Formulation of a Commercial Quality Index for Avocado Produced in an Inter-Andean Valley

Abstract

This study aimed to formulate a commercial quality index (CQI) for avocados (Persea americana Mill) produced in an inter-Andean valley in southern Peru. Thirty-eight commercial quality parameters of Hass and Fuerte avocados were evaluated under the marketing and export protocols approved in the Codex Alimentarius CXS 197-1995 issued by FAO and the Peruvian technical standard NTP 011.018. The index was formulated using information gathered from 44 experts in the Apurimac region. To weight the commercial quality parameters, the Delphi method was used, with the cooperation of expert producers and marketers, from which a weighted equation was formulated for the commercial quality index of Hass (CQI_h) and Fuerte (CQI_f) avocados. Fifteen parameters of interest were found for the formulation of the quality indexes for both varieties, which reported more than 50% coincidence among experts, based on physical and sensory evaluation. The CQI proposal would be a tool to help improve the quality attributes of avocado growers.

1. Introduction

In recent years, poverty in Peru has increased, affecting 45.7% of rural areas in 2020; of this, 50.4% corresponds to the rural highlands [1]. To try to reverse these trends, the inhabitants of these areas have dedicated themselves to emerging crops, especially avocado (Persea americana Mill), whose production increased from 4403.2 to 4416.4 tons in the period 2018 to 2019, with a slight decrease in 2020 (4399.2 tons) [2].

Since agriculture is one of the most important economic activities in the inter-Andean zones, it is necessary to know the avocado marketing-export parameters stipulated in the Codex Alimentarius, to provide tools and information to avocado farmers that will allow them to improve the marketing of this product.

The production and consumption of this seasonal fruit have increased in recent years, not only in Peru but also in other countries through exports [3,4,5,6]. This increase in production is due to the greater area of avocado plantations in the inter-Andean valleys of Peru [7]. Also, this fruit offers nutritional benefits such as improving metabolism, high content of unsaturated lipids [8], and richness in minerals, antioxidants, anti-inflammatory, vitamin E, and phytochemical compounds that promote human health [7,9,10,11,12,13,14].

The rapid growth of the avocado market has been in North America and Europe thanks to various socioeconomic and marketing factors [15,16,17], leading to an increase in production in recent decades; between 2000 and 2020, world production grew from 2,700,076 tons to 8,059,359 tons; in 2020, the main producing countries were Mexico, Dominican Republic, Indonesia, Colombia, Peru, United States, Brazil, Chile, Kenya, and China. America is the region with the highest production share in the world, with 71.8% [18].

Marketing contemplates a set of activities within the process by which a good or service is made available for customer consumption and is considered a network that provides value to the customer [19]. However, to market avocado and, in the best of cases, to export it, certain quality parameters must be met regarding minimum requirements, dry matter, ripeness requirements, external aspects, and avocado size [20,21].

According to the Food and Agriculture Organization of the United Nations (FAO) [22], avocado varieties must meet minimum parameters for marketing, such as the product must be whole and healthy for human consumption, free of any foreign matter, free of pests and abnormal external humidity, free of foreign odors and flavors, and have a peduncle smaller than 10 mm; the avocado must reach a physiological development that guarantees the ripening of the product and allows the transport and handling to ensure that it arrives at its destination in a satisfactory state.

All these parameters are included in the Codex Alimentarius with code CXS 197-1995 [22], a standard published in 1995, amended in 2005, and revised in 2013. In Peru, the Institute for the Defense of Competition and the Protection of Intellectual Property (INDECOPI) issued technical standard NTP 011.018 [23], which includes the parameters established by FAO in the Codex Alimentarius. It also includes aspects related to avocado damage and defects as quality parameters.

Stanford [24] mentions that, since new quality parameters were imposed in Mexico (avocado’s country of origin) [25], experts associate phytosanitary quality with the commercial quality of the product. Therefore, they suggest changing production and post-harvest practices, since having more quality parameters, which are accompanied by systematic methods of evaluation and verification, in theory, should benefit producers.

An important aspect of the present study was to know the commercial quality index of Hass and Fuerte avocado varieties that would help to determine their commercial quality according to the parameters found. In this sense, Robson et al. [26] used satellite images, geographic information systems, and Google Earth in their research, tools that proved to be effective in defining the spatial variability of the condition of Hass avocado plantations and fruit; they also took post-harvest fruit quality measurements to formulate indexes based on pigments and fruit structure.

Knowing the exportable quality of avocado fruit involves managing quality parameters such as color, texture, shape, size, among, and others, which allows the quality of the fruit to be perceived at first sight. The proposal for a quality index would make it possible to establish quality criteria through a single numerical data, including parameters with the greatest impact on the properties of avocado fruit.

Although the Codex Alimentarius CXS 197-1995 and NTP 011.018 indeed establish parameters for avocados, there is no commercial quality index that would make it possible to know the criteria and conditions of commercial quality, which could be introduced in the market as an easily understandable quality tool. This would allow local producers and traders or exporting companies to position the product appropriately.

The study was carried out using the Delphi method, which allows obtaining structured information from experts in agricultural product marketing [27,28,29,30,31]. It also allows obtaining information from individuals on relevant aspects involving quality, service, organization, and promotion. This allows for transforming the individual criteria of each expert into a collective or superior group judgment [32,33,34,35]. For this purpose, methodological components were considered to make it possible to form a group of experts based on the number of members, experience, and professional background; these aspects lead to obtaining reliable information [36,37,38].

2. Materials and Methods

2.1. Study Area

The study was conducted in an inter-Andean valley located in the Apurimac region, Perú, with coordinates 13°39′20.02″ S 73°23′13.99″ W for Andahuaylas; 13°31′22″ S 73°43′42″ W for Chincheros and 13°38′2″ S 72°52′53″ W for Abancay, with a Cwb climate according to the Köpen classification (temperate climate with winters).

Genetic Material

Information was collected on two varieties (Hass and Fuerte) produced in the inter-Andean valley located in the Apurimac region, Perú. Information was provided by specialists, independent growers, and members of avocado associations during the avocado harvesting season.

The Fuerte variety has an elongated shape with a narrower end, green color, weight between 170 and 500 g, and length approximately 14 cm. The Hass variety has an oval pyriform shape, with thick and rough skin, dark green color, weight between 200 and 300 g, and length approximately 11 cm (Figure 1).

Figure 1. Fuerte and Hass Avocado.

2.2. Quality Evaluation Parameters

Parameters considered include whole, healthy, characteristic, clean, undamaged, free of damage, free of odor, free from foreign taste, temperature damage, peduncle, harvest, maturity, dry matter, surface appearance, discoloration, discoloration, injury, contaminants, frost damage, sunburn, open wound, rotting, conservation, and calibers.

These criteria are established by the technical standards issued by the Food and Agriculture Organization of the United Nations (FAO) and the Commission for Standardization and Control of Non-Tariff Trade Barriers of the National Institute for the Defense of Competition and Protection of Intellectual Property (INDECOPI, Peru).

2.3. Parameter Discrimination

The experts were avocado producers and exporters, as well as specialists from the Avocado Project of the Regional Government of Apurimac; the experts were informed of the importance of the Delphi method, the criteria and rounds that are applied, the brainstorming technique, working groups, and informative talks.

The Delphi method was applied, which consisted of approaching the conformity of a group of experts based on their analysis. To determine the parameters with which the avocado commercial quality index was constructed, an evaluation by experts was applied where the parameters were discriminated, going from 38 to 15 parameters, accepting those parameters that were accepted by more than 50% of the experts. In the second stage, the weighting of each of these 15 parameters in the formulation of the avocado commercial quality index was determined. Data were collected from the inter-Andean valleys of Apurimac (Figure 2).

Figure 2. Avocado varieties’ producing areas.

2.4. Formulation of Indices

The formulation of the avocado commercial quality indexes was developed by weighting the parameters established in the first stage of the Delphi method. This weighting was obtained by finding the average of the results of the 44 experts who evaluated these parameters.

2.5. Statistical Tools

The study aimed to identify the most influential parameters on avocado quality and to propose a commercial quality index (CQI). The results obtained from the evaluation of the parameter weights collected from the expert judgment were fitted to linear and nonlinear mathematical models, using the R² fit coefficient as the fitting criterion, through the Curve Expert Professional version 2.7.3 software, mode demo.

3. Results

3.1. Discrimination of Parameters

The evaluated parameters that were accepted by more than 50% of the respondents, were chosen to continue with the second round of the Delphi method; of the 38 evaluated parameters, 18 (47.37%) parameters were accepted as shown in Table 1. On the other hand, the parameters were unified into a single parameter so that 15 parameters were considered for the second round.

Table 1. Parameters evaluated for Hass and Fuerte avocados.

Parameters	Definition	Score	%	Result
Being whole	The fruit must not be broken	8	18.18	NA
To be Healthy	The fruit must not be deteriorated	6	13.64	NA
Maintain property	The fruit must maintain the physiological characteristic	38	86.36	A
Be clean	The fruit must be free of visible foreign matter	30	68.18	A
Free of damage	The fruit must be free of pests	28	63.64	A
Free of any odor	The fruit must maintain the characteristic odor	13	29.55	NA
Free from foreign taste	The fruit must maintain its characteristic flavor	13	29.55	NA
Temperature damage	The fruit must not be damaged by high or low temperature	28	63.64	A
Peduncle	Small branch supporting the fruit	31	70.45	A
Harvest of the product	Fruit harvesting	28	63.64	A
Maturity physiological	State of the fruit that allows the culmination of the ripening process	8	18.18	NA
Dry matter content	Solid matter remaining after dehydration of the fruit	38	86.36	A
Surface appearance	Defects affecting the general appearance of the fruit	25	56.82	A
Discoloration	Loss of natural color of the fruit	29	65.91	A
Injury	Injuries caused by fruit handling	24	54.55	A
Contaminants	Agent, matter or substance that impairs the safety of the fruit	32	72.73	A
Frost damage	Loss of the natural color of the fruit due to intense cold	28	63.64	A
Sunburn	Loss of the natural color of the fruit due to excessive sunlight	26	59.09	A
Open wound	Injury to the fruit involving the pulp	11	25.00	NA
Rot	Damage to skin or pulp caused by microorganisms	13	29.55	NA
Preservation	The fruit does not have any deterioration of the skin or flesh	26	59.09	A
Avocado caliber 2	Weight over 1220 g	0	0.00	NA
Avocado caliber 4	Weight between 781 and 1220 g	3	6.82	NA
Avocado caliber 6	Weight between 576 and 780 g	5	11.36	NA
Avocado caliber 8	Weight between 456 and 576 g	6	13.64	NA
Avocado caliber 10	Weight between 364 and 462 g	3	6.82	NA
Avocado caliber 12	Weight between 300 and 371 g	6	13.64	NA
Avocado caliber 14	Weight between 258 and 313 g	23	52.27	A
Avocado caliber 16	Weight between 227 and 274 g	11	25.00	NA
Avocado caliber 18	Weight between 203 and 243 g	13	29.55	NA
Avocado caliber 20	Weight between 184 and 217 g	28	63.64	A
Avocado caliber 22	Weight between 165 and 196 g	10	22.73	NA
Avocado caliber 24	Weight between 151 and 175 g	5	11.36	NA
Avocado caliber 26	Weight between 144 and 157 g	26	59.09	A
Avocado caliber 28	Weight between 134 and 147 g	25	56.82	A
Avocado caliber 30	Weight between 123 and 137 g	10	22.73	NA
Avocado caliber 32	Weight between 80 and 123 g	6	13.64	NA
Avocado caliber S3	Weight between 80 and 123 g for Hass	4	9.09	NA

Where NA is Not accepted; A is Accepted.

3.2. Parameter Weighting

After the first round, the marketing-export parameters for Hass and Fuerte avocado varieties were determined; the accepted parameters are shown in Table 1.

3.3. Formulation of the Commercial Quality Index

With the information from the second round, the data of the commercial quality parameters for the Hass and Fuerte varieties were adjusted to the rational mathematical model (Equation (1)), whose adjustment coefficient R² was close to unity. The results are shown in Table 2 and Table 3 for the Hass and Fuerte varieties, respectively.

$$y={\displaystyle \frac{a+bx}{1+cx+d{x}^2}}$$

(1)

where $y$ is value of the quality parameter from 0 to 100; $x$ is avocado quality parameter; and a, b, c are constants of the model.

Table 2. Quality parameter values for the Hass variety.

Parameter (Q)	R2	Q(x) for 0	Q(x) for 100	a	b	c	d
Maintain property	99.37	3.59	1.27	158.50	−44.23	0.11	−0.04
Be clean	99.90	3.96	1.07	127.91	−32.45	−0.05	−0.01
Free of damage	99.27	3.00	1.16	205.94	−68.13	0.57	−0.27
Temperature damage	99.17	3.00	1.18	218.38	−72.76	0.63	−0.29
Peduncle	99.26	2.09	1.30	148.40	−51.21	−0.03	−0.08
Harvest of the product	99.62	3.00	1.05	127.85	−42.86	−0.12	−0.03
Dry matter content	99.91	1.05	3.80	−121.38	−118.09	0.80	−0.06
Surface appearance	99.48	1.00	3.66	−235.50	242.53	2.64	−0.30
Discoloration	99.17	3.00	1.30	355.54	−117.79	1.47	−0.52
Injury	99.57	2.98	1.27	275.74	−92.38	0.89	−0.36
Contaminants	99.80	3.00	1.23	147.16	−49.03	−0.04	−0.05
Frost damage	98.80	3.00	1.16	117.65	−38.73	−0.26	0.03
Sunburn	99.34	3.00	1.25	150.48	−50.29	0.02	−0.08
Preservation	99.70	2.98	1.07	133.37	−44.93	−0.07	−0.05
Caliber	96.97	6.21	4.68	89.44	−14.16	−0.36	0.04

Table 3. Quality parameter values for the Fuerte variety.

Parameter (Q)	R2	Q(x) for 0	Q(x) for 100	a	b	c	d
Maintain property	98.76	2.77	1.16	2989.52	−107.82	1.34	−0.55
Be clean	99.90	3.96	1.07	127.91	−32.45	−0.05	−0.01
Free of damage	99.27	3.00	1.16	205.94	−68.13	0.57	−0.27
Temperature damage	99.17	3.00	1.18	218.38	−72.76	0.63	−0.29
Peduncle	99.26	2.09	1.30	148.40	−51.21	−0.03	−0.08
Harvest of the product	99.62	3.00	1.05	127.85	−42.86	−0.12	−0.03
Dry matter content	99.91	1.05	3.80	−121.38	−118.09	0.80	−0.06
Surface appearance	99.48	1.00	3.66	−235.50	242.53	2.64	−0.30
Discoloration	99.17	3.00	1.30	355.54	−117.79	1.47	−0.52
Injury	99.57	2.98	1.27	275.74	−92.38	0.89	−0.36
Contaminants	99.80	3.00	1.23	147.16	−49.03	−0.04	−0.05
Frost damage	98.80	3.00	1.16	117.65	−38.73	−0.26	0.03
Sunburn	99.34	3.00	1.25	150.48	−50.29	0.016	−0.08
Preservation	99.70	2.98	1.07	133.37	−44.93	−0.07	−0.05
Caliber	97.86	4.14	3.52	5068.00	−1.19	−0.56	0.08

The weighting of the quality parameters is reported in Table 4. It was observed that the parameter “free of damage” had the highest weighting for the Hass variety, while for the Fuerte variety it was “harvest of the product” (0.08); the other parameters were between 0.06 and 0.07 for both varieties.

Table 4. Avocado commercial quality index formula components.

Component	Hass Factor	Fuerte Factor
Maintain property	0.07	0.07
Be clean	0.07	0.07
Free of damage	0.08	0.07
Temperature damage	0.06	0.06
Peduncle	0.06	0.06
Harvest of the product	0.07	0.08
Dry matter content	0.07	0.07
Surface appearance	0.07	0.07
Discoloration	0.06	0.06
Injury	0.06	0.06
Contaminants	0.07	0.06
Frost damage	0.06	0.06
Sunburn	0.06	0.06
Preservation	0.07	0.07
Caliber	0.06	0.06

3.4. Application of the Delphi Method in the Proposal of a Commercial Quality Index for Hass and Fuerte Avocado

The relationship of Qi and Wi allows for proposing the commercial quality index, which is composed of 15 parameters, for both varieties under study. One of the ways to group them and obtain a single CQI value is through the weighted average, which measures the weight of each parameter of importance [39]. This index is represented by the Equation (2).

$$CQIx={\sum }_{n=1}^{15}Qi\times Wi$$

(2)

where Qi, is a quality component i (Maintain property, be clean, free of damage and other); Wi, is parameter weighting; CQI is the avocado commercial quality index, and x for the Hass variety is h and for Fuerte is f.

4. Discussion

One of the important components in the commercial quality parameters of avocados is that the product must be clean, including that it must not contain insects. However, if the avocado fruit were found to contain insects, it would be discarded for commercialization, since this aspect is a parameter required by the international market. Avocado marketing is affected worldwide by pests and diseases [40,41,42,43].

The Ministry of Foreign Relations, Perú, mentions that to pack avocado and be accepted in the United States market, the fruit must comply with seven CFR 31956-50 [44] criteria, which implies that avocado is packed in environments that are free of insects within 24 h after harvesting. So, before packing the avocado, debris or weeds that may contain any insects must be removed, maintaining the organoleptic characteristics and preserving its appearance, which facilitates its commercialization [45,46].

Another important component is that it is free of damage such as pests. Díaz Vásquez et al. [47] mentioned that sanitary measures limited the entry of Colombian avocado to the United States market, and Álvarez Flores et al. [48] mentioned that exports of Ecuadorian avocado decreased in the period from 2011 to 2015 due to the presence of pests in the cultivation areas attacking the avocado fruit as the main cause.

Regarding the parameter of frost or cold damage, it is considered important because this damage reduces the useful life of avocados, considerably affecting their commercialization in international markets [49,50]. On the other hand, it is important to control fruit lesions, especially during the processing stage, since lesions increase considerably [51].

The avocado commercial quality index (CQI) proposed in this research integrates the criteria approved by the Food and Agriculture Organization of the United Nations (FAO) in Codex CXS-197-1995 [22] and the criteria established in the Peruvian technical standard for avocado approved by the National Institute for the Defense of Competition and Intellectual Property (INDECOPI, Perú); therefore, the use of this commercial quality index (CQI) provides more criteria for a better evaluation of the commercial quality.

The implementation of this new avocado quality index must complete socialization stages among marketing channels to integrate quality criteria. However, the high demand for this fruit may generate a lack of interest in its application in the industry because in many cases the demand exceeds the market supply. Nonetheless, in the long term, this avocado commercial quality index can become a useful tool for standardizing production and marketing processes at the local and international levels.

The Delphi method made it possible to obtain information from experts in avocado marketing. This method has been used for various types of research, seeking the knowledge of experts in a given subject to reach a consensus on knowledge in an interdisciplinary and transdisciplinary manner [34], making it possible to better understand problems, opportunities, forecasts, and solutions [29]. This tool has made it possible to establish commercial quality criteria for food products (fruits, vegetables, tubers, grains, and cereals) and to forecast future trends by identifying key factors [52,53,54].

Likewise, the information gathered using the Delphi method made it possible to formulate the commercial quality index using weighted equations, since this method has the potential to make combined use of statistical techniques [55], including the elaboration of a digital twin model [56], creating scenarios to predict the future [57], or making use of a rational model as in the case of this study.

This index could be used in avocado-producing areas, mainly in Latin American countries. It could also be applied in avocado-importing countries.

5. Conclusions

Hass and Fuerte avocado fruits, produced in the inter-Andean valley located in the department of Apurimac, have become a highly exportable product. The parameters of the quality index for the commercialization-export of Hass and Fuerte avocados in the inter-Andean valley were determined. Initially, 38 marketing-export parameters were identified.

The application of the Delphi method to the experts allowed the identification of 15 relevant parameters: maintain the property, be clean, free of damage, temperature damage, peduncle, harvest of the product, dry matter content, surface appearance, discoloration, injury, contaminants, frost damage, sunburn, preservation, and caliber. The use of the Delphi method is a decision-making tool for avocado growers, allowing the formulation of a commercial quality index.

The commercial quality index (CQI), being a tool to determine the quality of avocado fruit, could be influenced by elements such as producer organization, production volume, use of agrochemicals, market demand and supply, and climatic variations. These aspects can affect the performance and robustness of the proposed quality index, so a study including these elements is recommended.

The study included the formulation of a quality index (CQI) for the commercialization of avocado, specifically Hass and Fuerte varieties, which are produced in the inter-Andean valley of Apurimac. However, additional aspects should be considered for application to other varieties.