Influence of fresh Wolffia globosa on the technological parameters of french macarons

Introduction

French macarons are popular Western desserts characterized by their small circular shape, crisp exterior, and soft, moist interior (Campbell & Mougeot, 1999) [8] . Although they originated in Italy, macarons were later refined in France, where they gained widespread recognition and eventually became globally popular (McGee, 2007; Wybauw, 2007) [19,34] . These confections are primarily composed of meringue and almond flour, which together contribute to their distinctive structure and texture (McGee, 2007; Wybauw, 2007) [19,34] . The standard macaron formulation includes egg whites, granulated sugar, powdered sugar, and almond flour (Bissar & Özcan, 2022; Oncicăet al., 2025) [5,25] , with almond powder, egg whites, and sugar identified as the core ingredients critical for successful macaron production (Oncică et al., 2025) [25] . However, macaron production requires highly precise ingredient ratios to maintain characteristic texture and appearance, making ingredient substitution particularly challenging (Bissar & Özcan, 2022) [6] . Wolffia globosa is a nutrient-dense aquatic plant recognized for its high protein content and richness in essential micronutrients (On-Nom et al., 2023) [26] . The incorporation of fresh Wolffia globosa into French macarons offers a promising approach to nutritional enhancement while preserving sensory quality. However, the inclusion of novel ingredients such as Wolffia globosa necessitates careful evaluation of batter rheological behavior and matrix stability to ensure product quality, as alterations in the macaron matrix can significantly influence final product characteristics (Oncică et al., 2025) [25] . Therefore, the objective of the present study was to evaluate the effect of incorporating fresh Wolffia globosa into French macarons on their nutritional composition, antioxidant activity, colour attributes, texture profile, and sensory acceptability, with the aim of developing a Nutritionally enriched, value-added functional macaron without compromising consumer appeal (Campbell & Mougeot, 1999; Appenroth et al., 2018) [4,8] .

Materials and methods

Fresh Wolffia globosa and ingredients

Fresh Wolffia globosa was collected from Wolffia tanks of College of Fisheries, Lembucherra and West Tripura. The ingredients used for the preparation of French macarons included almond flour, powdered sugar, granulated sugar, and egg whites for the macaron shells. For the experimental formulation, fresh Wolffia globosa was incorporated by partially replacing the stiffened meringue. The cream filling was prepared using salted butter, fresh cream, lemon zest, vanilla essence, and vinegar.

Preparation of French Macarons

French macarons were prepared using the French meringue method. Egg whites were whipped until foamy and gradually beaten with granulated sugar to obtain a stiff and glossy meringue. Almond flour and powdered sugar were finely ground, mixed, and sieved to ensure uniform particle size and smooth batter consistency (Table 1).

Optimization of Wolffia globosa to French Macaron

Optimisation was performed for 5, 10 and 15% of incorporation into meringue. However, the 10% was optimised based on the "foot" formation and further to have nutritional enhancement (Fig. 1).

Fig 1:

Observation of foot in the control macaron and 10% wolffia enriched macaron

Preparation and Incorporation of Wolffia globosa

Fresh Wolffia globosa was thoroughly washed with potable water to remove adhering impurities and gently pat-dried to eliminate excess surface moisture. For the experimental formulation, 10% of the stiffened meringue was replaced with fresh Wolffia globosa (19 g replacement in 190 g of meringue). The prepared Wolffia globosa was gently folded into the meringue to avoid collapse of the aerated structure. The schematic diagramme is depicted in Fig. 2.

Fig 2:

Schematic process of preparing the French macarons with and without fresh Wolffia

Macaronage, Piping, and Resting

The almond flour-powdered sugar mixture was incorporated into the meringue (control) and Wolffia-meringue mixture (treatment) using the macaronage technique until a smooth, flowing batter was obtained. The batter was transferred to a piping bag and piped into uniform circular shells (approximately 4 cm diameter) on parchment-lined baking trays. The piped shells were rested at room temperature for 30-40 minutes to allow surface drying and skin formation.

Baking and Filling

Macaron shells were baked in a preheated oven at 150 °C for 14-16 minutes. The Wolffia-incorporated macarons required a slightly longer baking time (~17 minutes) due to higher moisture content. After baking, the shells were cooled to room temperature and filled with cream filling prepared using butter, fresh cream, lemon zest, and vanilla essence.

Influence of fresh Wolffia globosa on the technological quality of French macaron 3.1. Proximate composition analysis

The proximate composition analysis (moisture, crude protein, fat, and ash content) of control and Wolffia-added French Macarons were carried out using the following standard methods of AOAC (2016) [1] .

Assay for antioxidant activity 3.3. 2, 2-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical scavenging activity

Arnao et al. (2001) [5] measured ABTS of control and Wolffia-added French Macarons. The ABTS working solution was prepared by mixing equal volumes of 7.4 mM ABTS and 2.6 mM potassium persulfate, then kept in the dark at room temperature for 12 hours. It was diluted (1 mL ABTS + 60 mL methanol) to obtain an absorbance of 1.1±0.02 at 734 nm. For the assay, 150 µl of sample was mixed with 2,850 µl of ABTS solution and incubated in the dark for 2 hours. Methanol was used as the control.

Absorbance was measured at 734 nm, and ABTS radical inhibition (%) was calculated using the formula.

Where, A0= Absorbance of the control A1= Absorbance of the sample

2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity

The DPPH radical scavenging activity of control and Wolffia-added French Macarons was determined according to Dhanabalan et al. (2017) [11] . The stock solution was prepared by dissolving 24 mg DPPH in 100 mL methanol and stored at -20 °C. The working solution was made by mixing 10 mL of stock with 45 mL methanol. For the assay, 150 μl of diluted sample was mixed with 2850 μl of DPPH solution and kept in the dark for 24 hours. Methanol was used as the control. Absorbance was measured at 515 nm, and inhibition (%) was calculated using the formula.

Where, A0= Absorbance of the control A1= Absorbance of the sample

Colour analysis

The colour of the samples was determined in triplicate using a spectrocolorimeter (Colourflex EZ, Hunter Associates Laboratory, Inc., Reston, VA) with illuminant D65/10°. The instrument was calibrated with black and white reference plates before analysis. A slice of each sample was placed over the light source, and L*, a*, and b* values were recorded. L* represents lightness (0 = black, 100 = white), a* indicates red/green (+a* red, -a* green), and b* indicates yellow/blue (+b* yellow, -b* blue). The CIELAB (L*, a*, b*) colour scale was used (Young and Whittle, 1985) [38] .

Texture Profile Analysis (TPA)

Textural properties of all samples were determined using a texture analyzer (TA-XT PLUS, Stable Micro Systems, Surrey, England, and UK) with a 75 mm compression plate and 50 kg load cell. Samples were cut into 2.5 × 3.0 cm cubes, and three cubes per sample were analyzed. The test conditions were 60% compression, pre-test speed 1 mm s⁻¹, test speed 1 mm s⁻¹, post-test speed -5 mm s⁻¹, distance 8 mm, and trigger force 5 g. Hardness, adhesiveness, cohesiveness, and chewiness were recorded.

Sensory scores

French Macaron samples were conditioned to room temperature and served to students, faculty, and staff of the College of Fisheries, Lembucherra for sensory evaluation. Panelists were briefed on the 9-point Hedonic Scale (Meilgaard et al., 2006) [20] before assessment. They evaluated general appearance, colour, texture, odor, flavour, and overall acceptability on a scale of 1 to 9 (9 = like extremely, 1 = dislike extremely).

Results and discussion

Proximate composition

The incorporation of Wolffia into French macarons resulted in minor but notable changes in their proximate composition and nutritional profile (Table 2). Moisture content showed a slight increase from 7.91% in the control to 8.12% in the Wolffia-added macarons, which may influence the texture, mouthfeel, and shelf stability of the product. Similarly, ash content increased marginally from 0.98% to 1.00%, indicating a possible enrichment of mineral components. This observation is consistent with previous reports that Wolffia species are naturally rich in minerals such as potassium and iron (Appenroth et al., 2018) [4] . A more pronounced change was observed in the protein content, which increased from 9.75% in the control to 10.30% in the Wolffia-fortified macarons (dry weight basis). [23,39] . The increase can be attributed to the naturally high protein content of Wolffia species, which reportedly ranges from 20-30% of freeze-dried weight (Appenroth et al., 2018; Patcharabudsarakumkul et al., 2025) [4,28] .The lipid content remained relatively unchanged, with values of 14.23±0.08% in the control and 14.12±0.74% in the Wolffia-added macarons, indicating that Wolffia incorporation did not significantly alter the fat composition of the product. This finding is in agreement with the relatively low-fat content of Wolffia, reported to range between 1-5% (Appenroth et al., 2018) [4] . Interestingly, the fiber content decreased from 0.60% in the control to 0.41% in the Wolffia-added macarons. This observation contrasts with the general perception of Wolffia as a dietary fiber source, with reported fiber contents of approximately 25% of freeze-dried weight (Appenroth et al., 2018; On-Nom et al., 2023) [4] . The reduction in measured fiber content may be attributed to factors such as the level of Wolffia incorporation, the specific form of Wolffia used, or interactions between ingredients during processing that could influence fiber determination. [17,35] . The presence of such pigments is known to influence the visual characteristics of food products and can significantly alter their appearance during processing and baking (Molina et al., 2023; Wijesekara & Xu, 2024) [21,32] . Similar observations have been reported in studies involving the incorporation of plant-and algae-based ingredients into bakery and snack products, where reductions in lightness and increases in yellowness or redness were commonly observed depending on the concentration and type of ingredient used (Gharehbeglou et al., 2023; Yilmaz & Yücetepe, 2022) [17,37] . The observed changes in color are important from a product development perspective, as visual appearance strongly influences consumer perception, acceptance, and expectations regarding quality, freshness, and nutritional value (Famakinwa et al., 2023; Wadhera & Capaldi-Phillips, 2014) [14,31] . Although some studies on Wolffia-fortified snack products have reported minimal changes in color (On-Nom et al., 2023), the present findings suggest that Wolffia incorporation at the selected level had a pronounced effect on the appearance of French macarons. Therefore, optimizing the incorporation level of Wolffia may be important to balance improved nutritional functionality with desirable sensory characteristics and consumer acceptability (Daszkiewicz et al., 2023; Wu et al., 2024) [10,33] . [2,3,12,24] . The observed changes suggest that the addition of Wolffia significantly modified the structural integrity of the macaron matrix. The increase in texture firmness may be attributed to the protein and fiber components present in Wolffia. Plantbased ingredients rich in proteins and dietary fibers are known to interact with starches and proteins within food systems, resulting in the formation of denser and more rigid networks that reduce water mobility and increase structural compactness (Flory et al., 2023; Fratelli et al., 2023) [15,16] . Similar findings have been reported in bakery products fortified with microalgae such as Chlorella vulgaris, where increased hardness and reduced softness were associated with the formation of a stiffer dough matrix (Dündar et al., 2023) [13] . The relatively high protein content of Wolffia (Appenroth et al., 2018; On-Nom et al., 2023) [4] may have contributed to the development of stronger internal interactions within the macaron structure, thereby increasing hardness and cohesiveness. The increase in cohesiveness suggests improved internal bonding within the product matrix, while the higher resilience indicates a greater capacity of the macarons to recover after deformation (Alemu, 2023; Dou et al., 2023) [2,12] . However, the slight reduction in springiness reflects a decrease in elasticity, indicating that the Wolffia-added macarons became less flexible despite being structurally stronger. These textural modifications are particularly important because texture is a major sensory attribute influencing consumer acceptance and eating quality (Giron et al., 2025; Nasrollahzadeh et al., 2024) [18,22] . The substantial increase in hardness, gumminess, and chewiness may alter the characteristic delicate, soft, and airy texture traditionally associated with French macarons, which could influence consumer preference and overall acceptability. Therefore, optimization of the incorporation level of Wolffia may be necessary to achieve a balance between enhanced nutritional functionality and desirable sensory properties. [17,35] . Although these pigment-related changes slightly affected color preference, the appearance score of the fortified macarons was higher (approximately 8.4) than that of the control (7.8), suggesting that consumers found the product visually appealing despite the color modification (Bordim et al., 2021) [7] . Aroma and flavor scores also improved following Wolffia incorporation, with aroma increasing from approximately 7.6 in the control to 8.2 in the fortified macarons, and flavor increasing from around 7.0 to 8.4. These findings indicate that the addition of Wolffia enhanced the sensory quality of the macarons without imparting undesirable off-flavors, thereby contributing positively to consumer acceptability (Rabitti et al., 2024) [29] .

Texture received the highest improvement among all sensory attributes, increasing from approximately 7.2 in the control to 8.6 in the Wolffia-added macarons. This enhanced texture perception may be associated with the increased firmness, cohesiveness, and chewiness observed during texture profile analysis, which likely contributed to a more desirable mouthfeel and eating experience ( [15,16,18,22] . The sensory evaluation results demonstrate strong consumer acceptance of Wolffiafortified French macarons. Despite slight changes in color, the improvements observed in aroma, flavor, texture, and appearance suggest that Wolffia has considerable potential as a functional ingredient for developing nutritionally enriched confectionery products with desirable sensory characteristics (Chala & Emire, 2022; Siegrist & Hartmann, 2020) [9,30] .

Fig 3: Radar chart illustrates sensory evaluation

Conclusion

The present study demonstrated that incorporation of 10% fresh Wolffia globosa is optimal for the development of nutritionally enriched macarons without compromising product quality. Macarons formulated at this level exhibited well-defined feet, uniform shape, and good rise, indicating effective protein network formation and proper steam expansion during baking. Texture profile analysis confirmed a desirable crisp outer shell with a soft interior, comparable to control macarons. Although a slight green hue was observed due to Wolffia addition, the colour remained visually acceptable and did not adversely influence consumer perception. Proximate composition analysis revealed enhanced protein content along with improved antioxidant activity, highlighting the nutritional advantage of Wolffia incorporation. Sensory evaluation using a 9-point hedonic scale indicated good acceptability across taste, texture, appearance, and overall quality. Overall, the study supports the potential of Wolffia globosa as a functional ingredient for developing nutrient-enriched macarons with satisfactory technological and sensory attributes.

Acknowledgement

AcknowledgmentsThe authors express their sincere gratitude to the Dean, College of Fisheries, Central Agricultural University (Imphal), for providing the necessary facilities, encouragement, and institutional support to carry out this student research project successfully. The authors also acknowledge the support extended by the Department of Aquaculture for providing fresh Wolffia globosa used in the study under the project (BT/PR41748/NER/95/1862/2021; Scheme: I&ED; 0155).

References

1. AOAC International. Official Methods of Analysis of AOAC International. 20th ed. Rockville (MD): AOAC International; 2016.
2. Alemu T. Texture profile and design of food product. J Agric Hortic Res. 2023;6:272-281.
3. Altan CO, Kocatepe D, İpar MS, Çorapçı B, Köstekli B, Turan H. The effect of microbial transglutaminase (MTGase) enzyme on physical, sensorial and nutritional properties of Atlantic salmon (Salmo salar Linnaeus, 1758) meatballs. J Agric Fac Gaziosmanpaşa Univ. 2023;40(1):41-49.
4. Appenroth KJ, Sree KS, Bog M, Ecker J, Seeliger C, Böhm V, et al. Nutritional value of the duckweed species of the genus Wolffia (Lemnaceae) as human food. Front Chem. 2018;6:483.
5. Arnao MB, Cano A, Acosta M. The hydrophilic and lipophilic contribution to total antioxidant activity. Food Chem. 2001;73(2):239-244.
6. Bissar S, Özcan MM. Determination of quality parameters and gluten-free macaron production from carob fruit and sorghum. Int J Gastron Food Sci. 2022;27:100460.
7. Bordim J, Lise CC, Marques C, Oldoni TC, Varela P, Mitterer-Daltoé ML. Potential use of naturally colored antioxidants in the food industry: a study of consumers' perception and acceptance. J Sens Stud. 2021;36(4):e12678.
8. Campbell GM, Mougeot E. Creation and characterisation of aerated food products. Trends Food Sci Technol. 1999;10(9):283-296.
9. Chala DB, Emire SA. Development of plant-based functional food products: a review. Ann Univ Dunarea Jos Galati Fascicle VI Food Technol. 2022;46(1):169183.
10. Daszkiewicz T, Florek M, Wodzak M, Kubiak D, Burczyk E. Comparison of the quality of selected meat products and their plant-based analogs. Pol J Food Nutr Sci. 2023;73(2):109-119.
11. Dhanabalan V, Xavier M, Kannuchamy N, Asha KK, Singh CB, Balange A. Effect of processing conditions on degree of hydrolysis, ACE inhibition, and antioxidant activities of protein hydrolysate from Acetes indicus. Environ Sci Pollut Res. 2017;24(26):2122221232.
12. Dou X, Lv M, Ren X, He Y, Zhang G, Sun Y, et al. Test conditions of texture profile analysis for frozen dough. Ital J Food Sci. 2023;35(4):58-68.
13. Dündar AN, Şahin OI, Sarıcaoğlu FT. Low-fat cookies with Chlorella vulgaris: effects on dough rheology, physical, textural and sensory properties of cookies. Gıda J Food. 2023;48(3):526-544.
14. Famakinwa A, Shuttleworth A, Lubisi S, Olubi O, Oguntibeju OO, Obilana AO. Chemical and functional properties of snacks produced from wheat flour fortified with Moringa oleifera leaf powder. Afr J Food Agric Nutr Dev. 2023;23(9):24467-24486.
15. Flory J, Xiao R, Li Y, Dogan H, Talavera MJ, Alavi S. Understanding protein functionality and its impact on quality of plant-based meat analogues. Foods. 2023;12(17):3232.
16. Fratelli C, Nunes MC, De Rosso VV, Raymundo A, Braga ARC. Spirulina and its residual biomass as alternative sustainable ingredients: impact on the rheological and nutritional features of wheat bread manufacture. Front Food Sci Technol. 2023;3:1258219.
17. Gharehbeglou P, Homayouni-Rad A, Jafari SM, Sarabandi K, Akbarbaglu Z. Stabilization of Chlorella bioactive hydrolysates within biopolymeric carriers: techno-functional, structural, and biological properties. J Polym Environ. 2024;32(2):763-779.
18. Giron M, Oosterlinck F, Steenhorst-Slikkerveer L, Francois O, Peyron MA. Comparison of granulometric and textural characteristics of in vitro food bolus of beef-and plant-based patties. Food Hydrocoll. 2025;163:111071.
19. McGee H. On Food and Cooking: The Science and Lore of the Kitchen. New York: Simon & Schuster; 2007.
20. Meilgaard MC, Carr BT, Civille GV. Sensory Evaluation Techniques. 4th ed. Boca Raton (FL): CRC Press; 2006. p. 156.
21. Molina AK, Corrêa RC, Prieto MA, Pereira C, Barros L. Bioactive natural pigments' extraction, isolation, and stability in food applications. Molecules. 2023;28(3):1200.
22. Nasrollahzadeh F, Alexi N, Skov KB, Roman L, Sfyra K, Martinez MM. Texture profiling of muscle meat benchmarks and plant-based analogues: an instrumental and sensory design approach with focus on correlations. Food Hydrocoll. 2024;151:109829.
23. Nitiwuttithorn C, Wongsasulak S, Vongsawasdi P, Yongsawatdigul J. Effects of alkaline and ultrasonication on duckweed (Wolffia arrhiza) protein extracts' physicochemical and techno-functional properties. Front Sustain Food Syst. 2024;8:1343615.
24. Nwosisi S, Nandwani D, Ravi R. Texture profile analysis of organic sweetpotato (Ipomoea batatas) cultivars as affected by different thermal processing methods. Int J Agric Environ Food Sci. 2019;3(2):93100.
25. Oncică FG, Stoica F, Constantin OE, Andronoiu DG, Aprodu I, Ratu RN, et al. Phytochemical composition and sensory acceptability of macarons supplemented with carrot pomace. Ann Univ Dunarea Jos Galati Fascicle VI Food Technol. 2025;49(1):9-26.
26. On-Nom N, Promdang P, Inthachat W, Kanoongon P, Sahasakul Y, Chupeerach C, et al. Wolffia globosabased nutritious snack formulation with high protein and dietary fiber contents. Foods. 2023;12(14):2647.
27. Pagliuso D, Jara CEP, Grandis A, Lam E, Ferreira MJP, Buckeridge MS. Flavonoids from duckweeds: potential applications in the human diet. RSC Adv. 2020;10(73):44981-44988.
28. Wimm.) and rice protein isolate powders using an Ioptimal design: enhanced protein content and functional properties. Front Sustain Food Syst. 2025;9:1661446.
29. Rabitti NS. Consumer Perception and Preference of Plant-Based Sustainable Food Ingredients [dissertation]. Department of Food, Nutrition and Environmental Sciences; 2024. Available from: https://hdl.handle.net/2434/1040209
30. Siegrist M, Hartmann C. Perceived naturalness, disgust, trust and food neophobia as predictors of cultured meat acceptance in ten countries. Appetite. 2020;155:104814.
31. Wadhera D, Capaldi-Phillips ED. A review of visual cues associated with food-on-food acceptance and consumption. Eat Behav. 2014;15(1):132-143.
32. Wijesekara T, Xu B. A critical review on the stability of natural food pigments and stabilization techniques. Food Res Int. 2024;179:114011.
33. Wu H, Sakai K, Zhang J, McClements DJ. Plant-based meat analogs: color challenges and coloring agents. Food Nutr Health. 2024;1(1):4-15.
34. Tielt (Belgium): Lannoo Uitgeverij; 2007.
35. Yadav NK, Patel AB, Debbarma S, Priyadarshini MB, Priyadarshi H. Characterization of bioactive metabolites and antioxidant activities in solid and liquid fractions of fresh duckweed (Wolffia globosa) subjected to different cell wall rupture methods. ACS Omega. 2024;9(18):19940-19955.
36. Yadav NK, Patel AB, Priyadarshi H, Baidya S. Salinity stress-induced impacts on biomass production, bioactive compounds, antioxidant activities and oxidative stress in watermeal (Wolffia globosa). Discov Appl Sci. 2025;7(2):106.
37. Yılmaz M, Yücetepe A. Investigation of changes in antioxidant activity and protein digestibility of wheat breads including Spirulina platensis and protein extracts from Spirulina platensis during in vitro digestion. Gıda J Food. 2022;47(5):776-789.
38. Young KW, Whittle KJ. Colour measurement of fish minces using Hunter L, a, b values. J Sci Food Agric. 1985;36(5):383-392.
39. Zięć G, Michalski O, Konieczna-Molenda A, Dera T, Tkaczewska J. Nutritional value, health properties, safety considerations, and consumer acceptance of Lemnoideae as human food. Nutrients. 2025;17(18):3026.