and analysed with respect to their fatty acid profile, oxidative stability, crystallization and melting profile, firmness and physical state at different temperatures. The fatty acid profiles of the fractions remained virtually unchanged, but the oxidative stability of stearins was greater than that of oleins. An increase in the percent enthalpy of crystallization and melting at lower temperatures was observed in oleins, with a consequent decrease in solid fat content, firmness and oxidative stability (compared with stearins) without a relevant change in the fatty acid profile, suggesting that triacylglycerols with unsaturated fatty acids were prevalent in positions sn1 and sn3 in oleins and in position sn2 in stearins. Thus, it was possible to obtain an olein with 26% less solid fat at 25 °C that was 22% less firm and that remained liquid until 3 °C below the oil, as well as a 23% firmer stearin.

Changes in quality and phytochemical contents of avocado oil under different temperatures.

Avocado oil, which has a high content of monounsaturated fatty acid and health-beneficial phytochemicals, is consumed in salads and also can be used for cooking. Therefore, is essential to study its oxidative and photochemical stability under different temperatures. So this work aimed to evaluate the oil oxidation and the phytochemical degradation of avocado oil under three different temperatures: room, 100 °C and 180 °C. The oil oxidation was evaluated by peroxide value and specific extinction in ultraviolet. The phytochemical degradation was evaluated for phytosterol, chlorophylls, and carotenoids contents. The temperature was found to significantly influence the oil oxidation and phytochemical stability, with the oxidation/degradation rate constants increasing with temperature. At room temperature, all oxidative parameters increased linearly with time, indicating a zero-order kinetic. At 100 and 180 °C, peroxide value, K232 and K270 increased linearly at a higher rate, becoming constant or decreasing after a short reaction time. The activation energy from specific extinction at 270 nm curves was 17.74 kcal mol-1 for oil degradation. For phytochemical compounds, the mechanism of reactions depended on the temperature, in which the reaction orders increased with heating. The activation energies for carotenoids, chlorophylls and sterols degradations at high temperatures were 5.00, 6.93, and 4.48 kcal mol-1, respectively. In this way, we found that avocado oil has its stability and quality affected by temperature, and, therefore, is not indicated for use in long and/or successive heating processes.

Multiple-sip temporal dominance of sensations associated with acceptance test: a study on special beers.

In this study, we proposed the use of a multiple-sip temporal dominance of sensations (TDS) test alongside with an acceptance test over repeated consumption for the analysis of special beers, with the aim of contributing to a deeper understanding of consumer behavior regarding temporal descriptions and sensory acceptance. Consumers of special beers sequentially evaluated six sips of a particular type of beer by TDS analysis and an acceptance test was performed for each sip. Four different kinds of specialty beers were evaluated [Bohemian Pilsner (BP), Witbier (WB), Belgian Strong Ale Dubbel (BD), and Russian Imperial Stout (RS)]. In general, the descriptive profile of beers varied temporally, i.e., there was an increased dominance of bitterness and a decreased dominance of fruity, floral, toffee, and coffee attributes. Concurrently, a reduction in sensory acceptance with an increased number of sips, especially the last sip, was observed in two kinds of beers that possessed a strong flavor, BD and RS. BP and WB presented smooth attributes and low notable characteristics, which could have contributed to the maintenance of the acceptance grades as the number of sips increased. The combination of TDS and acceptance over repeated sips can be useful for obtaining detailed descriptions of products that are closer to real time consumption by consumers, and thus aids in ensuring good product performance once released. The information obtained can also help product development scientists to fine-tune product formulations and ensure acceptability.

Temporal dominance of sensations and preferences of Brazilians and Slovakians: A cross-cultural study of cachaças stored with woods from the Amazon rainforest.

BACKGROUND: Brazilians and Slovakians evaluated the temporal profile and the acceptability of cachaça stored with different woods (Cumarurana (CM), Jatobá (JT) and, Louro-vermelho (LV), which are found in the Amazon rainforest, and also oak), with the aim of performing a cross-cultural comparison of the dynamic profile of the attributes perceived in the cachaças and the sensorial acceptance of the samples. RESULTS: Important differences were observed between the temporal sensorial profiles generated by the two groups and their preferences. Brazilians preferred cachaças stored with the traditional wood, oak, followed by those stored with JT and CM. In contrast, Slovakians preferred cachaças stored with JT, followed by those stored with LV and oak. For both countries, the dominance of wood flavor and vanilla attributes at the end of the analysis time was positively associated with acceptance, while the dominance of off-flavors and the wood flavor attribute at the beginning of the analysis time was negatively associated with acceptance for Brazilians and Slovakians, respectively. CONCLUSION: Brazilians preferred cachaça stored with oak wood, and Slovakians preferred cachaça stored with JT wood, with acceptability being strongly associated with the dominance of wood flavor and vanilla attributes at the end of the evaluation time. © 2018 Society of Chemical Industry.

Optimization of Low Sodium Salts Mix for Shoestring Potatoes.

Several studies have shown the close relationship between the sodium consumption and health problems such as hypertension and cardiovascular disease. Thus, the demand for products with reduced sodium content, but with sensory quality, is increasing every day. In this context, this study aimed to optimize a low sodium salts mix using sodium chloride, potassium chloride, and monosodium glutamate to the development of shoestring potatoes with low sodium content and high sensory quality, through mixture design and response surface methodology. The salts mix that promotes the same salting power and similar sensory acceptability that the shoestring potatoes with 1.6% sodium chloride (ideal concentration) and at the same time promotes the greatest possible reduction of sodium, about 65%, should provide the composition as follows: 0.48% of sodium chloride, 0.92% of potassium chloride, and 0.43% of monosodium glutamate.

Relationship between the chemical components of taro rhizome mucilage and its emulsifying property.

The objective of this study was to determine the chemical composition of taro mucilage (TM) and explain its emulsification properties using different commercial emulsifiers and gums as benchmarks. The following analyses were performed: moisture, ether extract, protein, fiber, ash, sugar fraction, starch content, infrared spectroscopy and determination of monosaccharides and amino acids using HPLC. The analyses showed that TM has a high carbohydrate content and small protein fraction, similar to commercial gums. Commercial emulsifiers have a high content of lipids compared to TM. Therefore, it can be concluded that the emulsifying power of the studied mucilage is primarily caused by the protein content along with weakly polar amino acids, which occur in gums. The methyl group (CH3), which was observed in the infrared spectrum, and the lipid content may also contribute to the emulsifying activity by providing a hydrophobic moiety.

The use of statistical software in food science and technology: Advantages, limitations and misuses.

Strict requirements of scientific journals allied to the need to prove the experimental data are (in)significant from the statistical standpoint have led to a steep increase in the use and development of statistical software. In this aspect, it is observed that the increasing number of software tools and packages and their wide usage has created a generation of 'click and go' users, who are eagerly destined to obtain the p-values and multivariate graphs (projection of samples and variables on the factor plane), but have no idea on how the statistical parameters are calculated and the theoretical and practical reasons he/she performed such tests. However, in this paper, some published examples are listed and discussed in detail to provide a holistic insight (positive points and limitations) about the uses and misuses of some statistical methods using different available statistical software. Additionally, a brief description of several commercial and free statistical software is made highlighting their advantages and limitations.

Rapid extraction of melamine in powdered milk for direct electrospray ionization tandem mass spectrometry analysis.

A combination of a simple pretreatment for melamine extraction and direct analysis in electrospray ionization tandem mass spectrometry (ESI-MS/MS) is proposed. Three pretreatments were evaluated. The first was based on suppressing interference using acetonitrile. The second used sulphuric acid and trichloroacetic acid to suppress interference and for melamine extraction, respectively. The third used sulphuric acid to suppress milk interference, trichloroacetic acid for melamine precipitation, and ethyl acetate for melamine extraction. However, only the last pretreatment suppressed milk interference in melamine detection and a good linearity (R(2)=0.99) was obtained. The presence of MS/MS 85 on melamine fragmentation spectrum showed the selectivity of this method. The limit of detection and limit of quantification were 0.269 µg L(-1) and 0.897 µg L(-1), respectively. The recoveries and relative standard deviation (RDS) of method were lower than 114% and 7.86%, respectively. Further, the research was extended to elucidate the nature of the melamine in the extract through infrared spectroscopy and microscopy analyses. The precipitate was characterized as melaminium bis(trichloroacetate) dihydrate, which is generated through hydrogen bound formation in an interaction between melamine and trichloroacetic acid. Therefore, a simple, fast, and easy method for melamine extraction and direct ESI-MS/MS analysis was developed.

Fish filleting residues for enrichment of wheat bread: chemical and sensory characteristics.

The fish processing industry generates a large amount of materials discarded as residue. It is known that fish and its residue are a source of essential nutrients. Conversely, bread is a food accessible to different social classes but is deficient in protein, minerals, and fatty acids. Thus, this study aimed to develop bread products based on the addition of flour from Red-tailed Brycon (Brycon cephalus) processing residue and then evaluate the chemical and sensory qualities of the products. In relation to a standard bread formulation without fish flour, the addition of fish flour to bread formulations resulted in products with not only higher contents of protein, essential fatty acids, and minerals, especially calcium and phosphorus, but also lower contents of carbohydrates. The breads with fish flour received sensory acceptance better than or as good as that of a bread formulation without fish flour. Hence, the addition of fish processing residue to breads is a way to provide essential nutrients to the population through a well-accepted, accessible, and low-cost product.

Evaluation of the jelly processing potential of raspberries adapted in Brazil.

UNLABELLED: Generally raspberry products as jams, jellies, and preserves are made with red raspberry, however, yellow raspberry and especially black raspberry are also fruits adapted in Brazil, presenting even better productivity and quality. Thus, the aim of this study was to evaluate the processing potential of other varieties of raspberry, but the red, in the preparation of jellies through mixture design and response surface methodology (RSM). These techniques were used to optimize the following 3 variables: yellow (Golden Bliss cultivar, Rubus idaeus), black (Rubus niveus), and red raspberries (Batum cultivar, Rubus idaeus) to formulate a mixed raspberry fruit jelly through sensory evaluations. It was found that jelly formulated with a mix of colored raspberries grown in subtropical regions is a viable and alternative way to use yellow and black raspberries. The mixed raspberry jelly must have 0% to 30% yellow raspberries, 25% to 50% black raspberries, and 30% to 75% red raspberries. Within this region, the optimum formulation has ideal characteristics that are often not observed in formulations with 100% black or yellow raspberries. PRACTICAL APPLICATION: The black and yellow raspberries are little explored in fresh consumption and in the development of products such as jams and jellies. From these work, using mixture design and response surface methodology, has been verified that the production of a mixed raspberry jelly seems feasible and is an interesting alternative to use the yellow and black raspberries. The results serve as a guide to the production of jams and jellies from these types of raspberries.

Fourier transform infrared spectroscopy and partial least square regression for the prediction of substrate maturity indexes.

Traditional methods to evaluate the stability and maturity of organic wastes and composting matrices are laborious, time-consuming and generate laboratory chemical wastes. This study focused on the development of partial least square (PLS) regression models for the prediction of the stability and maturity of compost-based substrates based on Fourier transform infrared (FTIR) spectroscopy. The following parameters, selected as conventional maturity indexes, were modeled and used as dataset: dissolved organic carbon (DOC), C/N and NH4(+)/NO3(-) ratios, cation exchange capacity (CEC), degree of polymerization (DP), percentage of humic acid (PHA), humification index (HI) and humification ratio (HR). Models were obtained by using data from a wide range of compost based growing media of diverse origin and composition, including 4 commercially available substrates and 11 substrates prepared in our facilities with varying proportions of different organic wastes. The PLS models presented correlation coefficient of calibration (R(2)cal) close to 0.90 and correlation coefficient (R(2)) of cross validation (R(2)cv) presented acceptable values (>0.6), ranging from 0.67 (HR) to 0.92 (C/N). The good performance of the method was also confirmed by the low correlation obtained from the Y-randomization test. R(2) for test samples (R(2)pred) ranged from 0.66 (C/N) to 0.97 (HI) confirming the good correlation between measured and PLS predicted maturity indexes. FTIR spectroscopy combined with PLS regression represents, after modeling process, a fast and alternative method to assess substrate maturity and stability with reduction of time, lower generation of laboratory chemical wastes residues and lower cost per sample than conventional chemical methods. All models adjusted for maturity indexes are predictive, robust and did not present chance correlation.

Use of allyl isothiocyanate and carbon nanotubes in an antimicrobial film to package shredded, cooked chicken meat.

We developed antimicrobial packaging incorporated with allyl isothiocyanate (AIT) and carbon nanotube (CNT), and this packaging was used for shredded cooked chicken meat inoculated with Salmonella Choleraesuis. The following parameters were analysed during the 40 days of storage: microbial counts, colour characteristics and changes in the oxidation of the meat as well as changes in the mechanical properties of the film, the structure of the antimicrobial film and the diffusion of the antimicrobial agent into the food. The incorporation of AIT into the films increased the elongation at the break (E) value of the films and decreased the tensile strength (TS) value of the films. The CNT was important to retain the AIT which is a volatile substance in the film. The diffusion of the AIT from the film into the chicken reduced the microbial contamination, controlled oxidation and reduced the colour changes. Thus, these packages were effective for the 40 days of storage.

Salt equivalence and temporal dominance of sensations of different sodium chloride substitutes in butter.

Studies indicate a positive association between dietary salt intake and some diseases, which has promoted the tendency to reduce the sodium in foods. The objective of this study was to determine the equivalent amount of different sodium chloride replacements required to promote the same degree of ideal saltiness in butter and to study the sensory profile of sodium chloride and the substitutes using the analysis of Temporal Dominance of Sensations (TDS). Using the magnitude estimation method, it was determined that the potencies of potassium chloride, monosodium glutamate and potassium phosphate relative to the 1% sodium chloride in butter are 83·33, 31·59 and 33·32, respectively. Regarding the sensory profile of the tested salt substitutes, a bitter taste was perceived in the butter with potassium chloride, a sour taste was perceived in the butter with potassium phosphate and sweet and umami tastes were dominant in the butter with monosodium glutamate. Of all the salt substitutes tested calcium lactate, potassium lactate, calcium chloride and magnesium chloride were impractical to use in butter.

Chemical, physical-chemical, and sensory characteristics of lychee (Litchi chinensis Sonn) wines.

UNLABELLED: Four lychee (Litchi chinensis Sonn) wines (prepared with 3 yeast strains [UFLA CA11, UFLA CA1183, and UFLA CA1174]) and a spontaneous fermentation (SPON) were done in order to add value to the fruit while preventing waste arising from the short shelf life of lychee. The fermentation was monitored daily by analyzing the soluble solids, pH, acidity, ethanol, and sugar. At the end of fermentation, the wines were subjected to chemical, physical-chemical, and sensory analysis. The wines prepared showed greater variations in the qualitative than in the quantitative analysis of their constituents. The sensory analysis indicated that the wines fermented by yeast UFLA CA1183 and UFLA CA11 had rates of acceptance above 75%. The principal components analysis separated the wines into 2 groups according to the analyzed compounds. Based on these analyses, the wine produced by inoculation with UFLA CA1183 proved to be the most suitable for the production of lychee wines. PRACTICAL APPLICATION: Development of new products and adding value to fruits. Importance of selection of specific yeasts for production of fruit wine.