Technologies for Adding Value to Andean Maize Production in the Province of Jujuy, Argentina ^†

Abstract

Andean maize (Zea mays), originating from its wild ancestor, teosinte (Zea mays ssp. parviglumis) in Mexico, has been crucial to the development of diverse civilizations. There are no records of wild maize in northwestern Argentina; the earliest are microfossils found in grinding tools, dating between 3000 and 2600 BC. Jujuy has the greatest number of Andean maize varieties due to its favorable agro-ecological conditions. However, maize is primarily marketed as grain, which limits its use. Revaluing ancestral technologies such as roasting, nixtamalization, and fermentation, alongside modern methods like extrusion, is crucial for enhancing the techno-functional properties of these native grains and preventing biodiversity loss. This study aims to enhance regional maize production, adding value by applying scientific knowledge that supports the development of healthy foods, preserving their original quality, and contributing to the conservation of biodiversity. This initiative seeks to improve the quality of life of the regional population and reinforce its cultural identity.

1. Introduction

Andean maize is one of the most representative crops in Latin America, with a long history of domestication. Mexico is the region of origin, domestication, and diversification of maize (Zea mays L.) with teosinte (Zea mays ssp. Parviglumis) as its ancestor [1,2]. In the NOA there are no records of wild ancestors of maize; the first records correspond to microfossils (phytoliths and starch granules) from grinding tools in the Puna, dated between 3000 and 2600 BC [3]. Currently, in the NOA, production is small-scale, occurring in valleys and ravines in high-altitude areas under agro-ecological conditions that support the conservation of a wide genetic diversity. Jujuy Province has the greatest variety of Andean maize, serving as an in situ germplasm bank. Most of the harvest is marketed as grain, which limits the economic benefits for family farmers and indigenous communities. Its cultural value is reflected in its presence in traditional foods, ceremonies, and rituals. However, in recent years, regional gastronomy has been displaced by foreign industrial products, leaving many maize-based foods, beverages, and ancestral technologies behind. This shift in dietary patterns has negatively impacted the nutritional status of children and adults [4]. Studying and sharing the properties of these native grains promotes their use in making healthy gluten-free foods, adding value to local cuisine. Moreover, revalorizing technologies such as roasting, nixtamalization, and fermentation is essential for improving the techno-functional properties of these native grains. The synergy between this knowledge and modern processing technologies, such as extrusion, enables the expansion of nutritious and functional gluten-free foods, diversifying the use of various Andean maize varieties through new food matrices. Additionally, extrusion represents a clean technology with a reduced environmental impact. It is a continuous high-temperature, short-time process; it maximizes resource use, greatly reducing water and energy consumption compared to traditional processes. It also decreases effluent production and allows for the reuse of byproducts from the agri-food chain, supporting a circular economy [5]. This work aims to add value to regional Andean maize production through the on-site production of processed foods and describe their techno-functional properties to support sustainable local food systems, revaluing their biodiversity as a key strategy to enhance the population’s quality of life and strengthen their cultural identity.

2. Materials and Methods

2.1. Maize Races

Cuzco, Bolita, Culli, Capia, Morocho, Perlita, Amarillo, Garrapata, and Chulpi Andean maize races were studied. They were provided by regional producers, operating in family farming systems characterized by low levels of mechanization and a heavy reliance on local labor.

2.2. Applied Technologies

Roasting: Whole grains were roasted in a tray oven 5–10 minutes at 220–280 °C, then were cooled to room temperature and stored in polyethylene bags [4,5].

Cooking extrusion: Whole flour was conditioned at 28% of moisture 2 h before the cooking extrusion process. A Brabender KE 19 single-screw extruder with 2:1 compression ratio and 3 mm nozzle was used. The screw speed was 60 rpm and the feed speed was 20 rpm. The extrusion temperature range used was 40–120 °C depending on the production process. The extrudates were collected in trays and dried in an oven at 30 °C for 12 h [6].

Alkaline extrusion: At 12 h before the process, 0.25 g of Ca(OH)₂/100 g flour was added to each whole meal flour sample, then they were conditioned at 28% humidity, mixed 3 min, and stored in polyethylene bags in the refrigerator. The extrusion was carried out in the same conditions as cooking extrusion. The extrudates were dried in the oven at 30 °C for 12 h [7].

Nixtamalization: The maize grains were mixed with water in a 1:3 ratio, and 2% Ca(OH)₂ was added. After 40 min of cooking, the mixture was left for 24 h. Then the liquid was drained, and the nixtamalized maize was washed with tap water and dried at 40 °C in a forced convection oven. The samples were ground in a hammer mill to a particle size of ≤250 µm [6].

Fermentation: Doughs prepared with native flour and sterile water (1:2.75) were inoculated (10⁷ CFU/g) with Lactobacillus Plantarum CRL 2080, cells from the first culture grown (8 h) in MRS. Fermentation took place for 0–42 h. The fermented dough was spread out on trays for drying at 40 °C in a forced-flow oven until constant humidity (8%) was reached, then ground and packaged in polyethylene bags at room temperature.

3. Results

Developed Products

The treatment of maize flour by extrusion was carried out under the operating conditions detailed in

Table 1. Extrusion conditions and application in foods industrial products.

Process Conditions	Shearing	Gelatinization Degree	Complex Lipids	Rpm	Product
T = 60–90 °C H = 30–40%	Low (alkaline)	30–50%	40–70%	60	Laminated dough
T = 80–100 °C H = 28–32%	Intermediate	40–90%	56–75%	60	Pastas like product
T = 100–140 °C H = 15–25%	High	60–95%		80–120	Leavened breads
T = 80–90 °C H = 25%	Intermediate	25–50%	50%	60	Sauces

to obtain foods such as dry pasta and modified flours to make leavened and beaten bakery products, laminated doughs, and sauces.

Gluten-free dried pasta: Extrusion of Capia and Morado maize flours at 80 and 100 °C with 28% moisture content produced pasta with suitable sensory and cooking properties. These products exhibited low cooking losses (8%). Treatment at 100 °C resulted in paste with a degree of gelatinization of 88.19% and 75% complexed lipids. In contrast, at 80 °C, the gelatinization degree and lipid complex formation were lower, reaching 67% and 56.67%, respectively. However, the formation of high-molecular-weight insoluble protein aggregates was observed. Sensory analysis carried out with celiac and non-celiac consumers showed more palatable pasta compared to commercial gluten-free products [8].

Laminated doughs: Low-shear alkaline extrusion of Cuzco maize produced modified flours with a low degree of gelatinization. These flours allowed the production of gluten-free empanada caps with rheological and textural properties suitable for assembly and baking, both in the oven and by frying, without the need for texturizing additives [7].

Sauces: Extrusion (80 °C, 30% humidity) was compared with roasting (250 °C, 5 min) in Cuzco (soft endosperm) and Morocho (hard endosperm) maize flours. Extrusion generated greater modifications in the Cuzco race, reaching 85% gelatinization. In the Morocho race, a higher content of damaged starch (52%) was detected, derived from greater shear stress. Roasting only caused significant changes in the Cuzco breed, with partial gelatinization of 26.18% and an increase in water absorption capacity (WHC) from 2.37 to 3.51 g water/g flour. White sauce-type dressings were formulated; those made with extruded Morocho flour presented an apparent viscosity (ƞap) of 6947 mPa s and low syneresis (26%) at 48 h [9].

Beaten dough (layer cakes): Capia and Culli maize flours were treated by extrusion and nixtamalization. In Capia flour, both treatments significantly increased the WHC (6.67–7.71 g water/g flour). In contrast, in Culli flour, the WHC decreased. When gluten-free layer cakes were formulated with 1:1 blends of native and treated flours, extruded flours from both races increased hardness (7844 gf) and cohesiveness (0.42). Blends with nixtamalized flours reduced hardness (940 gf) but maintained a structure comparable to that of a commercial product with gluten.

Sourdough breads: Extrusion and extrusion-fermentation of whole-grain Capia and Bolita maize flours reduced free lipid content by 36% to 76%. Replacing native flours with treated flours in gluten-free bread production decreased specific volume (from 1.73 to 1.51 cm³/g) and increased hardness, gumminess, and chewiness. However, it also improved bread elasticity, cohesion, and resilience. Breads made with treated Capia flour showed significantly greater textural improvement (p < 0.0001) than those made with Bolita flour [10,11].

4. Discussion

The functionality of the modified maize flours, and consequently, the properties of the final products, depended on the interaction between the intrinsic characteristics of each maize race and the conditions of the extrusion process [12]. The combination of temperature, humidity, and screw speed determined the shear energy transferred to the flours, which modulated the degree of macromolecular transformations such as starch gelatinization, protein denaturation, and the formation of intermolecular complexes [11].

In the case of gluten-free pasta-like products, the cooking quality and the improvement in firmness and elasticity are attributed to the formation of a stable network [13]. This network, composed of retrograded starch, amylose-lipid complexes, and protein interactions, prevents the leaching of solids during cooking [9]. The use of different extrusion temperatures (80 and 100 °C) demonstrated how a distinct balance between thermal and mechanical energy can favor different types of interactions. At 100 °C, gelatinization and the formation of lipid-amylose complexes predominated, while at 80 °C protein aggregation was promoted, achieving in both cases a final product of high quality and acceptability [13].

For laminated doughs, the low-shear alkaline extrusion process was key. The low degree of gelatinization, combined with the increase in soluble fiber due to the action of calcium hydroxide, directly impacted the rheological properties, increasing the dough’s extensibility and strength. This result is of great technological relevance, as it allows for reducing or eliminating the dependence on hydrocolloids and other additives commonly used in gluten-free products [5].

In sauce formulation, extruded flour from the Morocho race exhibited the best performance. In this case, the combination of the degree of gelatinization, high content of damaged starch (52%), and protein denaturation allowed for greater water retention, resulting in a stable emulsion with high viscosity and low syneresis. So, the choice of raw material is critical, since the vitreous endosperm of the Morocho race drastically affected starch structures during extrusion compared to the floury endosperm of the Cuzco race [11].

In layer cakes, the results suggest a complex interaction between flour macro components. The difference in composition between Capia and Culli flours (the latter with a lower proportion of starch and a higher content of lipids and proteins) explains the opposite WHC response to the treatments. However, the formation of amylose-lipid complexes in Culli flour appears to compensate for the decrease in WHC, improving its technological properties [2].

In sourdough breads, although extrusion and fermentation improved cohesion and resilience parameters, the higher protein and fiber content in the Bolita breed could have negatively affected volume and hardness [11]. This could be due to greater competition for water among starch, protein, and fiber, which limit starch hydration for gelatinization [14]. In contrast to the possible physical interference of fiber in crumb formation, the formation of amylose-lipid complexes during processing appears to be a key factor that positively contributed to the textural improvements observed in both breeds [11].

5. Conclusions

The obtained results contributed to the socioeconomic improvement of rural families in the Andean region with sustainable alternatives involving simple technologies applicable in the region. This also contributed to the recovery of culinary heritage and the promotion of agricultural biodiversity.