Total Titratable Acidity Values Research Articles

Rock Powder Enhances Soil Nutrition and Coffee Quality in Agroforestry Systems

The use of rock powders is an agricultural practice that facilitates the agroecological transition and autonomy of many farmers. These inputs should be used in conjunction with management systems that enhance the weathering of the minerals contained in the rocks. This study aimed to assess the impact of incorporating gneiss powder on soil quality and coffee cultivation within agroecological and organic frameworks, encompassing agroforestry systems (AFSs) as well as areas fully exposed to sunlight (FS). Comprehensive analyses, including chemical, microbiological, and physical assessments, were carried out on the soil. The study involved evaluating various parameters such as electrical conductivity, grain density, total titratable acidity, and pH of the exudates to gauge the coffee quality. Following a 24-month application of rock powder, noteworthy observations included increased soil moisture in agroforestry systems (AFSs), presumably attributable to enhanced nutrient availability (potassium, calcium, magnesium, copper, and zinc) derived from the gneiss powder. In addition, a higher level of CO2 was derived from microbial respiration than from soil production. Similarly, coffee beans presented lower electrical conductivity, higher density, and fewer defects in AFSs than fully exposed sun systems (FS). The total titratable acidity values remain consistent with the limits indicated in the literature for quality coffees; the pH values, however, were lower. The results suggest that the use of gneiss powder enhances soil microorganism activity and accelerates the biological weathering of minerals for coffee plantations in AFSs.

Nutritional and Sensory Evaluation of Yoghurt Incorporated with Unripe False Horn Plantain (Musa paradisiaca var. "apentu").

Unripe plantain (Musa paradisiaca L.) is rich in nutrients including minerals, vitamin C, and carbohydrates particularly resistant starches with prebiotic properties. However, the fruit is challenged with limited utilisation, and this contributes to its high postharvest losses along the production and supply chain. Information is lacking on incorporating plantain (UPF) in functional dairy food product development. In a completely randomized design, the study evaluated the effect of unripe false horn plantain (var. "apentu") flour (UPF) incorporation (w/v), at 0% (control), 2%, 4%, and 6%, on the composition and sensory quality of yoghurt. The results showed that higher UPF percent incorporation resulted in yoghurts having lower moisture and higher total solid values as well as enhanced nutritional values, in terms of protein, zinc, potassium, calcium, and vitamin C (P < 0.05). Mean pH and total titratable acidity values of the yoghurt products were in the ranges of 3.40-3.65 and 1.00-130%, respectively. Conversely, an increase in UPF incorporation generally reduced consumer likeness scores for yoghurt sensory characteristics including appearance, texture, flavour, taste, aftertaste, and overall acceptability. The control AZ product received the highest ratings in all sensory attributes evaluated. Compared with the control AZ, the BX (2% w/w UPF) yoghurt showed better nutritional quality as well as had comparable ratings for the sensory attributes, particularly in terms of appearance, texture, and flavour. Thus, the formulation containing 2% UPF has the best potential for the production of value-added functional yoghurt, which will be acceptable. However, for high acceptability, further research is needed to improve the impact of UPF incorporation on the overall sensory quality of yoghurt. The study suggests that UPF can serve as a potential supplement for improving the value of yoghurt, and this also contributes to reducing postharvest losses of plantain as a key food security resource. Also, the study findings contribute baseline information to guide future research on functional dairy product development with unripe plantain.

The Application of Various Fermented Malang Apple Water As A Source of Natural Yeast for Sourdough Bread Processing

The sourdough fermentation method is identified as a complex microbial ecosystem stimulant by the spontaneous natural water starters process. At the fermentation time, lactic acid bacteria and yeast confer the resulting characteristic bread features such as staling of bread, and palatability. With the scope of highlighting fermentation, the investigation of starter culture is relevant in order to determine starch fractions of flour. The present article employed water from apple local varieties of Malang as a mixture of natural yeast. The research was conducted in two stages. The first stage was to get the best apple variety to produce the optimum quality of sourdough starter. The second was applying the best sourdough starter at various concentrations in bread formulation. Parameters observed included yeast, and lactic acid bacteria counts, pH, Total Titratable Acidity (TTA), lactic acid content, hardness, loaf volume, specific volume, and sensory properties of sourdough bread. There was an influence on the treatment of making a sourdough starter with different types of apple fruit and showed the best treatment if sourdough starter of fermented manalagi apple water with a pH value of 4.5, TTA value of 2.71 mL, the number of lactic acid bacteria of 5.6 × 1010 CFU/mL, and the number of yeast of 2.62 × 1011 CFU/mL.

The Optimisation of Bitter Gourd-Grape Beverage Fermentation Using a Consolidated Response Surface Methodology (RSM) and Artificial Neural Network (ANN) Approach.

The present study adopted a response surface methodology (RSM) approach validated by artificial neural network (ANN) models to optimise the production of a bitter gourd-grape beverage. Aset of statistically pre-designed experiments were conducted, and the RSM optimisation model fitted to the obtained data, yielding adequately fit models for the monitored control variables R2 values for alcohol (0.79), pH (0.89), and total soluble solids (TSS) (0.89). Further validation of the RSM model fit using ANN showed relatively high accuracies of 0.98, 0.88, and 0.82 for alcohol, pH, and TSS, respectively, suggesting satisfactory predictability and adequacy of the models. A clear effect of the optimised conditions, namely fermentation time at (72 h), fermentation temperature (32.50 and 45.11 °C), and starter culture concentration (3.00 v/v) on the total titratable acidity (TTA), was observed with an R2 value of (0.40) and RSM model fit using ANN overall accuracy of (0.56). However, higher TTA values were observed for samples fermented for 72 h at starter culture concentrations above 3 mL. The level of 35% bitter gourd juice was optimised in this study and was considered desirable because the goal was to make a low-alcohol beverage.

Biotechnological Features of a Functional Non-Dairy Mixed Juice Fermented with Lacticaseibacillus paracasei SP5

In the present study, a wild-type Lacticaseibacillus paracasei SP5 (L. paracasei SP5) potential probiotic strain (previously isolated from kefir grains) was applied for the 1-day fermentation of an apple–orange–carrot mixed juice. After the fermentation, the mixed juice was refrigerated in cold storage at 4 °C, and the microbiological stability, characterization of volatiles, physicochemical properties (pH, total titratable acidity (TTA), residual sugar content and organic acids content), the sensorial validation (aroma, taste and overall acceptability) of the juice, and the viability of the potential probiotic strain were analyzed. The stored juice exhibited zero colonies of yeasts/fungi and simultaneously the viability of L. paracasei SP5 was retained to 8.28 Log CFU/mL, even after the 4th week of cold storage. The pH values ranged from 3.80 to 3.35 and the TTA values ranged from 0.1344% to 0.1844% lactic acid for the unfermented juice up until the 4th week of cold storage. Furthermore, the organic acids content consisted mostly of lactic acid (4.6 to 9.1 g/L), while malic acid (3.7 to 1.5 g/L), acetic acid (0.6 g/L) and propionic acid (0.3 g/L) were detected only after the 4th week of cold storage. Residual sugar content ranged from the initial value of 122.2 g/L and 106.6 g/L at the end of cold storage. As far as the volatiles’ characterization is concerned: 9 esters, 2 organic acids, 12 alcohols, 3 aldehydes, 1 ketone, 6 terpenes and 4 sesquiterpenes (37 in total) were detected in the unfermented mixed juice and 33 compounds in the fermented juice after 4 weeks of cold storage. The sensorial properties (aroma, taste and overall acceptability) of the fermented mixed juice samples were positively influenced. Consequently, L. paracasei SP5 potential probiotic strain may be applied for the production of probiotic mixed juices, with satisfying viability, volatile profile and organoleptic results.

Effect of apple peel extracts on storage quality of quince juice

Enzymatic browning is one of the reactions influencing the quality of some fruit juices such as quince juice. Nowadays, there is an increased demand for application of antibrowning agents. This research was aimed at the effects of using each ethanolic and aqueous apple peel extracts (EAPE, AAPE) in two concentrations (0.3 and 3%) as inhibitor agents for polyphenol oxidase activity (PPO) of quince juice and their effects on the browning index (BI), total soluble solids (TSS), pH, total titratable acidity (TA), and total phenolic content (TPC) during storage at 4°C for 15 d. The effectiveness of 3% (w/v) alcoholic apple peel extract efficiently inactivated the activities of PPO compared with another three extracts during whole refrigerated storage time. The lowest inhibition percentage value of BI was found in 0.3% AAPE supplemented quince juices. EAPE and AAPE with concentrations of 3% had significantly larger pH values than that of EAPE and AAPE with concentration 0.3% and untreated quince juices at a final day of cold storage. TA values of juice samples untreated and treated with apple extracts did not show significant changes that ranged between 74-75 mg/100 ml at the beginning of storage and decreased with increased storage time, ranging between 0.68-0.72 mg/100 ml at the end of storage. The addition of apple peel extracts during the storage of quince juice had a positive effect on TSS values of the samples. Significantly larger TPC values (P&lt;0.05) were obtained with 3% EAPE incorporated juice samples in comparison with other treatments.

Physicochemical and microbiological properties of Arabic flatbread produced from wild natural sour starters

Background and objectivesExtensive research studies worldwide have discussed and analyzed the sourdough nutritional, chemical, and biotechnological aspects of western types of bread. However, the literature on sourdough usage in Arabic bread processing is very limited. The present study aimed to come up with a new fermentation technique at the bakery level. The new technique is hoped to reveal the traditional nostalgic characteristic flavor of Arabic bread produced using natural sourdough instead of the traditional yeasted dough and study its effect on the resulting bread. Three types of flour (straight grade, whole wheat, and rye) that are ordinarily used in Jordan were used to prepare three natural sour starters using the backslopping technique. FindingsDominant yeast species isolated from the traditional sour starter of the local Jordanian whole wheat were Saccharomyces cerevisiae, Candida glabrata, and Zygosaccharomyces spp., while rye and straight-grade starters showed different domination patterns. The dominant species of lactic acid bacteria (LAB) isolated from the traditional sour starter of the local Jordanian whole wheat (Horani cultivar) were Lactiplantibacillus plantarum2, Lactobacillus delbrueckii ssp bulgaricus, and the Lacticaseibacillus paracasei ssp paracasei3, while mixed strains of LAB isolates were obtained for the rye and straight-grade flour starters on day 7 of preparation.The pH results showed no significant differences (P > 0.05) between the three types of sour starters, while the total titratable acidity (TTA) results showed a significant increase (P ≤ 0.05) in whole wheat sour starters with a TTA value of 11.17 ± 0.11 ml 0.1 N NaOH/10g dough. The 20% and 30% straight-grade sour bread samples and the control exhibited the highest scores in terms of acceptability and total quality scores. ConclusionsThe incorporation of sourdough in Arabic flatbread processing showed remarkable results in extending the shelf life by using natural ingredients, improving the quality, and providing tastier and more convenient bread.

Root morphology, yield and must composition of grapevine subjected to application of urea methods and rates

Nitrogen (N) is often applied to soil surface during the grapevine cycle, increases N losses. One way to reduce N losses lies on its application method, however how N dose and application mode impact on grapevines remain poorly investigated. The aim of this study is to evaluate the root growth, as well as grape must yield and composition, in a sandy soil and subjected to different N application doses and modes under subtropical climate conditions. Grapevines were implanted in 2011 and, since 2014, they were subjected to surface (N-Surf), and fertigation (N-Fert) N application, at rates of 0, 40 and 100 kg N ha−1 year−1. Leaf N concentration, yield, must quality parameters and root system morphology were evaluated in the 2016/2017 and 2017/2018 seasons. The application of N in both rates (40 and 100 kg N ha−1 year−1), in the N-Surf and N-Fert methods, increased the surface area of root, number of living roots and root production. The application of N rates, in both N application modes, provided adequate N supply to the soil and increased root system development, which contributed to the increase of soil N uptake by plants, higher N concentration in leaves and greater grape yield. However, N supply decreased the quality of the must, as observed in decreased TSS and total anthocyanins values and in increased total titratable acidity values, which are not desirable for red wine making processes.

Maturity indices of specific mango varieties produced at medium altitude agro-ecological zone in Kenya

The high postharvest losses (40 – 50%) reported in the mango value chain are partly attributed to lack of reliable maturity indices. Harvest maturity is dictated by the intended use and the target market for the fruits. The aim of this study was to establish maturity indices of three commercial mango varieties namely ‘Van dyke,’ ‘Kent’ and ‘Tommy Atkins’ in Embu County of Kenya. At least eighteen mango trees (six per variety) were randomly tagged at 50% flowering in each of the three selected small-scale farms in Embu County. Number of days from flowering to different maturity stages were recorded (computational method). For each variety and maturity stage, five fruits were randomly sampled from the pool and analysed for physical (size, density, firmness, colour), physiological (ethylene evolution and respiration rate) and biochemical (obrix/Total Soluble Solids (TSS), total titratable acidity (TTA) and their ratio) indices of maturity. The results showed that although size increased as the fruits developed, it was not a reliable index of maturity since some small-sized fruits attained advanced maturity earlier than others that were large-sized. The weight of the fruits fluctuated as the fruits developed and similar trend was observed on the specific gravity. Flesh firmness decreased gradually with maturity from a mean firmness of 40.54 N to 6.84 N. Tommy Atkins exhibited the lowest firmness levels at stage 4. Kent variety had the lowest ethylene at all stages while Tommy Atkins variety had the highest respiration rate of 21.40 ml/kg/hr at stage 1, which increased gradually to 32.10 ml/kg/hr at stage 4. The highest TSS: TTA values were reported in Kent variety. The results revealed significant differences in maturity indices of the three mango varieties despite similar physical indices. This study confirms the unreliability of physical maturity indices such as size and shape in establishing the right harvest stage of mango fruits. Computational, physiological and biochemical maturity indices should be incorporated in determination of accurate harvest maturity for mango. Key words: Ethylene, Harvest maturity, ‘Kent’, Maturity indices, Respiration, ‘Tommy Atkins’, ‘Van dyke’

Liquid sourdough from stone-ground soft wheat (Triticum aestivum) flour: Development and exploitation in the breadmaking process

The aim of the study was to set up a liquid sourdough obtained using stone-ground soft wheat (Triticum aestivum) flour to be exploited in breadmaking. Therefore, a Type II sourdough (dough yield = 350) was developed from a stable stone-ground wheat Type I sourdough (dough yield = 156) used as inoculum. Both sourdoughs were analyzed for lactic acid bacteria (LAB) viable counts, pH and total titratable acidity (TTA), LAB biodiversity by a combined culture-dependent and -independent approach (PCR-DGGE) and they were tested for their breadmaking ability. In addition, the chemical and rheological features and volatile organic compounds of the stone-ground soft wheat flour used in the experiment were investigated.The flour had a high protein content, good bakery properties and it also presented a rich aroma pattern characterized not only by the prevalence of green grass, flowery, and sweet aromas but also nutty, roasted and popcorn aromas.The sourdoughs I and II used in the trial were characterized by viable LAB counts, pH and TTA values typical of mature sourdoughs, i.e., approximately 9 log cfu gr-1 and mL, pH 3.9 and 10 mL 0.1 N NaOH. In addition, Levilactobacillus brevis and Companilactobacillus paralimentarius species represented the LAB stable microbiota of both sourdoughs.Both sourdoughs efficiently produce acceptable experimental breads characterized by different volatile profiles thus indicating that the type of sourdough fermentation significantly influenced the features of the final products. Overall, for the first time in the present study stone-ground wheat flour and bread have been characterized for their volatile aroma profile and sensory properties.

Development of antioxidative red dragon fruit bar by using response surface methodology for formulation optimization

Optimization of ingredient levels in red dragon fruit bar was conducted using response surface methodology (RSM). The central composite design (CCD) was used to establish the formula based on two independent variables, including levels of passion fruit and pectin. Total titratable acidity (TTA), ascorbic acid (AA), betacyanin (BA), total phenolic content (TPC), flavonoid content (FC), antioxidant activity (DPPH radical scavenging activity), color (L*-, a*-, and b*- values), and sensory evaluation (overall likeness score) were monitored. It was found that second-order regression models fitted for all responses where the optimum levels of passion fruit and pectin for mixed red dragon-passion fruit bar with desirable characteristics were 29.63% and 1.35%, respectively, based on desirable characteristics. The corresponding optimum values of TTA, AA, BA, TPC, FC, and DPPH radical scavenging activity were 2.30%, 0.0189%, 49.34 mg/100 g, 0.33 mg GAE/g, 75.29 mg QE/g, 11.46%, respectively. L*-, a*-, and b*- values were 13.10, 21.39, and 13.83, respectively. An overall likeness score of the fruit bar with high acceptability was 7.67. The experimental values were highly fitted with the predicted values.

Avaliação físico-química e microbiológica de águas de coco produzidas na cidade de Juazeiro do Norte, Ceará

Objetivo: O objetivo deste estudo foi realizar uma investigação da qualidade de águas de coco produzidas na cidade de Juazeiro do Norte, Ceará, a nível físico-químico e microbiológico, e verificar se estão de acordo com a legislação vigente (Nº 27, de 22 de julho de 2009). Métodos: Três marcas diferentes foram utilizadas neste estudo, onde foram denominadas de A, B e C, do tipo envasadas e resfriadas. Foram analisados acidez total titulável, pH, sólidos solúveis totais, açúcares redutores e presença de alguns microrganismos (Salmonella sp., Escherichia coli, Bolores e leveduras). Resultados: As análises físico-químicas demostraram que o pH de todas as amostras estão acima do limite permitido, já os sólidos solúveis totais se enquadraram na normatização, os valores de acidez total titulável e de açúcares redutores encontram-se abaixo dos valores mencionados na literatura. Os resultados das análises microbiológicas qualitativas mostram que há presença de todos os microrganismos antes citados em todas as amostras. Conclusão: Por fim conclui-se que todas as amostras se encontram insatisfatórias, por não estarem seguindo as boas práticas de fabricação, assim necessitando-se de um controle mais rígido.

Potential Natural Dyes Food from the Powder of Prickly Pear Fruit Peels (Opuntia spp.) Growing in the Mediterranean Basin under Climate Stress.

Background Barbary fig (Opuntia spp), called prickly pear, is a cultivated species belonging to family Cactaceae. It produces fruits one time per year during a short season. It is largely spreading in the Mediterranean countries. The aim of the study was to investigate the physicochemical and biochemical analysis of powder of prickly pear fruit peels of three Moroccan varieties (Aakria, Derbana, and Mles). Material and Methods. Both physicochemical analysis (humidity, water activity, Brix, ash content, pH, and total titratable acidity) and biochemical analysis (total carotenoid content, betalain content, total polyphenolic content, and ascorbic acid content) were effectuated according to protocols reported within the present research work. Results Regarding the physiochemical analysis, the humidity of powder of prickly pear fruit peels ranged from 10.173 ± 0.002 to 15.27 ± 0.02%. The water activity (aw) ranged from 0.17 ± 0.002 to 0.336 ± 0.002. The values of Brix ranged from 68.67 ± 0.33 to 74.22 ± 0.51° Bx. pH values ranged from 5.41 ± 0.01 to 5.62 ± 0.01. The total titratable acidity values ranged from 0.644 ± 0.014 to 0.76 ± 0.007 g citric acid/100 g DM (dry matter). The ash content ranged from 1.02 ± 0.02 to 11.41 ± 0.03 g/100 g DM. Regarding the biochemical analysis, the total carotenoid content ranged from 5.14 ± 0.10 to 9.79 ± 0.06 mg/g of FM (Fresh matter). The total betalain content ranged from 2 ± 0.69 to 37.66 ± 2.65 mg/100 g of DM. The total polyphenolic content ranged from 1739.92 ± 13.69 to 2409.66 ± 43.65 mg gallic acid equivalent (GAE)/100 g of DM. The ascorbic content values ranged from 186.78 ± 13.23 to 294.04 ± 5.81 mg/100 g of DM. Conclusion The results showed an interesting richness of the investigated powder in pigments (betacyanins, indicaxanthins, and carotenoids) and nutritional compounds including sugar, proteins, and vitamins that make this powder interesting for being used as a dye in food.

Promising Physical, Physicochemical, and Biochemical Background Contained in Peels of Prickly Pear Fruit Growing under Hard Ecological Conditions in the Mediterranean Countries.

Background Prickly pear (Opuntia spp.), called Barbary fig, is a cultivated species springing from family Cactaceae. It is native to Mexico and has been naturalized in other continents, especially the Mediterranean countries (North Africa). The aim of the study was to investigate the physical, physicochemical, and biochemical criteria of peels of three Moroccan prickly pear varieties (Aakria, Derbana, and Mles) growing in the Rhamna regions (dry area). Material and Methods Both physicochemical characteristics (humidity, water activity, Brix, ash content, pH, and total titratable acidity) and biochemical characteristics (total carotenoid content, betalain content, total polyphenolic content, and ascorbic acid content) were were studied according to previously reported methods. Results Regarding the physiochemical criteria, the moisture of the fresh peels of studied varieties ranged from 81.59 ± 0.02 to 83.47 ± 0.02%. The water activity (aw) ranged from 0.862 ± 0.001 to 0.872 ± 0.001. The values of Brix varied from 14.69 ± 0.05° Bx to 15.80 ± 0.03° Bx. pH values varied from 5.13 ± 0.01 to 5.32. The total titratable acidity values ranged from 0.130 ± 0.008 to 0.196 ± 0.014 g of citric acid/100 g of FM (fresh matter). The ash content values ranged from 8.92 ± 0.10 to 11.04 ± 0.06 g/100 g of FM. Regarding the biochemical criteria, the total carotenoid content ranged from 2.29 ± 0.01 to 2.87 ± 0.01 μg/g of FM. The total betalain content ranged from 6213.46 ± 58.86 to 8487.19 ± 51.71 μg/100 g of FM. The total polyphenolic content varied from 160 ± 3.55 to 243.79 ± 5.55 mg GA E/100 g of FM. The ascorbic content ranged from 58.21 ± 0.24 to 74.72 ± 0.17 mg/100 g of FM. Conclusion The findings of physicochemical and biochemical criteria of the investigated varieties growing in Moroccan drylands showed promising results in terms of studied parameters.

Physicochemical quality, antioxidant capacity and nutritional value of edible flowers of some wild dahlia species

Abstract Mexico is the centre of origin and domestication of the dahlia, which has the widest distribution worldwide as an ornamental plant; however, due to changes in eating habits in some sectors of the population (vegetarians and vegans), it has also been incorporated as an ingredient in the gastronomic field. The aim of this research was to determine the attributes of physicochemical quality, antioxidant capacity and nutritional value of ligulate flowers of some wild dahlia species. A completely randomized experimental design with five repetitions was used. Fresh weight, total titratable acidity (TTA), total soluble solids (TSS), ascorbic acid (AA), colour, total phenols (TP), total flavonoids (TFl), total anthocyanins (TAn), antioxidant capacity (AC) and proximate composition were evaluated. The highest fresh weight was observed in D. × hortorum, with similar values among its different flower colours. Likewise, D. merckii and D. coccinea stood out for their high TTA value; however, D. coccinea also had the highest AA content (0.77-0.9 mg g−1 FW), TP (12.87-19.92 mg GAE g−1 FW), TFl (6.78-11.32 mg QE g−1 DW) and AC (47.28-60.43 mg AAEVC g−1 FW). On the other hand, D. campanulata was notable for its high levels of moisture, fat and raw fibre; similarly, D. coccinea stood out for its high amounts of dry matter and total carbohydrates. The ligulate flowers of wild dahlias have a high concentration of bioactive compounds and a nutritional composition with beneficial contributions to health care, so they could be used for consumption as fresh products.

Effect of sorghum sourdough and nabag (zizyphus spina-christi) pulp powder on dough fermentation and quality characteristics of bread

Sorghum sourdough made with lactic acid bacteria (LAB) and fruit products are of interest in the preparation of a variety of fermented baked products. In this study, different levels (10, 20, and 30%) of sorghum sourdough were fermented by a blend of L. plantarum and L. brevis and various levels of dry nabag pulp powder (1, 3, 5, and 7%). Physicochemical properties of dough and bread as well as the sensory evaluation were determined. Sorghum sourdough' pH decreased from 6.30 to 3.54, total titratable acidity (TTA) increased from 2.8 to 15 mL and bacteria count increased from 6.00E + 08 to 1.14E + 09, CFU/mL after 24 h of fermentation. The addition of sorghum sourdough and nabag powder progressively decreased pH and increased TTA values of bread and dough compared to the controls. Nabag powder significantly (p < 0.05) increased maximum dough fermentation height (Hm), compared to the control, however the other samples were lower (p < 0.05). The maximum gas fermentation height (H’m) and gas properties increased (p < 0.05) for all samples with different addition levels. Crust and crumb color were not affected by sorghum sourdough and nabag pulp powder except for 30% sorghum sourdough and 7% nabag pulp powder. These results showed sorghum sourdough and nabag pulp powder can be used in the bread formulations.

Antagonistic lactic acid bacteria in association with Saccharomyces cerevisiae as starter cultures for standardization of sour cassava starch production

In order to improve cassava's palatability and reduce its toxicity, this root is fermented and applied in foods, such as sour cassava starch used to prepare cheese bread and biscuits. This fermentation occurs spontaneously with lactic acid bacteria (LAB) and yeasts. However, it remains an empirical process, with long duration and lack of product quality homogeneity. This work aims to use starter cultures in a pilot-scale fermentation process for the production of sour cassava starch. After differentiation of strains, Lactobacillus plantarum Lp3, which exhibited great total titratable acidity (TTA) (5.01 ± 0.05%) and antagonistic activity against Bacillus cereus, Escherichia coli and Salmonella Typhimurium, together with Lactobacillus brevis Lb9 (with lesser TTA values: 2.71 ± 0.10%, but amylolytic activity: 2.75 ± 0.61mm) were tested as single and co-cultures with Saccharomyces cerevisiae UFMG-A1007. LAB and yeasts were inoculated at counts of 8 and 7 log10 CFU/g, respectively, and they remained until the 28th day only in co-culture, highlighting the importance of the yeast for the LAB viability. Although single cultures lead to higher acidity during fermentation, the final product acidity obtained with single cultures did not differ from the acidity obtained with L. plantarum Lp3 in association with S. cerevisiae UFMG-A1007. Therefore, this co-culture exhibited higher potential to be tested as a starter culture in industrial-scale fermentation studies because both microorganisms were in high counts until the end of fermentation and contributed to a final product safe for human consumption, with satisfactory acidity, expansion capacity, and physicochemical properties.

‘Niágara Rosada’ and ‘Isabel’ grapes quality cultivated in different altitudes in the state of Espírito Santo, Brazil

Altitude and climate and its microclimatic characteristics influence the grapes and wines quality. The objective of this study was to evaluate ‘Niagara Rosada’ and ‘Isabel’ grapes quality at three different altitudes in the highlands of the state of Espírito Santo. The experiment was a randomized complete block design in subdivided plots (3x2). The plots were in different altitudes and, in the subplots, the two cultivars. Also, five replicates were done in each treatment. The grapes quality were evaluated in the laboratory from total soluble solids (TSS), total titratable acidity (TTA), pH and the relationship between TSS / TTA. The cultivar ‘Niágara Rosada’ showed higher values than the ‘Isabel’ cultivar in relation to the evaluated parameters. The altitude of 650 m favored to obtain higher values of total titratable acidity and lower values of pH. The excess of leaf nitrogen in environment 1 contributed to the higher values of TTA and lower pH for the cultivars ‘Niágara Rosada’ and ‘Isabel’. The quality of the ‘Niágara Rosada’ and ‘Isabel’ grapes produced in the state of Espírito Santo were influenced by altitude, and the altitude of 650 m favored to obtain higher values of total titratable acidity and lower values of pH.

Production and postharvest quality of yellow passion fruit cultivated with saline water and hydrogen peroxide

The present study aimed to evaluate the production and postharvest quality of yellow passion fruit, cultivated under different levels of irrigation water salinity and exogenous application of hydrogen peroxide. At low concentrations, hydrogen peroxide may favor plant acclimatization when subjected to saline stress conditions due to the activation of defense mechanisms. The experiment was conducted in greenhouse in the municipality of Campina Grande-PB, Brazil, using drainage lysimeters filled with sandy loam Entisol. The experimental design was randomized blocks, with 4×4 factorial arrangement with three replicates, consisting of four levels of irrigation water electrical conductivity—ECw (0.7, 1.4, 2.1 and 2.8 dS m-1) and four concentrations of hydrogen peroxide—H2O2 (0, 20, 40 and 60 μM). The different concentrations of H2O2 were applied by soaking the seeds for a 24-h period before sowing and spraying the leaves on the adaxial and abaxial sides. At the end of the cycle (205 days after transplanting-DAT), passion fruit production was evaluated by determining the number of fruits per plant, mean fruit weight and total fruit weight. Postharvest quality was determined by physical characterization of fruit (equatorial and polar diameters and rind and pulp thicknesses), hydrogen potential in the pulp, titratable acidity and ascorbic acid. Increasing levels of irrigation water salinity negatively affected the production and physical and chemical quality of passion fruits. Number and total weight of fruits per plant were the most compromised variables. There was significant interaction between irrigation water salinity levels and H2O2 concentrations on fruits’ polar diameter, at 205 days after transplanting. Foliar application at estimated concentration of 27.5 and 41.5 μM H2O2 led to the highest values of total titratable acidity and vitamin C, respectively, at 205 DAT. Water salinity above 0.7 dS m-1 resulted in changes in the physico-chemical characteristics of passion fruit. Peroxide concentrations up to 60 μM did not mitigate the deleterious effects of salt stress on passion fruit yield and quality in the first crop cycle.

The addition of citrate stimulates the production of acetoin and diacetyl by a citrate-positive Lactobacillus crustorum strain during wheat sourdough fermentation

In traditional sourdough fermentation recipes of artisan bakeries, often extra ingredients are added to the flour-water mixture. This may accentuate the aroma and taste of the baked products produced from such sourdoughs. This is made possible, for instance, by stimulating certain microbial activities during fermentation. This study examined the effects of the addition of citrate (a food-grade organic acid present in milk and lemons) on wheat sourdough fermentation in the presence of a citrate-positive, homofermentative, lactic acid bacterial starter culture strain, namely Lactobacillus crustorum LMG 23699. Both liquid and firm wheat sourdoughs were produced. The starter culture strain was able to steer all wheat sourdough fermentations performed, as it always prevailed due to its competitiveness, as shown through culture-dependent microbiological plating and culture-independent bacterial community profiling. Moreover, it possessed all enzyme-encoding genes (as unraveled through genome mining) necessary to convert citrate into desirable compounds such as lactic acid, acetic acid, succinate, acetoin, diacetyl, and 2,3-butanediol. Indeed, citrate addition to the wheat flour-water mixture had an impact on the sourdough fermentation dynamics and thus on the aroma profile of the liquid and firm sourdoughs produced and breads made thereof. A higher final pH, higher total titratable acidity values, and low yeast counts were found in wheat sourdoughs produced with citrate. In particular, the starter culture strain added converted the supplemented citrate into more l-lactic acid as well as acetoin and diacetyl (buttery aroma compounds), which was independent of the dough yield. The buttery aroma compounds were also accentuated in the concomitant breads produced. Further, organic acid production was stimulated in the sourdoughs, whereas increased pyrazine concentrations occurred in the breads. Consequently, citrate supplementation to wheat sourdoughs could be of interest to produce baked goods with enhanced buttery aroma compounds and notes.