Effect of grape pomace usage in chocolate spread formulation on textural, rheological and digestibility properties

Production of low-protein cocoa powder with enzyme-assisted hydrolysis

Amino acid-related disorders are caused by a defect in the metabolic pathways of amino acid groups. These patients must follow a lifelong protein diet. The objective of this study was to produce a low-protein cocoa powder (LPP) with enzymatic hydrolysis and precipitation method. First, the solubility of cocoa powder was increased by heat and enzyme treatments (Amylase, Viscozyme, and Alcalase). Then, the protein level was decreased by isoelectric precipitation. According to the obtained results, the solubility of cocoa powder rose from 28.61% to 50.69%. Protein content decreased by almost 40% and significant reductions in the amino acid profile were also provided; the highest ones were detected in methionine (100%), lysine (73.65%), leucine (53.64%), alanine (46.17%), and isoleucine (44.73%) levels. LPP had high phenolic content (25.10 mg/g GAE) and the changes in the antioxidant activities were not significant (p > .05). Moreover, chocolate production with LPP and control powder was also carried out under laboratory conditions. Hardness (1732.52 g), moisture content (0.60%), and water activity (0.37) of chocolate samples produced with low-protein cocoa powder (LPC) were lower than those of the control sample. The Casson model well fitted to the rheological data (R 2 > .990) and chocolate samples showed elastic behavior. The removal of proteins from the cocoa was verified with Fourier transform infrared spectroscopy analyses. The melting temperatures of chocolates (31.84 and 31.54°C for control and LPC samples, respectively) did not change with the applied process. As a conclusion, it was revealed that the production of low-protein cocoa powder and chocolate is feasible for patients with amino acid disorders with this study.

Textural, rheological, melting properties, particle size distribution, and NMR relaxometry of cocoa hazelnut spread with inulin-stevia addition as sugar replacer

This study investigated the influence of substituting 60, 80, and 100% of the sugar in traditional cocoa hazelnut paste (control) formulation with inulin-stevia (90:10, w/w) mixture on textural and rheological characteristics, melting behavior, water activity (aw), particle size distribution (PSD), and color. Textural, rheological, melting properties, and color of samples were analyzed after 1, 2, and 3 months of storage at 11°C. Nuclear magnetic resonance (NMR) relaxometry experiments were also performed to understand the interaction of new ingredients with oil. Replacement of sugar with inulin-stevia gave darker color, reduced Casson yield stress, and changed the textural parameters and melting profile of the samples depending on the level but did not create a remarkable effect on PSD and Casson plastic viscosity. Increasing inulin-stevia content yielded lower aw and higher T2a values indicating decreased mobility of water. Complete removal of sugar caused low spreadability. The results showed that an 80% replacement level yielded a product with similar textural parameters and fat-melting mouth feeling compared to control sample. Cocoa hazelnut spreads prepared with inulin and stevia showed good textural stability during storage.

Characterization of acorn oil and its application on carnauba wax-based oleogel and chocolate spread

This study aimed to characterize acorn oil (AO) and carnauba wax-based acorn oil oleogel (AOG) and the effect of AOG replacement on the textural and sensorial properties of chocolate spread. Oil yields from cold-pressing (Quercus longipes) were around 14%wt with a nice nutty smell. The main fatty acids of AO were included oleic, linoleic, and palmitic acid (44, 38, and 10%wt) respectively. The prepared AOG using 6%wt of carnauba wax (CW) showed high strength (G' > 100 mPa) and oil binding capacity ∼87 %. Based on microstructure assays platelet-like and β' polymorphic triglyceride crystalline networks were formed in AOG. The Pickering AOG/water emulsions in the volumetric ratio of from 90:10 up to 40:60 were stable due to the placement of CW-based AOG particles at the interface of water/oil as Pickering stabilizer. The high physical stability of the emulgel against phase separation is considered an important advantage for using oleogel in chocolate spread formulations instead of vegetable oils, which usually have a high percentage of oil release. The spreads prepared by replacing 50%wt AOG with butter showed acceptable textural and sensorial properties.

Dark-Chocolate-Coated BRS Clara Raisins: Phenolic Composition and Sensory Attributes

Dark chocolate dragée confectionary was made with BRS Clara raisins pre-treated with extra virgin olive oil (EVOO). The evaluation of the changes in the phenolic composition (flavonols, hydrocinnamic acid derivatives (HCADs), stilbenes and flavan-3-ol monomers, dimers, and proanthocyanidins (PAs)) resulting from the covering process showed that the chocolate coating was responsible for an increase in the concentrations of flavan-3-ols and PAs when compared to just the raisins. For the flavonols and HCADs, a reduction in the total concentration of compounds was observed when comparing the dragées to the raisins. Furthermore, there was a strong influence of chocolate in the qualitative profile with the emergence of new compounds (quercetin-3-pentoside, kampfterol-3-rutinoside, p-coumaric acid, and caffeoyl-aspartate). The combination of these ingredients (raisins and chocolate) resulted in a dark chocolate coated raisin (DC) with good sensory acceptance and a more complex phenolic composition that may positively contribute to its functional quality.

Investigation of Antioxidant and Cytotoxicity Activities of Chocolate Fortified with Muscadine Grape Pomace

Muscadine grape pomace and mixed products with chocolate extracts from three muscadine genotypes exhibiting different berry skin colors (black and bronze) were investigated for total phenolic content (TPC), total flavonoid content (TFC), DPPH, FRAP antioxidant activity, and anticancer activity using MDA-MB-468 (MM-468; African American) breast cancer cells. Muscadine berry extracts and mixed products showed cytotoxicity activities of up to 70% against MM-468 breast cancer cells. Cell growth inhibition was higher in 'macerated Floriana' with an IC50 value of 20.70 ± 2.43 followed by 'Alachua' with an IC50 value of 22.25 ± 2.47. TPC and TFC in macerated MGP powder were (1.4 ± 0.14 and 0.45 ± 0.01 GAE/g FW, respectively), which was significantly higher than those in cocoa powder. Data analysis showed a high association between DPPH, FRAP antioxidant activities, and TPC content and a positive high correlation between anticancer activity and antioxidant capacity and between TPC and anticancer activity. The anticancer and antioxidant effects of muscadine grape pomace and chocolate extracts are attributed to the TPC of extracts, which showed a stronger positive correlation with growth inhibition of African American breast cancer cells. This study would be of great value for food industries as well as other manufacturers who are interested in new food blends.

Upcycling flavanol-rich Chardonnay and Pinot noir grape thinned clusters as potentially functional food ingredients in cocoa-based products

In California, over 3.4 million tons of wine grapes were crushed in 2020 while every year roughly 20% of the grape mass goes unused. Grape cluster thinning at veraison, a common agricultural practice to ensure color homogeneity in wine grapes, adds to the production costs and generates substantial on-farm loss during grapevine cultivation in which the health-promoting values of thinned clusters (unripe grapes) are usually overlooked. In particular, the health-promoting properties of flavanol monomers, specifically (+)-catechin and (-)-epicatechin, and their oligomeric procyanidins, have been extensively studied in cocoa and chocolate but not so much in grape thinned clusters in recent epidemiology studies. As part of the important agricultural by-products upcycling effort, the current study compared thinned clusters from Chardonnay and Pinot noir, two premium wine grape varieties cultivated in California, to a traditionally Dutch (alkalized) cocoa powder that has been widely used in food applications. Thinned cluster fractions from Chardonnay and Pinot noir grapes grown in the North Coast of California showed much higher concentrations of flavanol monomers and procyanidins, with 208.8-763.5 times more (+)-catechin, 3.4-19.4 times more (-)-epicatechin, and 3.8-12.3 times more procyanidins (by degree of polymerization DP 1-7) than those in the traditionally Dutch cocoa powder. These flavanol-rich thinned clusters that are also considered as plant-based natural products suggested great potential to be functional ingredients in cocoa-based products-which have been ubiquitously perceived as flavanol-rich products by consumers-to enhance their overall dietary flavanol content.

Sustainability on Bread: How Fiber-Rich Currant Pomace Affects Rheological and Sensory Properties of Sweet Fat-Based Spreads

Dietary fiber may contribute to increasing the nutritional value of “unhealthy food”—for instance, spreads with high fat and sugar content. The high amount of fiber and the presence of phenolic compounds, organic fruit acids, and aroma compounds make currant pomace a promising ingredient to be used in a wide range of foods. However, the particle size of this by-product is a key factor influencing texture, rheology, physical stability, and sensory properties of the final commodities. Wet planetary ball milling of seedless currant pomace suspended in oil resulted in particles <30 µm, which is required for a creamy texture. Spread stiffness and viscosity were adapted by lowering the solid fat content in a way that the fruity spreads with 16 g/100 g pomace resembled a sweet commercial nut spread. The pomace showed stabilizing effects, as oil separation was reduced and a viscosity increase during storage was prevented. Principal component analysis after sensory flash profiling of five formulations highlighted differences in fruitiness, sweetness, greasiness, and viscosity. Hence, depending on the pomace level and fat composition in the formulation, the properties of sweet spreads can be specifically designed to fulfill the respective requirements. Additionally, sweet and savory wafer fillings provide great potential to be enriched with fruit pomace.

Effect of infrared drying on chemical and microbial properties of Cold‐Hardy grape pomace (Edelweiss and Marquette)

This study aims to add value to a common wine industry waste by preserving bioactive compounds in cold-hardy grape pomace (GP) and preventing any microbial growth under the proper drying conditions. Effects of infrared (IR) and hot air (HA) drying on the microbial and physicochemical properties such as color, phenolic compounds, and antioxidant activity of white (Edelweiss) and red (Marquette) GP were studied. The IR heating rapidly reduced the moisture content of GP from 55% wet basis (w.b.) to less than 10%, which resulted in a drying time reduction of 71.9% to 80.2% compared to HA drying. There were no significant differences in color parameters among the IR- and HA-dried pomaces (p > .05). The phenolic content of 'Edelweiss' pomace was not significantly affected by both IR and HA drying, whereas the phenolic content of 'Marquette' pomace was substantially reduced from 274 mg/g dry extract in raw pomace to 127 mg/g dry extract after HA drying and to 141.9 mg/g dry extract after IR drying. Overall, the microbial load on the fresh pomace samples was dramatically reduced by IR heating, with a reduction of more than 99.9% when the pomaces were dried using IR at a temperature higher than 130°C. However, this high temperature of IR led to a significant reduction of DPPH antiradical scavenge activity for 'Edelweiss' pomace (p < .05). This study shows that using the IR approach, cold-hardy 'Edelweiss' and 'Marquette' grape pomaces can be efficiently dried with the antioxidant activity maintained, which could be used in a variety of food products as a functional ingredient.

Physical and Chemical Properties of 70% Cocoa Dark Chocolate Mixed with Freeze-Dried Araz&aacute; (Eugenia stipitata) Pulp

This work aimed to determine the chemical and physical properties of 70% dark cocoa chocolate, including freeze-dried Arazá (Eugenia stipitata) pulp (FDAP). We studied chocolates incorporating three FDAP concentrations (1.0, 1.5, and 2.0%). No statistical differences were found in total polyphenol content, antioxidant capacity, and total catechin and epicatechin content. The dark chocolates' moisture and texture were unaffected by the FDAP. The Casson yield stress increased to 19.67±1.35 Pa, while the Casson plastic viscosity reduced to 1.68±0.03 Pa·s, Also, the particle size increased. The dark chocolates' flow behavior corresponded to a non-Newtonian fluid. Finally, the dark chocolate's properties were unaffected by a 2% FDAP concentration.

The Wine Industry By-Products: Applications for Food Industry and Health Benefits

Each year, 20 million tons of wine by-products are generated, corresponding to 30% of the total quantity of vinified grapes. Wine by-products are a source of healthy bioactive molecules, such as polyphenols and other molecules (pigments, fibers, minerals, etc.). The abundance of bioactive compounds assures a promising future for nutritional foodstuff production. Wine by-products can be used to fortify aromatized waters and infusions, bread, pasta, dairy products, alcohol, sugary beverages, and processed foods. These innovative products are part of the Mediterranean diet and are of great interest to both human and environmental health. Pre-clinical studies show that consumption of food produced with wine by-products or with their extracts attenuates the inflammatory state and increases antioxidant status. As such, wine by-products provide protective effects against the underlying pathophysiological hallmarks of some chronic diseases such as atherosclerosis, diabetes, hypertension, obesity, and cancer. However, the poor bioavailability warrants further investigation on how to optimize the efficacy of wine by-products, and more clinical trials are also needed. The scientific evidence has validated the uses of the dietary nature of wine by-products and has helped to promote their use as a functional food to prevent chronic human diseases.

Cocoa Spread with Grape Seed Oil and Encapsulated Grape Seed Extract: Impact on Physical Properties, Sensory Characteristics and Polyphenol Content

The aim of this study was to utilize grape pomace, as a polyphenol-rich by-product of wine production, in the manufacture of enriched cocoa spread. The formulation of the cocoa spread has been modified by substitution of refined sunflower oil with cold-pressed grape seed oil. The spread with grape seed oil (Cg) was further enriched with grape seed extract encapsulated on maltodextrins (E), where 10% and 15% of E was added to Cg obtaining the samples Cg10 and Cg15. The results showed an increase in volume-weighted mean in spread samples, from 19.17 μm in Cg to 19.71 μm in Cg10 and 21.04 μm in Cg15. Casson yield stress and Casson viscosity significantly (p ˂ 0.05) increased from 16.41 Pa and 1.58 Pa·s in Cg to 29.45 Pa and 5.70 Pa·s in Cg15 due to the reduction of the fat-phase content in enriched spreads. The addition of E had no significant effect on the melting temperature (Tpeak) of the enriched spreads, while increasing the amount of E significantly (p ˂ 0.05) increased their hardness. The incorporation of grape seed oil in the cocoa spread formulation contributed to an increase in total polyphenols and flavonoids. Moreover, the addition of 10% and 15% of E to Cg resulted in approximately 1.5× and 2× higher content of phenolic compounds in Cg10 and Cg15 compared to control spread with sunflower oil (Cs). Flavonoids increased from 0.43 mg CE/g in Cs to 0.74 mg CE/g in Cg 10 and 1.24 mg CE/g in Cg15. Encapsulates positively affected sensory characteristics of enriched spread samples by reducing their grape seed oil aroma and sweetness.

Modelling and Optimization of the Processing of a Healthy Snack Bar Made of Grape and Tomato Pomaces

A snack made of 36% by byproducts of grape and tomato pomaces was developed, also including other ingredients, such as oats, chia, quinoa, honey and peanut butter. The recipe was defined as tasty and healthy by a focus group. The snack was produced by using forced air at three different drying temperatures (50 °C, 60 °C and 70 °C). The Newton, Page, Henderson and Pabis, and Midilli–Kucuk models fit the drying curves well. The average values for the Newton’s model drying constants were k₅₀ = 2.71 × 10⁻¹ ± 3 × 10⁻³ min⁻¹, k₆₀ = 2.76 10⁻¹ ± 4 × 10⁻³ min⁻¹ and k₇₀ = 3.91 × 10⁻¹ ± 8 × 10⁻³ min⁻¹ at 50 °C, 60 °C and 70 °C, respectively. The product’s quality was assessed in terms of storage with respect to water activity and texture (hardness, springiness, cohesiveness, chewiness and resilience). There were no differences among the three tested processing temperatures in terms of their influence the final product’s quality. As there were no significant differences between initial and final water activity and texture attributes at any temperature and they were mainly unaltered during storage, the snack bar was considered stable during this period. This new snack, which includes byproducts from the food industry, reduces food waste and contributes to a circular economic model, simultaneously presenting environmental and economic advantages.

Fruit Juice Industry Wastes as a Source of Bioactives

Food processing sustainability, as well as waste minimization, are key concerns for the modern food industry. A significant amount of waste is generated by the fruit juice industry each year. In addition to the economic losses caused by the removal of these wastes, its impact on the environment is undeniable. Therefore, researchers have focused on recovering the bioactive components from fruit juice processing, in which a great number of phytochemicals still exist in the agro-industrial wastes, to help minimize the waste burden as well as provide new sources of bioactive compounds, which are believed to be protective agents against certain diseases such as cardiovascular diseases, cancer, and diabetes. Although these wastes contain non-negligible amounts of bioactive compounds, information on the utilization of these byproducts in functional ingredient/food production and their impact on the sensory quality of food products is still scarce. In this regard, this review summarizes the most recent literature on bioactive compounds present in the wastes of apple, citrus fruits, berries, stoned fruits, melons, and tropical fruit juices, together with their extraction techniques and valorization approaches. Besides, on the one hand, examples of different current food applications with the use of these wastes are provided. On the other hand, the challenges with respect to economic, sensory, and safety issues are also discussed.

Formulating and studying compound chocolate with adding dried grape pomace as a bulking agent

The use of dried grape pomace (DGP) as a bulking agent for partly substitution of sugar, milk powder and whey powder in compound chocolate (CC) was investigated. D-optimal mixture design was used to determine the effect of composition on the particle size, flow behaviour (Casson yield value and plastic viscosity), as well as total phenolic and resveratrol contents before and after in vitro digestion. The various models (linear, quadratic and cubic) which were identified as significant (P < 0.05) were used in this study. As a result, DGP was found suitable to be used in CC as a bulking agent to partially substitute sucrose, milk powder and whey powder to increase functional properties and decrease the cost of the CC. For CC with the most acceptable rheological properties and a satisfactory level of TPC and resveratrol, optimum usage levels of DGP were identified as 7.1% to 10.0%. Further studies will require to modify flow behaviours by optimizing the particle size of pomace.

Enhancing Phenolic Content of Medicinal Aromatic Plants Extracts-Biofunctional Foods Preparation

In this study, the assessment of TPC and antioxidant activity enhancement of medicinal and aromatic plant (MAP) aqueous extracts using natural sweeteners or encapsulation materials was carried out. MAP extracts fortified with polyphenols were used to produce biofunctional chocolate bites. Honey or erythritol added to Melissa officinalis concentrated aqueous extracts exhibited TPC at 19.53 mg GAE/mL and 18.24 mg GAE/mL, respectively, and DPPH radical scavenging activity greater than 82%, comparing to its non-concentrated aqueous extract (3.74 mg GAE/mL and 72.9%, respectively). Honey added to MAP concentrated aqueous extract mixtures presented up to twofold higher TPC compared to M. officinalis concentrated aqueous extracts with honey. Chocolate bites with MAP concentrated aqueous extract mixtures and honey exhibited TPC and DPPH radical scavenging activity at 29.48 mg GAE/g chocolate and 93.7%, respectively. The addition of gum arabic or inulin in MAP concentrated aqueous extract mixtures increased the TPC up to 12-fold (40.37 mg GAE/mL and 34.14 mg GAE/mL, respectively) compared to its non-concentrated aqueous extracts (3.38 mg GAE/mL), whereas DPPH radical scavenging activity approached 99.5%. Honey incorporation as a sweetener and polyphenolic compound encapsulation in gum arabic can lead to the production of biofunctional foods with elevated cytoprotective action without compromising their organoleptic attributes.

Dietary Fiber and Prebiotic Compounds in Fruits and Vegetables Food Waste

The fruits and vegetables processing industry is one of the most relevant food by-products, displaying limited commercial exploitation entailing economic and environmental problems. However, these by-products present a considerable amount of dietary fiber and prebiotics with important biological activities, such as gut microbiota modulation, lowering the glycemic load and replacing some unhealthy ingredients with an impact on food texture. Therefore, the international scientific community has considered incorporating their extracts or powders to preserve or fortify food products an area of interest, mainly because nowadays consumers demand the production of safer and health-promoting foods. In the present review, literature, mainly from the last 5 years, is critically analyzed and presented. A particular focus is given to utilizing the extracted dietary fibers in different food products and their impact on their characteristics. Safety issues regarding fruits and vegetables wastes utilization and anti-nutritional compounds impact were also discussed.

Physico-chemical and sensory acceptability of no added sugar chocolate spreads fortified with multiple micronutrients

Vitamin D and magnesium-calcium carbonate nanoparticles were used to fortify a newly developed healthy chocolate spread formulated with inulin and maltitol as sugar replacers and alternative to palm oil to reduce the concentration of saturated fatty acid. These samples were compared with well-known commercially available chocolate spreads in terms of rheology, polyphenols content and in vitro digestion, sensory attributes and willingness to buy. The fortified chocolate spreads showed comparable if not better acceptability than the current products on the market and over 80% of the participants were inclined to buy and 66% prepared to spend 10 to 15% more money on the product enriched with the three micronutrients. The results also demonstrate that the incorporation of nanoparticles could affect the rheological and physio-chemical properties of the formulations and an appropriate ratio between the fat phase and particles seems an important factor to consider.

Grape pomace as a promising source of biologically valuable components

Experimental data on the content of biologically valuable components in grape pomace are presented. The presence of organic acids was revealed in an amount from 33.35 g/kg (Saperavi) to 108.2 g/kg (Rebo). The main acid is tartaric. Phenolic compounds have been identified: anthocyanins, flavones, flavan-3-ols, oxycinnamic and hydroxybenzoic acids, procyanidins. The main anthocyanins found in grape pomace are the 3-O-glycosides of malvidin, petunidin, cyanidin, peonidin and delphinidin. The highest total content of hydroxybenzoic acids was in the pomace of Pinot Noir grapes – 720 mg/kg, further in descending order of concentration followed by pomace from Saperavi grapes (708 mg/kg), Cabernet Sauvignon (681 mg/kg), Merlot (575 mg/kg) and Rebo (545 mg/kg). The highest total content of vitamins was found in the pomace of Rebo grapes – 639 mg/kg, the lowest – Merlot (471 mg/kg). In all samples, vitamin B1 prevails, then in decreasing order – ascorbic acid, vitamins B2, B3, B5, B7. Moreover, their concentrations vary significantly depending on the grape variety from which the pomace is obtained. The influence of the grape variety on the content of these biologically valuable components in the pomace has been established, which must be taken into account in the production of biologically active substances that increase the nutritional status of a person.